U.S. patent application number 10/027295 was filed with the patent office on 2002-10-03 for absorbent article and method for maintaining or improving skin health.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Elder, Gretchen Louise, Klofta, Thomas James, Roe, Donald Carroll.
Application Number | 20020143304 10/027295 |
Document ID | / |
Family ID | 25453340 |
Filed Date | 2002-10-03 |
United States Patent
Application |
20020143304 |
Kind Code |
A1 |
Elder, Gretchen Louise ; et
al. |
October 3, 2002 |
Absorbent article and method for maintaining or improving skin
health
Abstract
Disclosed is a method for maintaining and/or improving skin
health in the area of a wearer covered by an absorbent article. The
absorbent article includes a vapor permeable backsheet, a liquid
pervious topsheet positioned in facing relation with the backsheet,
an absorbent core located between the backsheet and the topsheet.
The absorbent article also includes skin care compositions thereon
for maintaining and/or improving skin health.
Inventors: |
Elder, Gretchen Louise;
(Blue Ash, OH) ; Roe, Donald Carroll; (West
Chester, OH) ; Klofta, Thomas James; (Cincinnati,
OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
|
Family ID: |
25453340 |
Appl. No.: |
10/027295 |
Filed: |
December 20, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10027295 |
Dec 20, 2001 |
|
|
|
08926532 |
Sep 10, 1997 |
|
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Current U.S.
Class: |
604/360 ;
604/367; 604/385.06 |
Current CPC
Class: |
H03G 3/3036 20130101;
H03F 2200/504 20130101; A61L 15/46 20130101; A61F 13/51305
20130101; A61L 15/34 20130101; A61L 15/44 20130101; A61F 13/8405
20130101; A61L 15/48 20130101 |
Class at
Publication: |
604/360 ;
604/367; 604/385.06 |
International
Class: |
A61F 013/15; A61F
013/20 |
Claims
What is claimed is:
1. A disposable absorbent article which defines a front waist
region, a rear waist region, and a crotch region which
interconnects said front and rear waist regions, said absorbent
article comprising: a) a vapor permeable backsheet which defines a
Water Vapor Transmission Rate of at least about 2300 grams per
square meter per 24 hours, calculated according to a Water Vapor
Transmission Test as set forth herein; b) a liquid pervious
topsheet which is positioned in facing relation with said
backsheet; c) an absorbent core located between said backsheet and
said topsheet; and d) a skin care composition on at least a portion
of a wearer-contacting surface of said absorbent article which
comprises from about 10 to about 95 weight percent of an emollient
and from about 5 to about 90 weight percent of a wax.
2. The absorbent article of claim 1 wherein said composition
further comprises a viscosity increasing agent selected from the
group consisting of alkyl galactomannan, silica, talc, magnesium
silicate, sorbitol, colloidal silicone dioxide, magnesium aluminum
silicate, zinc stearate, sesquioleate, cetyl hydroxy ethyl
cellulose and other modified celluloses, and mixtures thereof.
3. The absorbent article of claim 1 wherein said emollient is
selected from the group consisting of sucrose ester fatty acids,
fatty acid esters, alkyl ethoxylates, fatty acid ester ethoxylates,
polysiloxanes, fatty alcohol ethers, polyethylene glycol and
derivatives thereof, propylene glycol and derivatives thereof,
glycerine and derivatives thereof, propoxylated fatty alcohols,
fatty esters of polyhydroxy alcohols, lanolin and its derivatives,
and mixtures thereof.
4. The absorbent article of claim 1 wherein said emollient is a
petroleum-based emollient selected from the group consisting of
petrolatum, mineral oil, and mixtures thereof.
5. The absorbent article of claim 1 wherein said wax is selected
from the group consisting of camauba, ozokerite, beeswax,
candelilla, paraffin, ceresin, esparto, ouricuri, rezowax,
isoparaffin, other mined and mineral waxes, and mixtures thereof.
Description
[0001] This is a divisional application claiming the benefit of
co-pending U.S. application Ser. No. 08/926,532, filed on Sep. 10,
1997 by Elder et al.
TECHNICAL FIELD
[0002] This application relates to a method for maintaining or
improving skin health in wearers of absorbent articles such as
diapers, training pants, adult incontinence devices, feminine
hygiene products, and the like. More particularly, the application
relates to a method comprising the repeated use of absorbent
articles that deliver a composition to the wearer's skin, so as to
provide a skin protective barrier and/or a therapeutic benefit.
BACKGROUND OF THE INVENTION
[0003] Many types of disposable absorbent products, such as
diapers, are available that have a high capacity for absorbing
urine and other body exudates. Disposable products of this type
generally comprise some sort of liquid-pervious topsheet material,
an absorbent core, and a liquid-impervious backsheet material.
Although these types of absorbent structures may be highly
efficient for the absorption of liquids, it is well recognized that
long-term wear of such structures may lead to skin which is
compromised in terms of being over hydrated or exposed to skin
irritants commonly found in body exudates. It is generally knowi
that skin under absorbent articles is more susceptible to skin
disorders, including diaper rash, erythema (i.e., redness), heat
rash, abrasion, pressure marks and skin barrier loss. For example,
21 C.F.R. 333.503 defines diaper rash as "[a]n inflammatory skin
condition in the diaper area (perineum, buttocks, lower abdomen,
and inner thighs) caused by one or more of the following factors:
moisture, occlusion, chafing, continued contact with urine or feces
or both, or mechanical or chemical irritation."
[0004] To address the concerns of skin disorders associated with
wearing absorbent articles, the caregiver often applies skin
protective products such as Vaseline.RTM., medicated ointments,
powders, etc. to the buttocks, genitals, anal and/or other regions
before placing the absorbent article on the wearer. This procedure
usually involves the caregiver applying the skin protective to
their hands, and then wiping the same on the skin of the infant. To
eliminate the need for this wasteful, messy, time-consuming, and
easily forgotten procedure, there have been attempts to prepare
absorbent articles which contain a protective or therapeutic skin
care substance on the article's topsheet.
[0005] U.S. Pat. No. 3,585,998 to Hayford et al. teaches a
disposable baby diaper, an interior liner of which carries an array
of pressure-rupturable capsules containing baby oil. The patent
teaches that it is desirable to break the capsules prior to using
the diaper by applying pressure with such household items as a
rolling pin, hand iron, etc. Articles disclosed by this patent have
serious drawbacks. Namely, unless the capsules are ruptured by
applying pressure prior to using the diaper or the bandage, the
skin-care substance contained in the capsules is either not
delivered at all or is delivered non-uniformly leaving some areas
of skin uncoated.
[0006] U.S. Pat. No. 3,489,148 to Duncan et al. teaches a baby
diaper comprising a hydrophobic and oleophobic topsheet wherein a
portion of the topsheet is coated with a discontinuous film of
oleaginous material. A major disadvantage of the diapers disclosed
in the Duncan et al. reference is that the hydrophobic and
oleophobic topsheets are slow in promoting transfer of urine to the
underlying absorbent cores.
[0007] U.S. Pat. No. 5,643,588 to Roe et al. addresses some of the
concerns presented by prior absorbent articles which were designed
to deliver a skin protective material. In particular, Roe describes
an absorbent article whose topsheet is surface treated with a
lotion that comprises an emollient for facilitating easier cleaning
of feces and other exudates and an agent which immobilizes the
lotion so that it does not migrate from the point of initial
application.
[0008] While the prior art describes articles designed to deliver
compositions to provide skin care benefits, the prior art has
failed to describe a regimen which results in maintained or
improved skin health in regions of the wearer's body covered by
absorbent articles, where the regimen does not require intervention
from the caregiver in the form of manual application of skin care
compositions. That is, the prior art has not recognized the
importance of the repeated use of absorbent articles that
automatically deliver sufficient levels of a composition to the
wearer's skin that allows the maintenance or improvement of skin
health in the region of the wearer covered by the absorbent
article.
[0009] Accordingly, it would be desirable to provide a method: (1)
wherein the condition of skin covered by the absorbent article is
maintained in a natural, healthy condition or improved to a more
healthy condition; and (2) that does not require intervention by
the wearer or caregiver in the form of manual application of skin
care agents.
[0010] Therefore, it is an object of the present invention to
provide a method for maintaining or improving the skin health of an
absorbent article wearer comprising repeated application of
disposable absorbent articles that automatically deliver sufficient
levels of a composition. In this regard, it is an object of the
present invention to provide a method that comprises the
application of absorbent articles which have a composition on a
wearer-contacting surface, where the composition is transferable to
the wearer's skin and is effective at maintaining or improving skin
health.
[0011] These and other objects are obtained in accordance with the
present invention, as will become readily apparent upon reading the
following disclosure.
SUMMARY OF TIE INVENTION
[0012] The present invention relates to a method for maintaining
and/or improving skin health in the area of a wearer covered by an
absorbent article. The absorbent article includes a vapor permeable
backsheet, a liquid pervious topsheet positioned in facing relation
with the backsheet, an absorbent core located between the backsheet
and the topsheet. The absorbent article also includes skin care
compositions thereon for maintaining and/or improving skin health.
The method comprising the following steps:
[0013] (a) applying to the wearer an absorbent article having a
skin care composition that provides a therapeutic and/or protective
skin benefit upon transfer to the skin;
[0014] (b) transferring to the wearer at least a portion of the
skin care composition during wear; and
[0015] (c) repeating steps (a) and (b) with one or more additional
articles with sufficient frequency to maintain or improve the
health of the skin covered by the absorbent article relative to the
skin covered by an equivalent absorbent article that does not
comprise the skin care composition, and without the need for manual
application of skin protective agents (e.g., by the caregiver or
wearer).
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an absorbent article in the form of a diaper
according to the present invention.
[0017] FIGS. 2a through 2e depict the regions of a wearer of
absorbent article that are assessed for rash and erythema.
[0018] FIG. 3a is a side view showing placement of the skin analog
used in the skin care composition transfer test.
[0019] FIG. 3b is a plan view showing placement of the skin analog
used in the skin care composition transfer test.
DETAILED DESCRIPTION OF THE INVENTION
[0020] I. Definitions
[0021] As used herein, the term "comprising" means that the various
components, ingredients, or steps, can be conjointly employed in
practicing the present invention. Accordingly, the term
"comprising" encompasses the more restrictive terms "consisting
essentially of" and "consisting of."
[0022] As used herein, the term "maintained" skin health means to
preserve the natural state of healthy skin. The term "improved"
skin health refers to a reduction in the extent of adverse skin
effects. These terms describe skin health in the area covered by
absorbent articles. It will be recognized that the methods of the
present invention may both maintain and improve skin health in
different regions of an individual wearer.
[0023] As used herein, the term "skin care composition" refers to
any composition which comprises one or more agents which, when
transferred from an article to a wearer's skin, provide a
therapeutic and/or protective skin benefit. Representative
materials are discussed in detail below.
[0024] As used herein, the term "treated article" means an
absorbent article having a skin care composition on or migratable
to at least one wearer-contacting surface of that article. An
"equivalent article that does not comprise a skin care composition"
is an article that is substantially the same as a treated article,
in terms of topsheet, backsheet, absorbent core, chassis design,
cuffs, etc., but which does not comprise a skin care composition
that is transferred to the wearer during use.
[0025] As used herein, the term "wearer-contacting surface" of an
absorbent article is one or more surfaces of any article components
that contact the wearer at some time during the wear period. Wearer
contacting surfaces include, but are not limited to, portions of
the topsheet, leg cuffs, waist region, side panels, fastening tabs,
etc., which contact a wearer during use.
[0026] Other terms are defined in the specification where initially
discussed.
[0027] With respect to the skin care composition, all percentages,
ratios and proportions used herein are by weight unless otherwise
specified.
[0028] II. Methods for Maintaining and/or Improving Skin Health
[0029] As discussed, the adverse skin effects that result from the
occlusive nature of current absorbent articles are well recognized.
Efforts have been made to overcome these negative attributes by
preparing articles that deliver beneficial compositions. However,
Applicants are the first to recognize the benefit of a method
comprising frequent cycles of cumulative delivery of a skin care
composition to the wearer's skin to maintain or improve skin
health. In this regard, the present invention relates to a method
for maintaining or improving skin health in the area covered by an
absorbent article, the method comprising the following steps:
[0030] (a) applying to the wearer an absorbent article having a
skin care composition that provides a therapeutic and/or protective
skin benefit upon transfer to the skin;
[0031] (b) transferring to the wearer at least a portion of the
skin care composition during wear; and
[0032] (c) repeating steps (a) and (b) with one or more additional
articles with sufficient frequency to maintain or improve the
health of the skin covered by the absorbent article relative to the
skin covered by an equivalent absorbent article that does not
comprise the skin care composition, and without the need for manual
application of skin protective agents (e.g., by the caregiver or
wearer).
[0033] Applicants have discovered that, surprisingly, maintaining
or improving health skin under absorbent articles can be
accomplished coincidentally (or "automatically") with repeated use,
over a period of time (e.g., several days), of absorbent articles
that are treated with a composition that is transferred to the
wearer under normal usage conditions (e.g., contact, movement,
handling by the caregiver after application of the article, body
heat, etc.). Thus, while prior attempts to address skin disorders
associated with wearing absorbent articles have generally described
steps (a) or (b) of the present method, none of those attempts
appreciated the importance of step (c), corresponding to frequent
cycles of cumulative delivery of a skin care composition to the
wearer's skin to maintain or improve skin health. Applicants have
further discovered that delivery of relatively low levels of the
composition with each article wear are sufficient to obtain the
skin benefits resulting from this novel method of cumulative
composition delivery.
[0034] The article used in the present methods provides an
available source from which the skin care composition transfers
onto the skin continuously over time. As the composition is
transferred, it accumulates on the skin surface to initiate and
maintain its protective activity. As a used article is discarded
and replaced by a new one, this cycle is repeated for further
composition accumulation above and beyond what a single or original
article would have delivered on its own. Certain of the ingredients
for use in the composition are known to penetrate the stratum
comeum (e.g., petrolatum, which is preferred for use herein). Thus,
even as some amount of the composition is removed by cleaning,
bathing, etc., or even if usage of treated articles as described
herein is discontinued temporarily, some of the benefits of the
skin composition will remain with the user. As usage of treated
articles is resumed before all of the benefits of the composition
have dissipated, the user will derive benefits, in terms of reduced
erythema and/or rash, more rapidly than would a user who has not
used treated articles.
[0035] As indicated above, it is generally recognized that skin
under absorbent articles is more susceptible to degradation of that
skin's condition. Typically, cutaneous manifestations of these skin
conditions include redness (also referred to as erythema) and/or
rash. As such, Applicants describe herein a method for maintaining
or improving skin health in regions covered by an absorbent
article, wherein the desired endpoint of the method is the
reduction or avoidance of erythema and/or rash when compared to
skin covered by an equivalent absorbent article that does not
comprise the skin care composition.
[0036] Erythema and rash are the most common and well documented
adverse medical conditions present on skin covered by absorbent
articles. These conditions are readily assessed by expert skin
graders. Hence the protocol for assessing the maintenance or
improvement of skin health relies on assessment of rash and/or
erythema. The protocol for assessing reduction or avoidance of rash
and/or erythema provided by the methods of the present invention
are described in detail in the Test Methods section below. In
brief, the objective of the protocol is to determine whether use of
a test article reduces the frequency and/or severity of skin rash
and/or erythema in the diapered skin regions compared to an
equivalent, untreated article. The test method involves comparisons
of end point parameters between 2 groups of subjects who are
assigned to wear the test or the control product for 3 consecutive
weeks (a baseline week in which all subjects use the same control
product is included prior to initiating the 3-week product
comparison portion of the study). Per this approach, the skin in
the diapered region of the users of the articles is examined twice
per week at 3-4 day intervals by a clinical evaluator trained to
evaluate diaper rash and erythema using a defined scale. At the
completion of the study, the frequency and severity of diaper rash
and erythema are compared between the test and control product
groups using appropriate statistical procedures.
[0037] In one aspect, the improvement manifests itself as a
statistically significant reduction in erythema and/or rash at a
90% confidence level, relative to skin covered an equivalent
absorbent article that does not comprise the skin care composition.
In this regard, it is preferable that the reduction or will
manifest itself at a 95% confidence level.
[0038] Separately, it is recognized that one may observe large
between-group differences (i.e., in the mean) in rash and/or
erythema scores, yet due to large inter-subject variability fail to
observe traditional statistically significant differences. In this
regard, improvements of at least about 10% between group (control
and test) means, though not necessarily statistical, may be
recognized and appreciated by caregivers and users as providing
skin care benefits. In this regard, the methods of the present
invention will result in improvements in rash or erythema scores of
at least about 10%, more preferably at least about 15%, still more
preferably at least about 20%.
[0039] For purposes of the present disclosure, statistical or
non-statistical improvements, defined above, in skin condition with
regard to either erythema or rash at one or more wearer regions for
the study group as a whole, or any gender or age or size subset of
the study group, as described in the Test Method section, are
considered to provide the desired skin benefits of the present
invention. Preferably, the methods of the present invention will
provide both erythema and rash benefits, at one or more wearer
regions as described in the Test Method section.
[0040] III. Skin Care Composition
[0041] While the specific composition(s) delivered (referred to
herein as "skin care composition" and "composition") in accordance
with the present method is not the critical factor in achieving
maintained skin condition of the area under absorbent articles, it
is apparent that the composition must provide either a protective,
nonocclusive function (e.g., a relatively liquid impervious but
vapor pervious barrier) to avoid skin hyperhydration and skin
exposure to materials contained in body exudates, or it must
contain agents that deliver, either directly or indirectly, skin
care benefits. For example, indirect benefits include improved
removal of skin irritants such as feces or urine. The composition
may be in a variety of forms, including, but not limited to,
emulsions, lotions, creams, ointments, salves, powders,
suspensions, encapsulations, gels, and the like.
[0042] As used herein, the term "effective amount of a skin care
composition" refers to an amount of a particular composition which,
when applied or migrated to one or more of the wearer-contacting
surface(s) of an absorbent article(s), will be effective in
providing a protective barrier and/or delivering a skin care
benefit when delivered via absorbent articles over time. Of course,
the effective amount of composition applied to the article will
depend, to a large extent, on the particular composition used.
Nonetheless, the quantity of the composition on at least a portion
of the wearer-contacting surface of the absorbent article will
preferably range from about 0.05 mg/in.sup.2 (0.0078 mg/cm.sup.2)
to about 80 mg/in.sup.2 (12 mg/cm.sup.2), more preferably from
about 1 mg/in.sup.2 (0.16 mg/cm.sup.2) to about 40 mg/in.sup.2 (6
mg/cm.sup.2), still more preferably from about 4 mg/in.sup.2 (0.6
mg/cm.sup.2) to about 26 mg/in.sup.2 (4 mg/cm.sup.2). These ranges
are by way of illustration only and the skilled artisan will
recognize that the nature of the composition will dictate the level
that must be applied to achieve the desired skin benefits, and that
such levels are ascertainable by routine experimentation in light
of the present disclosure.
[0043] While the level of skin care composition applied to the
absorbent article is an important aspect of the present methods,
more important is the amount of composition transferred to the
wearer's skin during use of one or more treated articles. Though
the requisite level delivered to the skin to provide the desired
skin benefits will depend to some degree on the nature of the
composition employed, Applicants have found that relatively low
levels may be delivered while still providing the desired skin
effects. This is particularly true for preferred compositions, such
as that described in Example 1.
[0044] Another benefit of the present method is the controlled
application of the skin care composition to deliver the low but
effective levels of composition required. This is in contrast to
typically sporadic manual application of skin care agents, where
the caregiver/user often applies significantly greater levels of
material than are needed. Excessive materials added manually may
adversely impact the fluid handling properties of the absorbent
article, as a result of transfer from the skin to the article.
Indeed, for certain materials, such as petrolatum, the levels
applied manually may actually result in an occlusive effect,
thereby compromising the skin. A benefit of the present methods is
providing a barrier to surface moisture while avoiding occlusion of
the skin (i.e., maintaining skin breathability). Thus, the present
methods, which allow controlled composition delivery throughout the
wear period, allow transfer of optimal levels of the composition to
the skin to maintain and/or improve skin health.
[0045] The method for determining the amount of skin care
composition transferred to a wearer's skin after wearing one or
more treated articles is described in the Test Methods section
below. With regard to the level of skin care composition that is
transferred to the wearer during use of one treated absorbent
article worn for a period of about 3 hours (a typical daytime wear
time), particularly for preferred skin care compositions such as
that described in Example 1, preferred is where at least about 0.01
mg/in.sup.2 (0.0016 mg/cm.sup.2), more preferably at least about
0.05 mg/in.sup.2 (0.0078 mg/cm.sup.2), still more preferably at
least about 0.1 mg/in.sup.2 (0.016 mg/cm.sup.2), of the composition
is transferred to the skin over a three hour wear period.
Typically, the amount of composition delivered by one treated
article will be from about 0.01 mg/in.sup.2 (0.0016 mg/cm.sup.2) to
about 5 mg/in.sup.2 (0.78 mg/cm.sup.2), more preferably from about
0.05 mg/in.sup.2 (0.0078 mg/cm.sup.2) to about 3 mg/in.sup.2 (0.47
mg/cm.sup.2), still more preferably from about 0.1 mg/in.sup.2
(0.016 mg/cm.sup.2) to about 2 mg/in.sup.2 (0.31 mg/cm.sup.2), over
a three hour wear period.
[0046] For continual use of treated articles (in other words,
changes occur in accordance with normal use patterns, which
typically include changes every 3 to 4 hours during the day and a
fresh article before overnight sleep) such as for a period of 24
hours, it will be preferred that at least about 0.03 mg/in.sup.2
(0.0047 mg/cm.sup.2), more preferably at least about 0.1
mg/in.sup.2 (0.016 mg/cm.sup.2), still more preferably at least
about 0.3 mg/in.sup.2 (0.047 mg/cm.sup.2), of the composition is
transferred to the wearer's skin over the 24 hour period.
Typically, the amount of composition delivered after a period of 24
hours where treated articles are applied at each change, will be
from about 0.03 mg/in.sup.2 (0.0047 mg/cm.sup.2) to about 18
mg/in.sup.2 (2.79 mg/cm.sup.2), more typically from about 0.1
mg/in.sup.2 (0.016 mg/cm.sup.2) to about 10 mg/in.sup.2 (1.55
mg/cm.sup.2), still more typically from about 0.3 mg/in.sup.2
(0.047 mg/cm.sup.2) to about 6 mg/in.sup.2 (0.93 mg/cm.sup.2).
[0047] It will be recognized that of the numerous materials useful
in the skin care compositions delivered to skin in accordance with
the present methods, those that have been deemed safe and effective
skin care agents are logical materials for use herein. Such
materials include Category I actives as defined by the U.S. Federal
Food and Drug Administration's (FDA) Tentative Final Monograph on
Skin Protectant Drug Products for Over-the-Counter Human Use (21
C.F.R. .sctn.347), which presently include: alantoin, aluminum
hydroxide gel, calamine, cocoa butter, dimethicone, cod liver oil
(in combination), glycerine, kaolin, petrolatum, lanolin, mineral
oil, shark liver oil, white petrolatum, talc, topical starch, zinc
acetate, zinc carbonate, zinc oxide, and the like. Other
potentially useful materials are Category III actives as defined by
the U.S. Federal Food and Drug Administration's Tentative Final
Monograph on Skin Protectant Drug Products for Over-the-Counter
Human Use (21 C.F.R. .sctn.347), which presently include: live
yeast cell derivatives, aldioxa, aluminum acetate, microporous
cellulose, cholecalciferol, colloidal oatmeal, cysteine
hydrochloride, dexpanthanol, Peruvean balsam oil, protein
hydrolysates, racemic methionine, sodium bicarbonate, Vitamin A,
and the like.
[0048] Many of the FDA monographed skin care ingredients are
currently utilized in commercially available skin care products,
such as A and D.RTM. Ointment, Vaseline.RTM. Petroleum Jelly,
Desitin.RTM. Diaper Rash Ointment and Daily Care.RTM. ointment,
Gold Bond.RTM. Medicated Baby Powder, Aquaphor.RTM. Healing
Ointment, Baby Magic.RTM. Baby Lotion, Johnson's Ultra
Sensitive.RTM. Baby Cream. These commercial products may be applied
to absorbent articles to create treated articles for use in the
present methods, either with or without modification of the product
to facilitate delivery via this novel method.
[0049] As will be discussed hereinafter, the skin care compositions
useful in the methods of the present invention preferably, though
not necessarily, have a melting profile such that they are
relatively immobile and localized on the wearer-contacting surface
of the article at room temperature, are readily transferable to the
wearer at body temperature, and yet are not completely liquid under
extreme storage conditions. Preferably, the compositions are easily
transferable to the skin by way of normal contact, wearer motion,
and/or body heat. Because the composition preferably is
substantially immobilized on the article's wearer-contacting
surface, relatively low levels of composition are needed to impart
the desired skin care benefits. In addition, special barrier or
wrapping materials may be unnecessary in packaging the treated
articles useful in the methods of the present invention.
[0050] In a preferred embodiment, the skin care compositions useful
herein are solid, or more often semi-solid, at 20.degree. C., i.e.
at ambient temperatures. By "semisolid" is meant that the
composition has a rheology typical of pseudoplastic or plastic
liquids. When no shear is applied, the compositions can have the
appearance of a semi-solid but can be made to flow as the shear
rate is increased. This is due to the fact that, while the
composition contains primarily solid components, it also includes
some minor liquid components. Preferably, the compositions of the
present invention have a zero shear viscosity between about
1.0.times.10.sup.6 centipoise and about 1.0.times.10.sup.8. More
preferably, the zero shear viscosity is between about
5.0.times.10.sup.6 centipoise and about 5.0.times.10.sup.7
centipoise. As used herein the term "zero shear viscosity" refers
to a viscosity measured at very low shear rates (e.g., 1.0
sec.sup.-1) using plate and cone viscometer (a suitable instrument
is available fom TA Instruments of New Castle, Del. as model number
CSL 100). One of skill in the art will recognize means other than
high melting point components (as discussed below) can be used to
provide comparable viscosities measured for such compositions
comprising such means can be measured by extrapolating a plot of
viscosity vs. shear rate for such compositions to a shear rate of
zero at a temperature of about 20.degree. C.
[0051] Preferred compositions are at least semi-solid at room
temperature to minimize composition migration. In addition, the
compositions preferably have a final melting point (100% liquid)
above potential "stressful" storage conditions that can be greater
than 45.degree. C. (e.g., warehouse in Arizona, car trunk in
Florida, etc.). Representative compositions having these melt
characteristics are described in detail in U.S. Pat. No. 5,643,588
(Roe et al.), U.S. Pat. No. 5,607,760 (Roe et al.), U.S. Pat. No.
5,609587, and U.S. Pat. No. 5,635,191, the disclosure of each of
which is incorporated herein by reference. Specifically, preferred
compositions will have the following melt profile:
1 Characteristic Preferred Range Most Preferred % liquid at 2-50
3-25 room temp. (20.degree. C.) % liquid at 25-95 30-90 body temp.
(37.degree. C.) final melting point (.degree. C.) .gtoreq.38
.gtoreq.45
[0052] By being solid or semisolid at ambient temperatures,
preferred compositions do not have a tendency to flow and migrate
to a significant degree to undesired locations of the article to
which they are applied. This means less skin care composition is
required for imparting desirable therapeutic, protective and/or
conditioning benefits.
[0053] To enhance immobility of preferred compositions, the
viscosity of the formulated compositions should be as high as
possible to prevent flow within the article to undesired location.
Unfortunately, in some instances, higher viscosities may inhibit
transfer of composition to the wearer's skin. Therefore, a balance
should be achieved so the viscosities are high enough to keep the
compositions localized on the surface of the article, but not so
high as to impede transfer to the wearer's skin. Suitable
viscosities for the compositions will typically range from about 5
to about 500 centipoise, preferably from about 5 to about 300
centipoise, more preferably from about 5 to about 100 centipoise,
measured at 60.degree. C. using a rotational viscometer (a suitable
viscometer is available from Lab Line Instruments, Inc. of Melrose
Park, Ill. as Model 4537). The viscometer is operated at 60 rpm
using a number 2 spindle.
[0054] For compositions designed to provide a therapeutic and/or
skin protective benefit, a useful active ingredient in these
compositions is one or more skin protectants or emollients. As used
herein, the term "emollient" is a material that protects against
wetness or irritation, softens, soothes, supples, coats,
lubricates, moisturizes, protects and/or cleanses the skin. (It
will be recognized that several of the monographed actives listed
above are "emollients", as that term is used herein.) In a
preferred embodiment, these emollients will have either a plastic
or liquid consistency at ambient temperatures, i.e., 20.degree.
C.
[0055] Representative emollients useful in the present invention
include, but are not limited to, emollients that are
petroleum-based; sucrose ester fatty acids; polyethylene glycol and
derivatives thereof; humectants; fatty acid ester type; alkyl
ethoxylate type; fatty acid ester ethoxylates; fatty alcohol type;
polysiloxane type; propylene glycol and derivatives thereof;
glycerine and derivatives thereof, including glyceride,
acetoglycerides, and ethoxylated glycerides of C.sub.12-C.sub.28
fatty acids; triethylene glycol and derivatives thereof, spennaceti
or other waxes; fatty acids; fatty alcohol ethers, particularly
those having from 12 to 28 carbon atoms in their fatty chain, such
as stearic acid; propoxylated fatty alcohols; other fatty esters of
polyhydroxy alcohols; lanolin and its derivatives; kaolin and its
derivatives; any of the monographed skin care agents listed above;
or mixtures of these emollients. Suitable petroleum-based
emollients include those hydrocarbons, or mixtures of hydrocarbons,
having chain lengths of from 16 to 32 carbon atoms. Petroleum based
hydrocarbons having these chain lengths include mineral oil (also
known as "liquid petrolatum") and petrolatum (also known as
"mineral wax," "petroleum jelly" and "mineral jelly"). Mineral oil
usually refers to less viscous mixtures of hydrocarbons having from
16 to 20 carbon atoms. Petrolatum usually refers to more viscous
mixtures of hydrocarbons having from 16 to 32 carbon atoms.
Petrolatum and mineral oil are particularly preferred emollients
for compositions of the present invention.
[0056] Suitable fatty acid ester type emollients include those
derived from C.sub.12-C.sub.28 fatty acids, preferably
C.sub.16-C.sub.22 saturated fatty acids, and short chain
(C.sub.1-C.sub.8, preferably C.sub.1-C.sub.3) monohydric alcohols.
Representative examples of such esters include methyl palmitate,
methyl stearate, isopropyl laurate, isopropyl myristate, isopropyl
palmitate, ethylhexyl palmitate and mixtures thereof. Suitable
fatty acid ester emollients can also be derived from esters of
longer chain fatty alcohols (C.sub.12-C.sub.28, preferably
C.sub.12-C.sub.16) and shorter chain fatty acids e.g., lactic acid,
such as lauryl lactate and cetyl lactate.
[0057] Suitable alkyl ethoxylate type emollients include
C.sub.12-C.sub.22 fatty alcohol ethoxylates having an average
degree of ethoxylation of from about 2 to about 30. Preferably, the
fatty alcohol ethoxylate emollient is selected from the group
consisting of lauryl, cetyl, and stearyl ethoxylates, and mixtures
thereof, having an average degree of ethoxylation ranging from
about 2 to about 23. Representative examples of such alkyl
ethoxylates include laureth-3 (a lauryl ethoxylate having an
average degree of ethoxylation of 3), laureth-23 (a lauryl
ethoxylate having an average degree of ethoxylation of 23),
ceteth-10 (a cetyl alcohol ethoxylate having an average degree of
ethoxylation of 10) and steareth-10 (a stearyl alcohol ethoxylate
having an average degree of ethoxylation of 10). When employed,
these alkyl ethoxylate emollients are typically used in combination
with the petroleum-based emollients, such as petrolatum, at a
weight ratio of alkyl ethoxylate emollient to petroleum-based
emollient of from about 1:1 to about 1:5, preferably from about 1:2
to about 1:4.
[0058] Suitable fatty alcohol type emollients include
C.sub.12-C.sub.22 fatty alcohols, preferably C.sub.16-C.sub.18
fatty alcohols. Representative examples include cetyl alcohol and
stearyl alcohol, and mixtures thereof. When employed, these fatty
alcohol emollients are typically used in combination with the
petroleum-based emollients, such as petrolatum, at a weight ratio
of fatty alcohol emollient to petroleum-based emollient of from
about 1:1 to about 1:5, preferably from about 1:1 to about 1:2.
[0059] Other suitable types of emollients for use herein include
polysiloxane compounds. In general, suitable polysiloxane materials
for use in the present invention include those having monomeric
siloxane units of the following structure: 1
[0060] wherein, R.sup.1 and R.sup.2, for each independent siloxane
monomeric unit can each independently be hydrogen or any alkyl,
aryl, alkenyl, alkaryl, arakyl, cycloalkyl, halogenated
hydrocarbon, or other radical. Any of such radicals can be
substituted or unsubstituted. R.sup.1 and R.sup.2 radicals of any
particular monomeric unit may differ from the corresponding
functionalities of the next adjoining monomeric unit. Additionally,
the polysiloxane can be either a straight chain, a branched chain
or have a cyclic structure. The radicals R.sup.1 and R.sup.2 can
additionally independently be other silaceous functionalities such
as, but not limited to siloxanes, polysiloxanes, silanes, and
polysilanes. The radicals R.sup.1 and R.sup.2 may contain any of a
variety of organic functionalities including, for example, alcohol,
carboxylic acid, phenyl, and amine functionalities.
[0061] Exemplary alkyl radicals are methyl, ethyl, propyl, butyl,
pentyl, hexyl, octyl, decyl, octadecyl, and the like. Exemplary
alkenyl radicals are vinyl, allyl, and the like. Exemplary aryl
radicals are phenyl, diphenyl, naphthyl, and the like. Exemplary
alkaryl radicals are toyl, xylyl, ethylphenyl, and the like.
Exemplary aralkyl radicals are benzyl, alpha-phenylethyl,
beta-phenylethyl, alpha-phenylbutyl, and the like. Exemplary
cycloalkyl radicals are cyclobutyl, cyclopentyl, cyclohexyl, and
the like. Exemplary halogenated hydrocarbon radicals are
chloromethyl, bromoethyl, tetrafluorethyl, fluorethyl,
trifluorethyl, trifluorotloyl, hexafluoroxylyl, and the like.
[0062] Viscosity of polysiloxanes useful may vary as widely as the
viscosity of polysiloxanes in general vary, so long as the
polysiloxane is flowable or can be made to be flowable for
application to the absorbent article. This includes, but is not
limited to, viscosity as low as 5 centistokes (at 37.degree. C. as
measured by a glass viscometer) to about 20,000,000 centistokes.
Preferably the polysiloxanes have a viscosity at 37.degree. C.
ranging from about 5 to about 5,000 centistokes, more preferably
from about 5 to about 2,000 centistokes, most preferably from about
100 to about 1000 centistokes. High viscosity polysiloxanes which
themselves are resistant to flowing can be effectively deposited
upon the absorbent articles by such methods as, for example,
emulsifying the polysiloxane in surfactant or providing the
polysiloxane in solution with the aid of a solvent, such as hexane,
listed for exemplary purposes only. Particular methods for applying
polysiloxane emollients to absorbent articles are discussed in more
detail hereinafter.
[0063] Preferred polysiloxanes compounds for use in the present
invention are disclosed in U.S. Pat. No. 5,059,282 (Ampulski et
al), issued Oct. 22, 1991, which is incorporated herein by
reference. Particularly preferred polysiloxane compounds for use as
emollients in the compositions of the present invention include
phenyl-functional polymethylsiloxane compounds (e.g., Dow Corning
556 Cosmetic-Grade Fluid: polyphenylmethylsiloxane) and cetyl or
stearyl functionalized dimethicones such as Dow 2502 and Dow 2503
polysiloxane liquids, respectively. In addition to such
substitution with phenyl-functional or alkyl groups, effective
substitution may be made with amino, carboxyl, hydroxyl, ether,
polyether, aldehyde, ketone, amide, ester, and thiol groups. Of
these effective substituent groups, the family of groups comprising
phenyl, amino, alkyl, carboxyl, and hydroxyl groups are more
preferred than the others; and phenyl-functional groups are most
preferred.
[0064] Suitable humectants include glycerine, propylene glycol,
sorbitol, trihydroxy stearin, and the like.
[0065] When present, the amount of emollient that can be included
in the composition will depend on a variety of factors, including
the particular emollient involved, the skin benefits desired, the
other components in the composition and like factors. The
composition will comprise from 0 to about 100%, by total weight, of
the emollient. Preferably, the composition will comprise from about
10 to about 95%, more preferably from about 20 to about 80%, and
most preferably from about 40 to about 75%, by weight, of the
emollient.
[0066] Another optional, preferred component of the
therapeutic/skin protective compositions useful in the methods of
the present invention is an agent capable of immobilizing the
composition (including the preferred emollient and/or other skin
condition/protective agents) in the desired location in or on the
treated article. Because certain of the preferred emollients in the
composition have a plastic or liquid consistency at 20.degree. C.,
they tend to flow or migrate, even when subjected to modest shear.
When applied to a wearer-contacting surface or other location of an
absorbent article, especially in a melted or molten state, the
emollient will not remain primarily in or on the treated region.
Instead, the emollient will tend to migrate and flow to undesired
regions of the article.
[0067] Specifically, if the emollient migrates into the interior of
the article, it can cause undesired effects on the absorbency of
the article core due to the hydrophobic characteristics of many of
the emollients and other skin conditioning agents used in the
compositions useful in the methods of the present invention. It
also means that much more emollient has to be applied to the
article to get the desired therapeutic and/or protective benefits.
Increasing the level of emollient not only increases the cost, but
also exacerbates the undesirable effect on the absorbency of the
article's core and undesired transfer of composition during
processing/converting of the treated articles.
[0068] The immobilizing agent counteracts this tendency of the
emollient to migrate or flow by keeping the emollient primarily
localized on the surface or in the region of the article to which
the composition is applied. This is believed to be due, in part, to
the fact that the immobilizing agent raises the melting point
and/or viscosity of the composition above that of the emollient.
Since the immobilizing agent is preferably miscible with the
emollient (or solubilized in the emollient with the aid of an
appropriate emulsifier), it entraps the emollient on the surface of
the article's wearer contacting surface or in the region to which
it is applied.
[0069] The immobilizing agent counteracts this tendency of the
emollient to migrate or flow by keeping the emollient primarily
localized on the surface or in the region of the article to which
the composition is applied. This is believed to be due, in part, to
the fact that the immobilizing agent raises the melting point
and/or viscosity of the composition above that of the emollient.
Since the immobilizing agent is preferably miscible with the
emollient (or solubilized in the emollient with the aid of an
appropriate emulsifier or dispersed therein), it entraps the
emollient on the surface of the article's wearer contacting surface
or in the region to which it is applied.
[0070] It is also advantageous to "lock" the immobilizing agent on
the wearer contacting surface or the region of the article to which
it is applied. This can be accomplished by using immobilizing
agents which quickly set up (i.e., solidify) upon application to
the article. In addition, outside cooling of the treated article
via blowers, fans, cold rolls, etc. can speed up crystallization of
the immobilizing agent.
[0071] In addition to being miscible with (or solubilized in) the
emollient, the immobilizing agent will preferably have a melting
profile that will provide a composition that is solid or semisolid
at ambient temperature. In this regard, preferred immobilizing
agents will have a melting point of at least about 35.degree. C.
This is so the immobilizing agent itself will not have a tendency
to migrate or flow. Preferred immobilizing agents will have melting
points of at least about 40.degree. C. Typically, the immobilizing
agent will have a melting point in the range of from about
50.degree. to about 150.degree. C.
[0072] When utilized, immobilizing agents useful herein can be
selected from any of a number of agents, so long as the preferred
properties of the skin care composition provide the skin benefits
described herein. Preferred immobilizing agents will comprise a
member selected from the group consisting of C.sub.14-C.sub.22
fatty alcohols, C.sub.12-C.sub.22 fatty acids, and
C.sub.12-C.sub.22 fatty alcohol ethoxylates having an average
degree of ethoxylation ranging from 2 to about 30, and mixtures
thereof. Preferred immobilizing agents include C.sub.16-C.sub.18
fatty alcohols, most preferably crystalline high melting materials
selected from the group consisting of cetyl alcohol, stearyl
alcohol, behenyl alcohol, and mixtures thereof. (The linear
structure of these materials can speed up solidification on the
treated absorbent article.) Mixtures of cetyl alcohol and stearyl
alcohol are particularly preferred. Other preferred immobilizing
agents include C.sub.16-C.sub.18 fatty acids, most preferably
selected from the group consisting of palmitic acid, stearic acid,
and mixtures thereof. Mixtures of palmitic acid and stearic acid
are particularly preferred. Still other preferred immobilizing
agents include C.sub.16-C.sub.18 fatty alcohol ethoxylates having
an average degree of ethoxylation ranging from about 5 to about 20.
Preferably, the fatty alcohols, fatty acids and fatty alcohols are
linear. Importantly, these preferred immobilizing agents such as
the C.sub.16-C.sub.18 fatty alcohols increase the rate of
crystallization of the composition causing the composition to
crystallize rapidly onto the surface of the substrate.
[0073] Other types of immobilizing agents that may be used herein
include polyhydroxy fatty acid esters, polyhydroxy fatty acid
amides, and mixtures thereof. Preferred esters and amides will have
three or more free hydroxy groups on the polyhydroxy moiety and are
typically nonionic in character. Because of the possible skin
sensitivity of those using articles to which the composition is
applied, these esters and amides should also be relatively mild and
non-irritating to the skin.
[0074] Suitable polyhydroxy fatty acid esters for use in the
present invention will have the formula: 2
[0075] wherein R is a C.sub.5-C.sub.31 hydrocarbyl group,
preferably straight chain C.sub.7-C.sub.19 alkyl or alkenyl, more
preferably straight chain C.sub.9-C.sub.17 alkyl or alkenyl, most
preferably straight chain C.sub.11-C.sub.17 alkyl or alkenyl, or
mixture thereof, Y is a polyhydroxyhydrocarbyl moiety having a
hydrocarbyl chain with at least 2 free hydroxyls directly connected
to the chain; and n is at least 1. Suitable Y groups can be derived
from polyols such as glycerol, pentaerythritol; sugars such as
raffinose, maltodextrose, galactose, sucrose, glucose, xylose,
fructose, maltose, lactose, mannose and erythrose; sugar alcohols
such as erythritol, xylitol, malitol, mannitol and sorbitol; and
anhydrides of sugar alcohols such as sorbitan.
[0076] One class of suitable polyhydroxy fatty acid esters for use
in the present invention comprises certain sorbitan esters,
preferably the sorbitan esters of C.sub.16-C.sub.22 saturated fatty
acids. Because of the manner in which they are typically
manufactured, these sorbitan esters usually comprise mixtures of
mono-, di-, tri-, etc. esters. Representative examples of suitable
sorbitan esters include sorbitan palmitates (e.g., SPAN 40),
sorbitan stearates (e.g., SPAN 60), and sorbitan behenates, that
comprise one or more of the mono-, di- and tri-ester versions of
these sorbitan esters, e.g., sorbitan mono-, di- and tri-palmitate,
sorbitan mono-, di- and tri-stearate, sorbitan mono-, di and
tri-behenate, as well as mixed tallow fatty acid sorbitan mono-,
di- and tri-esters. Mixtures of different sorbitan esters can also
be used, such as sorbitan palmitates with sorbitan stearates.
Particularly preferred sorbitan esters are the sorbitan stearates,
typically as a mixture of mono-, di- and tri-esters (plus some
tetraester) such as SPAN 60, and sorbitan stearates sold under the
trade name GLYCOMUL-S by Lonza, Inc. Although these sorbitan esters
typically contain mixtures of mono-, di- and tri-esters, plus some
tetraester, the mono- and di-esters are usually the predominant
species in these mixtures.
[0077] Another class of suitable polyhydroxy fatty acid esters for
use in the present invention comprises certain glyceryl monoesters,
preferably glyceryl monoesters of C.sub.16-C.sub.22 saturated fatty
acids such as glyceryl monostearate, glyceryl monopalmitate, and
glyceryl monobehenate. Again, like the sorbitan esters, glyceryl
monoester mixtures will typically contain some di- and triester.
However, such mixtures should contain predominantly the glyceryl
monoester species to be useful in the present invention.
[0078] Another class of suitable polyhydroxy fatty acid esters for
use in the present invention comprise certain sucrose fatty acid
esters, preferably the C.sub.12-C.sub.22 saturated fatty acid
esters of sucrose. Sucrose monoesters and diesters are particularly
preferred and include sucrose mono- and di-stearate and sucrose
mono- and di- laurate.
[0079] Suitable polyhydroxy fatty acid amides for use in the
present invention will have the formula: 3
[0080] wherein R.sup.1 is H, C.sub.1-C.sub.4 hydrocarbyl,
2-hydroxyethyl, 2-hydroxypropyl, methoxyethyl, methoxypropyl or a
mixture thereof, preferably C.sub.1-C.sub.4 alkyl, methoxyethyl or
methoxypropyl, more preferably C.sub.1 or C.sub.2 alkyl or
methoxypropyl, most preferably C.sub.1 alkyl (i.e., methyl) or
methoxypropyl; and R.sup.2 is a C.sub.5-C.sub.31 hydrocarbyl group,
preferably straight chain C.sub.7-C.sub.19 alkyl or alkenyl, more
preferably straight chain C.sub.9-C.sub.17 alkyl or alkenyl, most
preferably straight chain C.sub.11-C.sub.17 alkyl or alkenyl, or
mixture thereof, and Z is a polyhydroxyhydrocarbyl moiety having a
linear hydrocarbyl chain with at least 3 hydroxyls directly
connected to the chain. See U.S. Pat. No. 5,174, 927 (Honsa),
issued Dec. 29, 1992 (herein incorporated by reference) which
discloses these polyhydroxy fatty acid amides, as well as their
preparation.
[0081] The Z moiety preferably will be derived from a reducing
sugar in a reductive anination reaction; most preferably glycityl.
Suitable reducing sugars include glucose, fructose, maltose,
lactose, galactose, mannose, and xylose. High dextrose corn syrup,
high fructose corn syrup, and high maltose corn syrup can be
utilized, as well as the individual sugars listed above. These corn
syrups can yield mixtures of sugar components for the Z moiety.
[0082] The Z moiety preferably will be selected from the group
consisting of --CH.sub.2--(CHOH).sub.n--CH.sub.2OH,
--CH(CH.sub.2OH)-[(CHOH).sub.n-1- ]--CH.sub.2OH,
--CH.sub.2OH--CH.sub.2--(CHOH).sub.2(CHOR.sup.3)(CHOH)--CH.-
sub.2OH, where n is an integer from 3 to 5, and R.sup.3 is H or a
cyclic or aliphatic monosaccharide. Most preferred are the
glycityls where n is 4, particularly
--CH.sub.2--(CHOH).sub.4--CH.sub.2OH.
[0083] In the above formula, R.sup.1 can be, for exanple, N-methyl,
N-ethyl, N-propyl, N-isopropyl, N-butyl, N-2-hydroxyethyl,
N-methoxypropyl or N-2-hydroxypropyl. R.sup.2 can be selected to
provide, for example, cocamides, stearamides, oleamides,
lauramides, myristamides, capricanides, palmitamides, tallowamides,
etc. The Z moiety can be 1-deoxyglucityl, 2-deoxyfructityl,
1-deoxymaltityl, 1-deoxylactityl, 1-deoxygalactityl,
1-deoxymannityl, 1-deoxymaltotriotityl, etc.
[0084] The most preferred polyhydroxy fatty acid amides have the
general formula: 4
[0085] wherein R.sup.1 is methyl or methoxypropyl; R.sup.2 is a
C.sub.11-C.sub.17 straight-chain alkyl or alkenyl group. These
include N-lauryl-N-methyl glucamide, N-lauryl-N-methoxypropyl
glucamide, N-cocoyl-N-methyl glucamide, N-cocoyl-N-methoxypropyl
glucamide, N-palmityl-N-methoxypropyl glucamide,
N-tallowyl-N-methyl glucamide, or N-tallowyl-N-methoxypropyl
glucamide.
[0086] As previously noted, some of the immobilizing agents may
require an emulsifier for solubilization in the emollient. This is
particularly the case for certain of the glucamides such as the
N-alkyl-N-methoxypropyl glucamides having HLB values of at least
about 7. Suitable emulsifiers will typically include those having
HLB values below about 7. In this regard, the sorbitan esters
previously described, such as the sorbitan stearates, having HLB
values of about 4.9 or less have been found useful in solubilizing
these glucamide immobilizing agents in petrolatum. Other suitable
emulsifiers include steareth-2 (polyethylene glycol ethers of
stearyl alcohol that conform to the formula
CH.sub.3(CH.sub.2).sub.17(OCH- .sub.2CH.sub.2).sub.nOH, where n has
an average value of 2), sorbitan tristearate, isosorbide laurate,
and glyceryl monostearate. The emulsifier can be included in an
amount sufficient to solubilize the immobilizing agent in the
emollient such that a substantially homogeneous mixture is
obtained. For example, an approximately 1:1 mixture of
N-cocoyl-N-methyl glucamide and petrolatum that will normally not
melt into a single phase mixture, will melt into a single phase
mixture upon the addition of 20% of a 1:1 mixture of Steareth-2 and
sorbitan tristearate as the emulsifier.
[0087] Other types of ingredients that can be used as immobilizing
agents, either alone, or in combination with the above-mentioned
immobilizing agents, include waxes such as carnauba, ozokerite,
beeswax, candelilla, paraffin, ceresin, esparto, ouricuri, rezowax,
isoparaffin, and other known mined and mineral waxes. The high melt
point of these materials can help immobilize the composition on the
desired surface or location on the article. Addionally
microcrystalline waxes are effective immobilizing agents.
Microcrystalline waxes can aid in "locking" up low molecular weight
hydrocarbons within the skin care composition. Preferably the wax
is a paraffin wax. An example of a particularly preferred alternate
immobilizing agent is a paraffin wax such as Parrafin S.P. 434 from
Strahl and Pitsch Inc. P.O. Box 1098 West Babylon, N.Y. 11704.
[0088] The amount of the optional immobilizing agent that can be
included in the composition will depend on a variety of factors,
including the actives (e.g., emollients) involved, the particular
immobilizing agent involved, if any, the other components in the
composition, whether an emulsifier is required to solubilize the
immobilizing agent in the other components, and like factors. When
present, the composition will typically comprise from about 5 to
about 90% of the immobilizing agent. Preferably, the composition
will comprise from about 5 to about 50%, most preferably from about
10 to about 40%, of the immobilizing agent.
[0089] Of course, it is highly desirable that at least a portion of
the article's topsheet be made of a hydrophilic material to promote
rapid transfer of liquids (e.g., urine) through the topsheet.
Similarly, it may be desirable that the composition be sufficiently
wettable to ensure that liquids will transfer through the topsheet
rapidly. Alternatively, hydrophobic skin care composition may be
utilized, so long as they are applied such that the fluid handling
properties of the topsheet are adequately maintained. (For example,
as discussed below, nonuniform application of the composition to
the topsheet is one means to accomplish this goal.) This diminishes
the likelihood that body exudates will flow off the
composition-treated topsheet rather than being drawn through the
topsheet and being absorbed by the absorbent core. Where a
hydrophilic composition is desired, depending upon the particular
components used in the composition, a hydrophilic surfactant (or a
mixture of hydrophilic surfactants) may, or may not, be required to
improve wettability. For example, some immobilizing agents, such as
N-cocoyl-N-methoxypropyl glucamide have HLB values of at least
about 7 and are sufficiently wettable without the addition of
hydrophilic surfactant. Other immobilizing agents such as the
C.sub.16- Clg fatty alcohols having HLB values below about 7 may
require addition of hydrophilic surfactant to improve wettability
when the composition is applied to article topsheets. Similarly, a
hydrophobic emollient such as petrolatum may require the addition
of a hydrophilic surfactant if hydrophilic composition is desired.
Of course, the concern around wettability is not a factor when the
wearer-contacting surface under consideration is other than the
article's topsheet or when fluid handling properties of the
topsheet are adequately maintained via other means (e.g.,
nonuniform application).
[0090] Suitable hydrophilic surfactants will preferably be miscible
with the other components of the skin care composition so as to
form blended mixtures. Because of possible skin sensitivity of
those using disposable absorbent products to which the composition
is applied, these surfactants should also be relatively mild and
non-irritating to the skin. Typically, these hydrophilic
surfactants are nonionic to be not only non-irritating to the skin,
but also to avoid other undesirable effects on any other structures
within the treated article. For example, reductions tissue laminate
tensile strength, adhesive bond sufficiencies, and the like.
[0091] Suitable nonionic surfactants may be substantially
nonmigratory after the composition is applied to the articles and
will typically have HLB values in the range of from about 4 to
about 20, preferably from about 7 to about 20. To be nonmigratory,
these nonionic surfactants will typically have melt temperatures
greater than the temperatures commonly encountered during storage,
shipping, merchandising, and use of disposable absorbent products,
e.g., at least about 30.degree. C. In this regard, these nonionic
surfactants will preferably have melting points similar to those of
the immobilizing agents previously described.
[0092] Suitable nonionic surfactants for use in compositions that
will be applied to the articles, at least in the liquid discharge
region of the diaper, include alkylglycosides; alkylglycoside
ethers as described in U.S. Pat. No. 4,011,389 (Langdon, et al),
issued Mar. 8, 1977, which is incorporated by reference;
alkylpolyethoxylated esters such as Pegosperse 1000MS (available
from Lonza, Inc., Fair Lawn, N.J.), ethoxylated sorbitan mono-, di-
and/or tri-esters of C.sub.12-C.sub.18 fatty acids having an
average degree of ethoxylation of from about 2 to about 20,
preferably from about 2 to about 10, such as TWEEN 60 (sorbitan
esters of stearic acid having an average degree of ethoxylation of
about 20) and TWEEN 61 (sorbitan esters of stearic acid having an
average degree of ethoxylation of about 4), and the condensation
products of aliphatic alcohols with from about 1 to about 54 moles
of ethylene oxide. The alkyl chain of the aliphatic alcohol is
typically in a straight chain (linear) configuration and contains
from about 8 to about 22 carbon atoms. Particularly preferred are
the condensation products of alcohols having an alkyl group
containing from about 11 to about 22 carbon atoms with from about 2
to about 30 moles of ethylene oxide per mole of alcohol. Examples
of such ethoxylated alcohols include the condensation products of
myristyl alcohol with 7 moles of ethylene oxide per mole of
alcohol, the condensation products of coconut alcohol (a mixture of
fatty alcohols having alkyl chains varying in length from 10 to 14
carbon atoms) with about 6 moles of ethylene oxide. A number of
suitable ethoxylated alcohols are commercially available, including
TERGITOL 15-S-9 (the condensation product of C.sub.11-C.sub.15
linear alcohols with 9 moles of ethylene oxide), marketed by Union
Carbide Corporation; KYRO EOB (condensation product of
C.sub.13-C.sub.15 linear alcohols with 9 moles of ethylene oxide),
marketed by The Procter & Gamble Co., the NEODOL brand name
surfactants marketed by Shell Chemical Co., in particular NEODOL
25-12 (condensation product of C.sub.12-C.sub.15 linear alcohols
with 12 moles of ethylene oxide) and NEODOL 23-6.5T (condensation
product of C.sub.12-C.sub.13 linear alcohols with 6.5 moles of
ethylene oxide that has been distilled (topped) to remove certain
impurities), and especially the PLURAFAC brand name surfactants
marketed by BASF Corp., in particular PLURAFAC A-38 (a condensation
product of a C.sub.18 straight chain alcohol with 27 moles of
ethylene oxide). (Certain of the hydrophilic surfactants, in
particular ethoxylated alcohols such as NEODOL 25-12, can also
function as alkyl ethoxylate emollients). Other examples of
preferred ethoxylated alcohol surfactants include ICI's class of
Brij surfactants and mixtures thereof, with Brij 72 (i.e.,
Steareth-2) and Brij 76 (i.e., Steareth-10) being especially
preferred. Also, mixtures of cetyl alcohol and stearyl alcohol
ethoxylated to an average degree of ethoxylation of from about 10
to about 20 may also be used as the hydrophilic surfactant.
[0093] Another type of suitable surfactant for use in the
composition includes Aerosol OT, a dioctyl ester of sodium
sulfosuccinic acid marketed by American Cyanamid Company.
[0094] Still another type of suitable surfactant for use in the
composition includes silicone copolymers such as General Electric
SF 1188 (a copolymer of a polydimethylsiloxane and a
polyoxyalkylene ether) and General Electric SF 1228 (a silicone
polyether copolymer). These silicone surfactants can be used in
combination with the other types of hydrophilic surfactants
discussed above, such as the ethoxylated alcohols. These silicone
surfactants have been found to be effective at concentrations as
low as 0.1%, more preferably from about 0.25 to about 1.0%, by
weight of the composition.
[0095] Where a hydrophilic composition is desired, the amount of
hydrophilic surfactant required to increase the wettability of the
composition to a desired level will depend in-part upon the HLB
value and level of immobilizing agent, if any, used, the HLB value
of the surfactant used and like factors. The composition can
comprise from about 0.1 to about 50% of the hydrophilic surfactant
when needed to increase the wettability properties of the
composition. Preferably, the composition comprises from about 1 to
about 25%, most preferably from about 10 to about 20%, of the
hydrophilic surfactant when needed to increase wettability.
[0096] Compositions can comprise other components typically present
in emulsions, creams, ointment, lotions, powders, suspensions, etc.
of this type. These components include water, viscosity modifiers,
perfumes, disinfectant antibacterial actives, antiviral agents,
vitamins, pharmaceutical actives, film formers, deodorants,
opacifiers, astringents, solvents, preservatives, and the like. In
addition, stabilizers can be added to enhance the shelf life of the
composition such as cellulose derivatives, proteins and lecithin.
All of these materials are well known in the art as additives for
such formulations and can be employed in appropriate amounts in the
compositions for use herein.
[0097] If water-based skin care compositions are used, a
preservative will be needed. Suitable preservatives include propyl
paraben, methyl paraben, benzyl alcohol, benzylkonnium, tribasic
calcium phosphate, BHT, or acids such as citric, tartaric, maleic,
lactic, malic, benzoic, salicylic, and the like. Suitable viscosity
increasing agents include some of the agents described as effective
immobilizing agents. Other suitable viscosity increasing agents
include alkyl galactomannan, silica, talc, magnesium silicate,
sorbitol, colloidal silicone dioxide, magnesium aluminum silicate,
zinc stearate, wool wax alcohol, sorbiton, sesquioleate, cetyl
hydroxy ethyl cellulose and other modified celluloses. Suitable
solvents include propylene glycol, glycerine, cyclomethicone,
polyethylene glycols, hexalene glycol, diol and multi-hydroxy based
solvents. Suitable vitamins include A, D-3, E, B-5 and E
acetate.
[0098] IV. Absorbent Articles
[0099] As used herein, the term "absorbent article" refers to a
device which absorbs and retains body exudates. The term
"disposable" is used herein to describe absorbent articles which
are not intended to be laundered or otherwise restored or reused as
an absorbent article after a single use. Examples of disposable
absorbent articles include feminine hygiene garments such as
sanitary napkins, panti-liners and tampons, diapers, incontinence
briefs, diaper holders, training pants, and the like.
[0100] Disposable absorbent articles typically comprise a liquid
pervious topsheet, a liquid impervious backsheet and an absorbent
core positioned between the topsheet and the backsheet. Disposable
absorbent articles and components thereof, including the topsheet,
backsheet, absorbent core, and any individual layers of these
components, have a body facing surface and a garment facing
surface. As used herein, "body facing surface" means that surface
of the article or component which is intended to be worn toward or
adjacent to the body of the wearer, while the "garment facing
surface" is on the opposite side and is intended to be worn toward
or placed adjacent to the wearer's clothing or undergarments when
the disposable absorbent article is worn.
[0101] The following description generally discusses the absorbent
core, topsheet, and backsheet materials that are useful in
disposable absorbent articles that are used in the methods of the
present invention. It is to be understood that this general
description applies to these components of the specific absorbent
articles shown in FIG. 1 and further described below, in addition
to those of other disposable absorbent articles which are generally
described herein.
[0102] In general, the absorbent core is capable of absorbing or
retaining liquids (e.g., menses, urine, and/or other body
exudates). The absorbent core is preferably compressible,
conformable, and non-irritating to the wearer's skin. The absorbent
core may be manufactured in a wide variety of sizes and shapes
(e.g., rectangular, oval, hourglass, "T" shaped, dog bone,
asymmetric, etc.). In addition to the absorbent composites of the
present invention, the absorbent core may include any of a wide
variety of liquid-absorbent materials commonly used in absorbent
articles, such as comminuted wood pulp, which is generally referred
to as airfelt. Examples of other suitable absorbent materials for
use in the absorbent core include creped cellulose wadding;
meltblown polymers including coform; chemically stiffened, modified
or cross-linked cellulosic fibers; synthetic fibers such as crimped
polyester fibers; peat moss; tissue including tissue wraps and
tissue laminates; absorbent foams; absorbent sponges;
superabsorbent polymers; absorbent gelling materials; or any
equivalent material or combinations of materials, or mixtures of
these.
[0103] The configuration and construction of the absorbent core may
also be varied (e.g., the absorbent core may have varying caliper
zones and/or have a profile so as to be thicker in the center;
hydrophilic gradients; gradients of the absorbent composite of the
present invention, superabsorbent gradients; or lower average
density and lower average basis weight zones, e.g., acquisition
zones; or may comprise one or more layers or structures). The total
absorbent capacity of the absorbent core should, however, be
compatible with the design loading and the intended use of the
absorbent article. Further, the size and absorbent capacity of the
absorbent core may be varied to accommodate different uses such as
diapers, incontinence pads, pantiliners, regular sanitary napkins,
and overnight sanitary napkins, and to accommodate wearers ranging
from infants to adults.
[0104] The absorbent core can include other absorbent components
that are often used in absorbent articles, for example, a dusting
layer, a wicking or acquisition layer, or a secondary topsheet for
increasing the wearer's comfort.
[0105] The topsheet is preferably compliant, soft feeling, and
non-irritating to the wearer's skin. Further, the topsheet is
liquid pervious, permitting liquids (e.g., menses and/or urine) to
readily penetrate through its thickness. A suitable topsheet may be
manufactured from a wide range of materials such as woven and
nonwoven materials (e.g., a nonwoven web of fibers), including
apertured nonwovens; polymeric materials such as apertured formed
thermoplastic films, apertured plastic films, and hydroformed
thermoplastic films; porous foans; reticulated foams; reticulated
thermoplastic films; and thermoplastic scrims. Suitable woven and
nonwoven materials can be comprised of natural fibers (e.g., wood
or cotton fibers), synthetic fibers (e.g., polymeric fibers such as
polyester, polypropylene, or polyethylene fibers) or from a
combination of natural and synthetic fibers. When the topsheet
comprises a nonwoven web, the web may be manufactured by a wide
number of known techniques. For example, the web may be spunbonded,
spunlace carded, wet-laid, melt-blown, hydroentangled, hydroformed,
hydroapertured, combinations of the above, or the like.
[0106] The backsheet is impervious to liquids (e.g., menses and/or
urine) and is preferably comprises a thin plastic film, although
other flexible liquid impervious materials may also be used. As
used herein, the term "flexible" refers to materials which are
compliant and will readily conform to the general shape and
contours of the human body. The backsheet prevents the exudates
absorbed and contained in the absorbent core from wetting articles
which contact the absorbent article such as bedsheets, pants,
pajamas and undergarments. The backsheet may thus comprise a woven
or nonwoven material, polymeric films such as thermoplastic films
of polyethylene or polypropylene, or composite materials such as a
film-coated nonwoven material.
[0107] The backing materials or outer covers of diapers have
traditionally been made from plastic films due to cost
considerations and the liquid impermeable nature of plastic films.
While plastic films are efficient at containing liquids and other
waste matters durig use, the same plastic films have certain
disadvantages in that they are not pleasing to the touch and they
do not readily pass water vapor so that, from a wearer wellness
standpoint, plastic films tend to cause skin hydration thereby
making infants more prone to diaper rash. One solution has been to
supplant normal nonporous plastic films with breathable plastic
films as the diaper backing materials. For the purposes of the
present invention, a film is "breathable" if it has a water vapor
transmission rate of at least 100 g/m.sup.2/24 hours as calculated
using the test method outlined below with respect to the examples.
Polyolefin films are often used for making breathable films. A
particularly useful film for such application is made from a linear
polyolefin containing organic and/or inorganic fillers. Such filled
polyolefin films provide good water vapor transmission therby
making the diapers more comfortable to the wearer. As a result, the
relative humidity and temperature within the diaper or other
product can be reduced by using breathable materials. Despite this,
such breathable films have the disadvantage of being cold and
clammy because breathable films pass moisture to the outside of the
product where it condenses readily on the film surface.
Consequently, another solution has been to attempt to use nonwoven
materials as the backing material for diapers. Fibrous nonwoven
webs when used as the backing material for diapers alleviate the
above-mentioned film problems, however, such fibrous nonwoven webs
generally provide poor barriers to the passage of liquids including
urine. In view of the foregoing deficiencies of both films and
fibrous nonwovens, attempts have been made to combine the two
materials thereby making it possible to rely upon the strengths of
one material to overcome the weaknesses of the other.
[0108] A suitable backsheet is a polyethylene film having a
thickness of from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0
mils). Exemplary polyethylene films are manufactured by Clopay
Corporation of Cincinnati, Ohio, under the designation P18-1401 and
by Tredegar Film Products of Terre Haute, Ind., under the
designation XP-39385. The backsheet is preferably embossed and/or
matte finished to provide a more clothlike appearance. The size of
the backsheet is dictated by the size of the absorbent core and the
exact absorbent article design selected.
[0109] As discussed above, while it is preferred that the
composition which is continually, automatically transferred to the
wearer's skin by wearing articles described herein be relatively
impervious to liquids such as urine and runny feces, it is also
preferred that the composition be relatively vapor pervious to
provide a nonocclusive barrier for the skin. In this regard, to
further facilitate the maintenance or improvement of skin health,
uncompromised skin in the wearer's region under the absorbent
article via the presently disclosed methods, preferred absorbent
articles useful in those methods are those which also provide
"breathability", to facilitate relatively lower relative humidity
in the area between the skin and the absorbent article. Recently,
attempts have been disclosed that are directed to improving wearer
skin condition by allowing the overhydrated skin to dehydrate to an
acceptable level by allowing either air to reach the skin (thus
minimizing potential occlusion effects) and/or providing means for
removing water vapor from the surface of the skin. Generally, such
mechanisms are referred to as "breathability" or "vapor or moisture
permeability". Specific examples include feminine hygiene products,
such as catamenial products or so-called pantiliners as described
in EP-A-0.104.906; EP-A-0.171.041; EP-A-0.710.471; the disclosure
of each of which is incorporated herein by reference. Such products
generally have relatively low liquid storage capacity when
compared, for example, to baby diapers or adult incontinence
products, which have theoretical storage capacities more than ten
times the capacity of a feminine hygiene product. The "breathable"
articles described in these references may be treated with skin
care composition as described herein, and such treated articles may
be useful in the methods of the present invention.
[0110] Such breathable materials can be various kinds of webs, such
as films which are rendered air/vapor pervious by aperturing as
described in U.S. Pat. No. 5,628,737, which issued in the name of
Dobrin, et al. on May 13, 1997, or by exploiting the
"microporosity" property as described in EP-A-0.238.200;
EP-A-0.288.021; EP-A-0.352.802; EP-A-0.515.501; U.S. Pat. No.
4.713.068, whereby small voids are created within the film similar
to very small cracks. WO 94/23107; WO 94/28224; U.S. Pat. No.
4,758,339 which issued in the name of Yeo, et al. on Jul. 19, 1988;
and EP-A-0.315.013 all describe alternative breathable materials
which can be fibrous textile or non-woven webs, with air/vapor
easily penetrating through the relatively large pores of the
structure. Such webs, being either treated or untreated with regard
to improving their liquid impermeability properties, such as
described in EP-A-0.196.654. In WO 95/16562 a laminate of a
non-woven with a breathable film is disclosed. Further disclosures
such as in WO 95/16746 relate to other materials allowing water
molecules to diffuse through. Also, combinations of various
materials comprising various layers of any of the above elements
are also well known. Absorbent articles using any of the approaches
described in these references (each of which is incorporated herein
by reference) in combination with delivering a composition as
described herein may be used to carry out the methods of the
present invention. Indeed, a particularly preferred absorbent
article for use in the present methods is described in detail in
U.S. Pat. No. 6,107,537, issued to Elder et al. on Aug. 22, 2000,
the disclosure of which is incorporated herein by reference.
[0111] The backsheet and the topsheet are positioned adjacent the
garment facing surface and the body facing surface, respectively,
of the absorbent core. The absorbent core is preferably joined with
the topsheet, the backsheet, or both in any manner as is known by
attachment means (not shown in FIG. 1) such as those well known in
the art. However, embodiments of the present invention are
envisioned wherein portions or the entire absorbent core are
unattached to either the topsheet, the backsheet, or both.
[0112] For example, the backsheet and/or the topsheet may be
secured to the absorbent core or to each other by a uniform
continuous layer of adhesive, a patterned layer of adhesive, or an
array of separate lines, spirals, or spots of adhesive. Adhesives
which have been found to be satisfactory are manufactured by H. B.
Fuller Company of St. Paul, Minn. under the designation HL-1258 or
H-2031. The attachment means will preferably comprise an open
pattern network of filaments of adhesive as is disclosed in U.S.
Pat. No. 4,573,986, issued to Minetola, et al. on Ma. 4, 1986, and
which is incorporated herein by reference. An exemplary attachment
means of an open pattern network of filaments comprises several
lines of adhesive filaments swirled into a spiral pattern such as
illustrated by the apparatus and method shown in U.S. Pat. No.
3,911,173 issued to Sprague, Jr. on Oct. 7, 1975; U.S. Pat. No.
4,785,996 issued to Zwieker, et al. on Nov. 22, 1978; and U.S. Pat.
No. 4,842,666 issued to Werenicz on Jun. 27, 1989. Each of these
patents are incorporated herein by reference. Alternatively, the
attachment means may comprise heat bonds, pressure bonds,
ultrasonic bonds, dynamic mechanical bonds, or any other suitable
attachment means or combinations of these attachment means as are
known in the art.
[0113] A preferred disposable absorbent article in which the wearer
contacting surface is treated with a composition are diapers. As
used herein, the term "diaper" refers to an absorbent article
generally worn by infants, and incontinent persons, that is worn
about the lower torso of the wearer. In other words, the term
"diaper" includes infant diapers, training pants, adult
incontinence devices, etc.
[0114] FIG. 1 is a plan view of the diaper 50 useful in the methods
of the present invention in its flat-out, uncontracted state (i.e.,
with elastic induced contraction pulled out) with portions of the
structure being cut-away to more clearly show the construction of
the diaper 50 and with the portion of the diaper 50 which faces
away from the wearer (the outer surface) oriented towards the
viewer. As shown in FIG. 1, the diaper 50 preferably comprises a
liquid pervious topsheet 520; a liquid impervious backsheet 530
joined with the topsheet 520; an absorbent core 540 positioned
between the topsheet 520 and the backsheet 530, the absorbent core
540 having a garment facing surface 542, a body facing surface 544,
side edges 546, waist edges 548, and ears 549. The diaper 50
preferably further comprises elasticized leg cuffs 550; an elastic
waist feature multiply designated as 560; and a fastening system
generally multiply designated as 570.
[0115] The diaper 50 is shown in FIG. 1 to have an outer surface
52, an inner surface 54 corresponding to the body facing surface
which is opposed to the outer surface 52, a first waist region 56,
a second waist region 58, and a periphery 51 which is defined by
the outer edges of the diaper 50 in which the longitudinal edges
are designated 55 and the end edges are designated 57. (While the
skilled artisan will recognize that a diaper is usually described
in terms of having a pair of waist regions and a crotch region
between the waist regions, in this application, for simplicity of
terminology, the diaper 50 is described as having only waist
regions including a portion of the diaper which would typically be
designated as part of the crotch region). The body facing surface
54 of the diaper 50 comprises that portion of the diaper 50 which
is positioned adjacent to the wearer's body during use. The body
facing surface 54 generally is formed by at least a portion of the
topsheet 520 and other components that may be joined to the
topsheet 520, such as leg cuffs 550, as well as any regions to
which the topsheet may not extend but which still contact the
wearer, such as the waist feature 560, side panels and the like.
The outer surface 52 comprises that portion of the diaper 50 which
is positioned away from the wearer's body (i.e., the outer surface
52 generally is formed by at least a portion of the backsheet 530
and other components that may be joined to the backsheet 530). The
first waist region 56 and the second waist region 58 extend,
respectively, from the end edges 57 of the periphery 51 to the
lateral centerline 53 of the diaper 50. FIG. 1 also shows the
longitudinal centerline 59.
[0116] FIG. 1 shows a preferred embodiment of the diaper 50 in
which the topsheet 520 and the backsheet 530 have length and width
dimensions generally larger than those of the absorbent core 540.
The elasticized leg cuffs 550 and the backsheet 530 extend beyond
the edges of the absorbent core 540 to thereby form the periphery
51 of the diaper 50.
[0117] Diapers of the present invention can have a number of well
known configurations, with the absorbent cores thereof being
adapted to the present invention. Exemplary configurations are
described generally in U.S. Pat. No. 3,860,003 issued to Buell on
Jan. 14, 1975; U.S. Pat. No. 5,151,092 issued to Buell et al. on
Sep. 29, 1992; U.S. Pat. No. 5,221,274 issued to Buell et al. on
Jun. 22, 1993. Each of these patents is incorporated herein by
reference. Another diaper configuration to which the present
invention can be readily adapted are described in co-pending U.S.
patent application Ser. Nos. 08/203,456; filed on Feb. 28, 1994 and
incorporated herein by reference. The absorbent cores of diapers
described in these patents can be adapted in light of the teachings
herein to include the absorbent composite of the present invention
as an absorbent gelling material described therein.
[0118] A topsheet 520 which is particularly suitable for use in the
diaper 50, is carded and thermally bonded by means well known to
those skilled in the fabrics art. A satisfactory topsheet for the
present invention comprises staple length polypropylene fibers
having a denier of about 2.2 As used herein, the term "staple
length fibers" refers to those fibers having a length of at least
about 15.9 mm (0.625 inches). Preferably, the topsheet has a basis
weight from about 14 to about 25 grams per square meter. A suitable
topsheet is manufactured by Veratec, Inc., a Division of
International Paper Company, of Walpole, Mass. under the
designation P-8.
[0119] The topsheet 520 of diaper 50 is preferably made of a
hydrophilic material to promote rapid transfer of liquids (e.g.,
urine) through the topsheet. If the topsheet is made of a
hydrophobic material, at least portions of the upper surface of the
topsheet are treated to be hydrophilic so that liquids will
transfer through the topsheet more rapidly. This diminishes the
likelihood that body exudates will flow off the topsheet rather
than being drawn through the topsheet and being absorbed by the
absorbent core. The topsheet can be rendered hydrophilic by
treating it with a surfactant. Suitable methods for treating the
topsheet with a surfactant include spraying the topsheet material
with the surfactant and immersing the material into the surfactant.
A more detailed discussion of such a treatment and hydrophilicity
is contained in U.S. Pat. Nos. 4,988,344 entitled "Absorbent
Articles with Multiple Layer Absorbent Layers" issued to Reising,
et al on Jan. 29, 1991 and U.S. Pat. No. 4,988,345 entitled
"Absorbent Articles with Rapid Acquiring Absorbent Cores" issued to
Reising on Jan. 29, 1991, each of which is incorporated by
reference herein.
[0120] Alternatively, the topsheet may be in the form of an
apertured formed film, which is preferred in feminine hygiene
absorbent articles. Apertured formed films are useful because they
are pervious to body liquids and yet non-absorbent and have a
reduced tendency to allow liquids to pass back through and rewet
the wearer's skin. Thus, the surface of the formed film that is in
contact with the body remains dry, thereby reducing body soiling
and creating a more comfortable feel for the wearer. Suitable
formed films are described in U.S. Pat. No. 3,929,135 (Thompson),
issued Dec. 30, 1975; U.S. Pat. No. 4,324,246 (Mullane et al.),
issued Apr. 13, 1982; U.S. Pat. No. 4,342,314 (Radel. et al.),
issued Aug. 3, 1982; U.S. Pat. No. 4,463,045 (Ahr et al.), issued
Jul. 31, 1984; and U.S. Pat. No. 5,006,394 (Baird), issued Apr. 9,
1991. Each of these patents are incorporated herein by reference.
Particularly preferred microapertured formed film topsheets are
disclosed in U.S. Pat. No. 4,609,518 (Curro et al), issue Sep. 2,
1986 and U.S. Pat. No. 4,629,643 (Curro et al), issued Dec. 16,
1986, which are incorporated by reference. The preferred topsheet
for use in feminine hygiene products is the formed film described
in one or more of the above patents and marketed on sanitary
napkins by The Procter & Gamble Company of Cincinnati, Ohio as
"DRI-WEAVE.RTM.."
[0121] The body facing surface of the formed film topsheet can be
hydrophilic so as to help body liquids to transfer through the
topsheet faster than if the body surface was not hydrophilic so as
to diminish the likelihood that liquid will flow off the topsheet
rather than flowing into and being absorbed by the absorbent
structure. In a preferred embodiment, surfactant is incorporated
into the polymeric materials of the formed film topsheet such as is
described in U.S. patent application Ser. No. 07/794,745,
"Absorbent Article Having A Nonwoven and Apertured Film Coversheet"
filed on Nov. 19, 1991 by Aziz, et al., which is incorporated by
reference. Alternatively, the body facing surface of the topsheet
can be made hydrophilic by treating it with a surfactant such as is
described in the above referenced U.S. Pat. No. 4,950,254,
incorporated herein by reference.
[0122] In a preferred embodiment of a diaper as described herein,
the backsheet 530 has a modified hourglass shape extending beyond
the absorbent core a minimum distance of about 1.3 cm to about 6.4
cm (about 0.5 to about 2.5 inch) around the entire diaper
periphery.
[0123] The absorbent core 540 may take on any size or shape that is
compatible with the diaper 50. One preferred embodiment of the
diaper 50 has an asymmetric, modified T-shaped absorbent core 540
having ears in the first waist region but a generally rectangular
shape in the second waist region. Exemplary absorbent materials for
use as the absorbent core of articles useful in the present methods
are described, e.g., in U.S. Pat. No. 4,610,678 entitled
"High-Density Absorbent Structures" issued to Weisman et al. on
Sep. 9, 1986; U.S. Pat. No. 4,673,402 entitled "Absorbent Articles
With Dual-Layered Cores" issued to Weisman et al. on Jun. 16, 1987;
U.S. Pat. No. 4,888,231 entitled "Absorbent Core Having A Dusting
Layer" issued to Angstadt on Dec. 19, 1989; and U.S. Pat. No.
4,834,735, entitled "High Density Absorbent Members Having Lower
Density and Lower Basis Weight Acquisition Zones", issued to
Alemany et al. on May 30, 1989. The absorbent core may further
comprise the dual core system containing an
acquisition/distribution core of chemically stiffened fibers
positioned over an absorbent storage core as detailed in U.S. Pat.
No. 5,234,423, entitled "Absorbent Article With Elastic Waist
Feature and Enhanced Absorbency" issued to Alemany et al., on Aug.
10, 1993; and in U.S. Pat. No. 5,147,345, entitled "High Efficiency
Absorbent Articles For Incontinence Management" issued to Young,
LaVon and Taylor on Sep. 15, 1992. All of these patents are
incorporated herein by reference.
[0124] In a preferred embodiment, the diaper 50 further comprises
elasticized leg cuffs 550 for providing improved containment of
liquids and other body exudates; an elastic waist feature 560 that
provides improved fit and containment; and a fastening system 570
which forms a side closure which maintains the first waist region
56 and the second waist region 58 in an overlapping configuration
such that lateral tensions are maintained around the circumference
of the diaper to maintain the diaper on the wearer. The diaper 50
may also comprise elasticized waist bands (not shown) and/or
elasticized side panels (also not shown) in the waist regions 56
and 58 to provide an elastically extensible feature that provides a
more comfortable and contouring fit and more effective application
of the diaper 50.
[0125] The elasticized leg cuffs 550 can be constructed in a number
of different configurations, including those described in U.S. Pat.
No. 3,860,003; U.S. Pat. No. 4,909,803, issued to Aziz et al. on
Mar. 20, 1990; U.S. Pat. No. 4,695,278, issued to Lawson on Sep.
22, 1987; and U.S. Pat. No. 4,795,454, issued to Dragoo on Jan. 3,
1989, each being incorporated herein by reference. Absorbent
articles having elasticized cuffs that are treated with a
composition that may be useful herein are disclosed in U.S. Pat.
No. 6,156,024, issued to Schulte et al. on Dec. 5, 2000, and U.S.
patent application Ser. No. 08/840,039 (now abandoned), both of
which are incorporated by reference.
[0126] The elasticized waist feature preferably comprises an
elasticized waistband (not shown) that may be constructed in a
number of different configurations including those described in
U.S. Pat. No. 4,515,595 issued to Kievit et al. on May 7, 1985;
U.S. Pat. No. 5,026,364 issued to Robertson on Jun. 25, 1991; and
the above referenced U.S. Pat. No. 5,151,092 issued to Buell et al.
on Sep. 29, 1992, each of these references being incorporated
herein by reference.
[0127] The elasticized side panels may be constructed in a number
of configurations. Examples of diapers with elasticized side panels
positioned in the ears (ear flaps) of the diaper are disclosed in
U.S. Pat. No. 4,857,067, issued to Wood, et al. on Aug. 15, 1989;
U.S. Pat. No. 4,381,781, issued to Sciaraffa, et al. on May 3,
1983; U.S. Pat. No. 4,938,753, issued to Van Gompel, et al. on Jul.
3, 1990; and U.S. Pat. No. 5,151,092, issued to Buell et al. on
Sep. 29, 1992; each of which are incorporated herein by
reference.
[0128] Exemplary fastening systems 570 are disclosed in U.S. Pat.
No. 4,846,815, issued to Scripps on Jul. 11, 1989; U.S. Pat. No.
4,894,060, issued to Nestegard on Jan. 16, 1990; U.S. Pat. No.
4,946,527, issued to Battrell on Aug. 7, 1990; U.S. Pat. No.
3,848,594, issued to Buell on Nov. 19, 1974; U.S. Pat. No. B1
4,662,875, issued to Hirotsu et al. on May 5, 1987; and U.S. Pat.
No. 5,151,092, issued to Buell et al. on Sep. 29, 1992; each of
which is incorporated herein by reference.
[0129] The diaper 50 is preferably applied to a wearer by
positioning one of the waist regions of the diaper, preferably the
second waist region 58, under the wearer's back and drawing the
remainder of the diaper between the wearer's legs so that the other
waist region, preferably the first waist region 56, is positioned
across the front of the wearer. The fastening system is then
applied to effect a side closure.
[0130] Of course, it will be recognized that any absorbent article
design may be utilized to carry out the methods of the present
invention, so long as skin care composition is applied to the
article so as to be transferred to the skin during use. The
disclosure above is merely for illustrative purposes.
[0131] The methods of the present invention may also employ
training pants to effect delivery of the desired skin care
composition. The term "training pants", as used herein, refers to
disposable garments having fixed sides and leg openings designed
for infant or adults wearers. Training pants (also referred in the
art as "pull on" products) are placed in position on the wearer by
inserting the wearer's legs into the leg openings and sliding the
training pant into position about the wearer's lower torso.
Suitable training pants are disclosed in U.S. Pat. No. 5,246,433,
issued to Hasse, et al. on Sep. 21, 1993, U.S. Pat. No. 5,569,234,
issued to Buell et al. on Oct. 29, 1996, U.S. Pat. No. 4,940,464,
issued to Van Gompel et al. on Jul. 10, 1990 and U.S. Pat. No.
5,092,861, issued to Nomura et al. on Mar. 3, 1992, the disclosure
of each of which is incorporated herein by reference.
[0132] Another disposable absorbent article for use in the present
methods are incontinence articles. The term "incontinence article"
refers to pads, undergarments (pads held in place by a suspension
system of same type, such as a belt, or the like), inserts for
absorbent articles, capacity boosters for absorbent articles,
briefs, bed pads, and the like regardless of whether they are worn
by adults or other incontinent persons. Suitable incontinence
articles are disclosed in U.S. Pat. No. 4,253,461 issued to
Strickland, et al. on Mar. 3, 1981; U.S. Pat. Nos. 4,597,760 and
4,597,761 issued to Buell; the above-mentioned U.S. Pat. No.
4,704,115; U.S. Pat. No. 4,909,802 issued to Ahr, et al.; U.S. Pat.
No. 4,964,860 issued to Gipson, et al. on Oct. 23, 1990; and in
U.S. patent application Ser. No. 07/637,090 filed by Noel, et al.
on Jan. 3, 1991 (PCT Publication No. WO 92/11830 published on Jul.
23, 1992). The disclosure of each of these references is
incorporated herein.
[0133] Another disposable absorbent article for use in the present
methods are feminine hygiene articles, such as sanitary napkins.
Suitable feminine hygiene articles are disclosed in U.S. Pat. No.
4,556,146, issued to Swanson et al. on Dec. 3, 1985, U.S. Pat. No.
B14,589,876, issued to Van Tilberg on Apr. 27, 1993, U.S. Pat. No.
4,687,478, issued to Van Tilburg on Aug. 18, 1997, U.S. Pat. No.
4,950,264, issued to Osborn, III on Aug. 21, 1990, U.S. Pat. No.
5,009,653, issued to Osborn, III on Apr. 23, 1991, U.S. Pat. No.
5,267,992, issued to Van Tilburg on Dec. 7, 1993, U.S. Pat. No.
5,389,094, issued to Lavash et al. on Feb. 14, 1995, U.S. Pat. No.
5,413,568, issued to Roach et al. on May 9, 1995, U.S. Pat. No.
5,460,623, issued to Emenaker et al. on Oct. 24, 1995, U.S. Pat.
No. 5,489,283, issued Van Tilburg on Feb. 6, 1996, U.S. Pat. No.
5,569,231, issued to Emenaker et al. on Oct. 29, 1996, and U.S.
Pat. No. 5,620,430, issued to Bamber on Apr. 15, 1997, the
disclosure of each of which is incorporated by reference
herein.
[0134] V. Treating Articles With Composition
[0135] In preparing absorbent articles to carry out the methods of
the present invention, the skin care composition is applied such
that during wear, at least some portion of the composition will
transfer from the treated article to the wearer's skin. That is,
skin care composition is either applied directly to one or more
wearer contacting surfaces, or is applied to alternate locations or
means such that the skin care composition is readily available for
transfer from one or more wearer contacting surfaces during use
without intervention by the user/caregiver. (For example, materials
positioned beneath the wearer contacting surface, encapsulated
compositions, etc.) Of course, to effectuate delivery of
composition to those body regions most susceptible to skin
disorders, it will be preferred to include the composition on the
portion of the topsheet and cuffs that will contact the wearer's
buttocks, genitals, intertriginous and anal regions during wear.
Additionally, the composition may be applied to other article
regions for delivery to one or more of the wearer's hips, abdomen,
back, waist, sides, thighs, etc. Any of a variety of application
methods that evenly distribute lubricious materials having a molten
or liquid consistency can be used. Suitable methods include
spraying, printing (e.g., flexographic printing), coating (e.g.,
contact slot coating, gravure coating), extrusion, or combinations
of these application techniques, e.g. spraying the skin care
composition on a rotating surface, such as a calender roll, that
then transfers the composition to the desired portion of the
article. The skin care composition can also be applied as a solid
material via any of a variety methods, for exanple extrusion.
[0136] When applied to the article's topsheet, the manner of
applying the composition to the article should be such that the
topsheet does not become saturated with the composition, at least
in the region corresponding to the liquid discharge region of the
article, if the composition is hydrophobic in nature. If the
topsheet becomes saturated with the composition in the liquid
discharge region, there is a greater potential for the composition
to block the topsheet openings, reducing the ability of the
topsheet to transmit liquid to the underlying absorbent core. Also,
saturation of the topsheet is not required to obtain the
therapeutic and/or protective benefits. Similarly, saturation of
other treated article components may not be necessary or desired to
transfer sufficient composition for desired skin benefits.
Particularly suitable application methods will apply the
composition primarily to the outer surface of the diaper
topsheet.
[0137] The minimum level of composition to be applied to the
articles wearer-contacting surface is an amount effective for
providing the therapeutic and/or protective benefits when the
composition is delivered pursuant to the present methods. The level
of composition applied will depend on various factors, including
the article component treated, the relative amount of surface area
of the wearer-contacting surface not treated with the composition,
the composition's content and the like. In general, with
compositions that are relatively hydrophobic and are to be applied
to essentially all of the top sheet, the composition is preferably
applied to the article topsheet in an amount ranging from about 0.1
mg/in.sup.2 (0.016 mg/cm.sup.2) to about 15 mg/in.sup.2 (2.33
mg/cm.sup.2), more preferably from about 1 mg/in.sup.2 (0.16
mg/cm.sup.2) to about 10 mg/in.sup.2 (1.55 mg/cm.sup.2). It will be
recognized that higher levels of skin care composition may be
applied to other article components where fluid handling properties
are not impacted (e.g., cuffs, waist band, side panels, etc.). It
will also be recognized that for compositions that are relatively
hydrophilic, higher add-on levels may be used on the topsheet
without adversely impacting liquid handling properties to an
unacceptable degree. Conversely, higher levels of a hydrophilic
composition may be undesired when applied to components (e.g.,
cuff, waist) other than the topsheet, to avoid wicking of exudates
to the edges of the article which may result in leakage.
[0138] Because the composition is preferably substantially
immobilized on the surface of the region treated, relatively small
amounts of composition are needed to impart the desired skin care
benefits. Applicants believe that the ability to use low levels to
impart the desired skin benefits is due to the fact that pursuant
to the methods described herein, composition is continuously,
automatically delivered as articles are worn. As indicated, the
ability to use relatively low levels of skin care composition,
allows the article's topsheet to maintain its liquid transfer
properties in the liquid discharge region.
[0139] The composition can be applied nonuniformly to the wearer
contacting surface of the article. By "nonuniform" it is meant that
the amount, location, pattern of distribution, etc. of the
composition can vary over the wearer-contacting surface, and may
further vary over specific regions of the article. For example, to
maintain the liquid handling performance of the topsheet, it may be
desired to apply the composition nonuniformly to the topsheet,
particularly if the composition is hydrophobic in nature. In this
regard, some portions of the treated surface of the article (and
regions thereof) can have greater or lesser amounts of composition,
including portions of the surface that do not have any composition
on it. When the composition is relatively hydrophobic, in one such
preferred embodiment the surface of the topsheet will have regions
where no composition is applied, particularly in areas of the
topsheet that correspond to the crotch region of the article. As
used herein, the crotch region of the article is the rectangle,
defined below, that is centered longitudinally and laterally about
the article's crotch point. The "crotch point" is determined by
placing the article on a wearer in a standing position and then
placing an extensible filament around the legs in a figure eight
configuration. The point in the article corresponding to the point
of intersection of the filament is deemed to be the crotch point of
the article. (It is understood that the crotch point is determined
by placing the absorbent article on a wearer in the intended manner
and determining where the crossed filament would contact the
article.) With regard to incontinence devices (e.g., diapers, adult
incontinent articles), the length of the crotch region corresponds
to 40% of the absorbent article's total length (i.e., in the
y-dimension). With regard sanitary napkins, the length of the
crotch region corresponds to 80% of the absorbent article's total
length. The width of the crotch region is equivalent to the width
of the widest absorbent core component as measured at the crotch
point. (As used herein, "absorbent core" components are those
materials involved with acquiring, transporting, distributing
and/or storing body liquids. As such, the term absorbent core does
not include the topsheet or backsheet of the absorbent article.) By
way of illustration, for an incontinent article having a length of
20 in. and a core width at the crotch point of 4 in., the crotch
region is the rectangle, centered on the crotch point, having a
length of 8 in. and a width of 4 in.
[0140] Surprisingly, while the topsheet or other components
comprising the composition are treated nonuniformly (e.g.,
microscopic or macroscopic regions where no composition is
applied), during wear of the article, the composition is
transferred to the wearer even in regions of the skin corresponding
to untreated regions within the topsheet or other components. The
amount and uniformity of composition transferred to the skin is
believed to depend on several factors, including, for example,
application pattern of the skin care composition, contact of the
wearer's skin to the treated article surface, friction created
during wear time between the wearer's skin and the treated region,
warmth generated from wearer to enhance the transfer of the
composition, the composition's properties, the materials which
constitute the composition, and the like.
[0141] Where the composition is applied nonuniformly, any pattern
may be utilized, including, for example, application of small
droplets (obtained via, e.g., spraying) discrete dots (obtained
via, e.g., gravure printing), stripes that run in the longitudinal
or lateral direction of the article (obtained via contact slot
coating), spirals that run in the longitudinal or lateral
direction, etc., patterned prints, etc. In those embodiments where
the topsheet comprises discrete, untreated regions, the percent
open area of the region of the topsheet that corresponds to the
crotch region of the article can vary widely. (As referred to
herein, the "percent open area" of the topsheet is determined by
(i) measuring the surface area of the topsheet that overlies the
crotch region, (ii) measuring the total surface area of the
untreated region(s) in this portion of the topsheet and (iii)
dividing the measurement in (ii) by the measurement in (i). As used
herein, "untreated" means a region of the topsheet having less than
about 0.01 mg/in.sup.2 (0.0016 mg/cm.sup.2) of the composition. In
this regard, the percent open area may be from about 1% to about
99%, from about 5% to about 95%, from about 10% to about 90%, from
about 15% to about 85%, from about 20% to about 80%, from about 25%
to about 75%, from about 30% to about 70%, or from about 35% to
about 65%. The percent open area required to achieve the desired
composition effect and the desired liquid handling properties of
the topsheet will be dictated largely by the characteristics of the
composition (in particular the composition's contents and its
relative hydrophobicit/hydrophilicy properties). One skilled in the
art will appreciate that the desired percent open area will be
readily determined through routine experimentation.
[0142] In general, with compositions that are relatively
hydrophobic and are to be applied such that regions of the topsheet
are not coated with the composition, the composition is preferably
applied to the article topsheet in an amount ranging from about
0.05 mg/in.sup.2 (0.0078 mg/cm.sup.2) to about 35 mg/in.sup.2 (5.43
mg/cm.sup.2), more preferably from about 1 mg/in.sup.2 (0.16
mg/cm.sup.2) to about 25 mg/in.sup.2 (3.88 mg/cm.sup.2), still more
preferably 4 mg/in.sup.2 (0.62 mg/cm.sup.2) to about 20 mg/in.sup.2
(3.1 mg/cm.sup.2). It will be recognized that for compositions that
are relatively hydrophilic, higher add-on levels may be used
without adversely impacting liquid handling properties of the
topsheet to an unacceptable degree. Of course, for articles having
relatively high percent open areas in the crotch, greater add-on
levels may be obtainable without adversely affecting liquid
handling by the topsheet.
[0143] In one preferred embodiment for carrying out the present
methods, the topsheet of the articles utilized will comprise
stripes of composition that run in the article's longitudinal
direction. These longitudinal stripes (or spirals) are separated by
longitudinal stripes where little or no composition is applied to
the topsheet. In these embodiments, each stripe of composition will
typically have a width of from about 0.1 in. to about 0.75 in.,
more typically from about 0.1 in. to about 0.5 in., and the width
of the stripes containing no composition will typically be from
about 0.1 in. to about 1 in., more typically from about 0.15 to
about 0.5 in. These ranges are applicable to typical infant diaper
designs. For larger products such as adult incontinent products,
these ranges may be higher.
[0144] Skin care composition can also be applied in nonuniform
patterns on other article components. In these cases, the open area
is calculated by the rectangle defined by the perimeters of the
skin care composition.
[0145] The composition can be applied to the article at any point
during assembly. For example, the composition can be applied to the
finished disposable absorbent product before it has been packaged.
The composition can also be applied to a given component (e.g.,
topsheet, cuffs, sides, waiste, etc.), at the converting site or by
the material supplier, before it is combined with the other raw
materials to form a finished disposable absorbent product. Again,
the composition can be applied to other zones of the article such
that the composition will migrate to one or more wearer contacting
surfaces during use.
[0146] The composition is typically applied from a melt thereof to
the article. Since in a preferred embodiment, the composition melts
at significantly above ambient temperatures, it is usually applied
as a heated composition to the article. Typically, the composition
is heated to a temperature in the range from about 35.degree. to
about 150.degree. C., preferably from 40.degree. to about
100.degree. C., prior to being applied to the article. Once the
melted composition has been applied to the article, it is allowed
to cool and solidify. Preferably, the application process is
designed to aid in the cooling/set up of the composition.
[0147] In applying compositions to the articles, contact slot
coating, spraying, gravure coating, extrusion coating methods are
preferred. One such method involves slot coating of the composition
on the article's topsheet after the topsheet is assembled with the
other raw materials into a finished product.
[0148] VI. Test Methods
[0149] A. Evaluating Erythema and Rash
[0150] 1. Test Summary
[0151] Two different infant diaper products are evaluated to
determine if there is a difference in the frequency and/or severity
of diaper rash and/or erythema in the diaper area in an average
infant population associated with the use of a test product (i.e.,
comprising a skin care composition on one or more wearer contacting
surface) over that associated with the control product (an
equivalent product, with the exception that it contains no skin
care composition).
[0152] 2. Investigational Plan
[0153] 2.1 Study Design
[0154] This study is conducted at a qualified clinical research
organization (CRO) and should comply with good clinical practices
(GCP) guidelines. The study is a randomized, double-blind, parallel
group comparison clinical trial in which both the trained skin
grader conducting skin evaluations and the caregivers of the
panelists will be unaware of the treatment assignment of the study
participants. A sufficient number of healthy infants will be
recruited from the general population residing in the geographical
area of the clinical site to participate and complete this study
such that two hundred (200) infants, one hundred (100) per group,
complete the study.
[0155] Two subject groups will participate in this study. Both
groups will include healthy infants, each comprising approximately
50% males and 50% females. The two groups will be age and/or diaper
size balanced (when wearing appropriately sized diapers). The two
groups will consist of healthy infants not taking medications for
conditions other than those that are routine for that age, such as
common cold/flu. All infants will present Fitzpatrick scale skin
type of I-III, and with no evidence of serious dermatological
conditions (i.e., not atopic). (Fitzpatrick I-III skin types
facilitate erythema grading.) Some level of erythema and diaper
rash in the diaper region is permissible (defined under exclusion
criteria below).
[0156] All infants who meet enrollment criteria will be assigned to
use the control product for one week (baseline). At the end of one
week, the infants will be randomly assigned into one of two
possible groups: one group will remain on the control product for
three weeks; the other group will use a test product for a period
of three weeks. As such, the total duration of the test for both
control and test product users is four weeks.
[0157] At the point when infants are randomized (Visit 2) into two
groups, no further use of ointments, creams, lotions, corn starch,
or powders will permitted on the skin in the diaper area during the
remaining period of the study. The use of soap, water, baby wipes,
or cleansing gels is permitted at diaper changes and baths.
[0158] The skin condition of infants will be evaluated at the
following times: enrollment into the study (Visit 1); following one
week baseline (Visit 2); twice per week for three weeks (Visits 3
through 8). Beginning with Visit 2, infants should be evaluated
three hours (+/-15 minutes) after being changed into a fresh
diaper. (Preferably, this change being the first after the
overnight diaper.) After Visit 2, subsequent visits should occur
three to four days apart.
[0159] 2.2 Procedure:
[0160]
[0161] Visit 1 (Enrollment)
[0162] A. Eligibility will be determined on the basis of the
eligibility requirements listed below.
[0163] B. Erythema and diaper rash evaluations will be conducted at
four sites in the diaper area (genitals, intertriginous, anal, and
buttocks) to confirm acceptance of the infant into the test.
Referring to FIGS. 2a, 2b, 2c, 2d, and 2e, the locations for grader
assessment of erythema and rash are shown. FIG. 2a shows the region
10 of the buttocks for assessment in both male and female subjects.
FIG. 2b shows region 100 of the genital area of a female subject
for assessment of erythema and rash.
[0164] FIG. 2b also shows navel 110 of a subject. For purposes of
assessing erythema and rash in the genital area of a female
subject, the upper portion of region 100, shown as line 100a, is
approximately 1 inch above the top of the labial aperture. FIG. 2c
shows region 200 of the genital area of a male subject for
assessment of erythema and rash.
[0165] FIG. 2c also shows navel 210 of a subject. For purposes of
assessing erythema and rash in the genital area of a male subject,
the upper portion of region 200, shown as line 200a, is
approximately 1 inch above the top of the base of the penis. FIG.
2d shows the anal region 300 for assessment of erythema and rash in
both male and female subjects. FIG. 2e shows regions 400 of the
intertriginous area of both male and female subjects for
assessment.
[0166] C. The parent/infant receives control product for the one
week baseline.
[0167] Visit 2
[0168] A. The infant is brought to the test site wearing a diaper
worn for three hour (+/-15 minutes).
[0169] B. The parent/infant proceeds to the skin grader for
evaluations of skin erythema and rash at four sites in the diaper
area (genitals, intertriginous, anal, and buttocks).
[0170] C. The infant is randomized into either the test or control
group and given product and instructions to eliminate other lotion,
creme, etc. use.
[0171] Visits 3 through 8
[0172] A. The infant is brought to the test site wearing a diaper
worn for three hour (+/-15 minutes).
[0173] B. The parentlinfant proceeds to the skin grader for
evaluations of skin erythema and rash at four sites in the diaper
area (genitals, intertriginous, anal, and buttocks).
[0174] C. Compliance with restriction on lotion, etc. is
confirmed.
[0175] 2.3 Study Population
[0176] As indicated, at least two hundred (200) infants are
expected to complete this study. Two subject groups will
participate in this study, each group comprising approximately 50%
males and 50% females. The two groups will be age and/or diaper
size balanced (when wearing appropriately sized diapers). The study
population will consist of healthy infants not taking medications
for conditions other than those that are routine for that age such
as common coldl/flu, with a Fitzpatrick scale skin type of I-III,
and no evidence of serious dermatological conditions (e.g., not
atopic). The presence of erythema and diaper rash is
permissible.
[0177] 2.3.1. Inclusion Criteria
[0178] Each Infant must:
[0179] a) have no serious dermatological conditions in the diaper
area,
[0180] b) be fill time disposable diaper user,
[0181] c) have a caregiver willing to not use lotions, creams,
powders, or other skin preparations in the diaper area during the
study.
[0182] The eligibility of each potential infant is also determined
by the completion of a medical and dermatological history
questionnaire. Subjects will be excluded from this study for one or
more of the reasons listed below under exclusion criteria.
[0183] 2.3.2 Exclusion Criteria
[0184] Babies are excluded from participation in the study if:
[0185] they do not meet the inclusion criteria.
[0186] at the first visit they have a diaper rash grade
>2.5.
[0187] they have diabetes or chicken pox.
[0188] they have psoriasis, ichthyosis. at Visit 1, they have a
significant eruption in the diaper area and it is the opinion of
the Clinical Research Organization's Principal Investigator or skin
grader that the baby should be excluded.
[0189] use medication of any kind (e.g., oral antibiotics,
antifungal agents, corticosteroids taken orally or topically
applied to the skin), which in the opinion of the Clinical Research
Organization's Principal Investigator and/or skin grader may have
an influence on baby's skin in the diaper area.
[0190] they do not fit the diaper as determined at Visit 1.
[0191] hey have any other medical condition that could compromise
the study.
[0192] they have experienced diarrhea within the past four
days.
[0193] 2.4 Test Materials
[0194] The two treatment groups that will be included in this study
are as follows:
[0195] Test Group: will use diapers having a skin care composition
that is transferred to the wearer during use.
[0196] Control Group: will use equivalent diapers to the Test
Group, but the diapers have no skin care composition that is
transferred to the wearer during use.
[0197] 2.5 Randomization and Regimen
[0198] Infants will be randomly assigned, using a statistically
valid randomization schedule, at Visit 2 to either the test or
control product group. The groups should be balanced for age or
diaper size, sex, and diaper rash severity (e.g., mild, moderate,
severe rash). Twins (or multiple births) will be assigned to use
the same product.
[0199] 2.6 Regimen & Compliance with Treatment
[0200] Each infant should arrive at the investigative site at
approximately the same time of the day for each visit. The infants
are expected to wear their assigned products only. No ointments,
creams, lotions, or powders should be used on the skin in the
diaper area after visit 2. The use of soap, water, baby wipes, or
cleansing gels is permitted at diaper changes.
[0201] Subjects should come to the site such that when their skin
is evaluated they will have been wearing a product for three hours
(+/-15 minutes). Preferably, this product is the one immediately
following the overnight diaper. In the event of a bowel movement
within the 3 hour time frame, the diaper should be changed as
needed, and skin evaluation should proceed as scheduled.
[0202] 2.7 Blinding
[0203] The test is a randomized, double-blind, parallel group
comparison clinical trial in which a trained skin grader conducting
skin evaluations, as well as the caregiver of the panelists, will
be unaware of the treatment assignment of the study
participants.
[0204] 2.8 Subject Discontinuation/Termination
[0205] In addition to the exclusion criteria, a baby will be
dropped from the study due to:
[0206] failure to appear for more than one visit,
[0207] medication that is required which will have a significant
effect on the baby's skin condition in the diaper area,
[0208] they develop erythema or diaper rash >2.5 during the
course of the study,
[0209] non-compliance--if they use their own diapers during the
study, or if they use lotion, powders, etc.
[0210] any illness which the Clinical Research Organization's
Principle Investigator decides may effect the results of the
study.
[0211] 2.9 Observations and/or Measurements
[0212] Skin evaluations will be conducted by a trained skin grader
who will be blinded as to the assignment of treatments for each
subject. The same grader should be used for all examinations. The
grader should be experienced in evaluating infant skin conditions
in the diapered region, especially diaper rash. Preferably, the
grader will be a nurse. The grader will be separated from the area
where the diapers are removed so that the grader will not see what
diapers the babies are wearing.
[0213] At each examination period, each baby will be examined for
erythema first, then diaper rash, at 4 locations on the body
(genitals, intertriginous, anal, and buttocks).
[0214] Erythema and diaper rash severity will each be evaluated
using the grading scales shown below. A pictorial description of
the 4 diaper locations are shown in FIGS. 2a through 2e.
[0215] 3. Statistical Methods
[0216] 3.1 Planned Statistical Analyses
[0217] For purposes of the present disclosure, evidence of a test
product improvement in rash or erythema is defined as a statistical
or non-statistical (as defined above) difference at: (a) one or
more of the 4 skin grading locations for the study group as a
whole; or (b) one or more of the 4 skin grading locations for any
gender or age or diaper size subset of the study group.
[0218] Baseline Visit will be defined as Visit 2; post-baseline
visits will be defined as Visits 3 through 8. For all parameters,
separate analyses will be done for each site. The same analyses
will be done on the erythema (i.e., redness) severity grades as for
the diaper rash severity grades. The primary comparison of interest
is between the treatment groups.
[0219] The frequency of diaper rash (or erythema) will be analyzed
in two ways. First, the presence of diaper rash (erythema) at any
time during the course of the study will be evaluated. For each
treatment group, the number and percentage of infants for which
diaper rash (or erythema) was present (i.e., diaper rash severity
grade is greater than 0 at any post-baseline visit) and absent
(i.e., diaper rash severity grade equals 0 for every post-baseline
visit) will be calculated. These dichotomous treatment group
responses (i.e., presence and absence) will be analyzed using a
chi-square test. The effects of sex or age or diaper size should be
investigated using Mantel-Haenszel statistics or, if appropriate, a
weighted least squares or loglinear categorical model.
[0220] The second way in which diaper rash (or erythema) frequency
will be analyzed is to evaluate the number of post-baseline visits
at which diaper rash (or erythema) was present for each subject
(i.e., diaper rash grade greater than zero). The number of
post-baseline visits with diaper rash (or erythema) will be
analyzed using a loglinear Poisson regression model. The effects of
sex or age or diaper size should be investigated by incorporating
these effects into the model.
[0221] Diaper rash (or erythema) severity will be analyzed by
evaluating average diaper rash (or erythema) severity over all
post-baseline visits. For each subject, the average of all
post-baseline visit diaper rash (or erythema) severity grades will
be computed. These average severity grades will be analyzed using a
one-way analysis of variance model. A transformation (e.g., log)
may be done prior to analysis to improve the distributional
characteristics of the averages (i.e., improve the homogeneity of
the treatment group variances, improve the normality of the
analysis of variance residuals). Alternatively, a nonparametric
analog to the one-way analysis of variance may be done (e.g.,
Wilcoxon's Rank Sum Test) if the analysis of variance residuals do
not adequately fit a normal distribution and/or the treatment group
variances are not homogenous enough. The effects of sex or age or
diaper size should be investigated by incorporating these effects
into the analysis of variance model.
2 ERYTHEMA GRADING SCALE 0 None Skin is clear (may have some very
slight dryness) 0.5 Slight Faint to definite pink in a very small
area (<2%) 1.0 Mild Faint to definite pink in small area (2-10%)
or Definite redness in very small area (<2%) 1.5 Mild/Mod Faint
to definite pink in larger area (>10%) or Definite redness in a
small area (2-10%) or Very intense redness in very small area
(<2%) 2.0 Moderate Definite redness in larger area (10-50%) or
Very intense redness in very small area (<2%) w/edema 2.5
Mod/Severe Definite redness in very large area (>50%) or Very
intense redness in small area (2-10%) w/edema 3.0 Severe/Very
intense redness in larger area (>10%) w/edema
[0222]
3 RASH GRADING SCALE 0 None Skin is clear (may have some very
slight dryness and/or a single papule but no erythema) 0.5 Slight
Erythema: Faint to definite pink in a very small area (<2 %) May
also have a single Papule; and May also have: Skin Integrity: Some
very slight dryness 1.0 Mild Erythema: Faint to definite pink in
small area (2-10%) or Definite redness in very small area (<2%)
and/or Papules: A few scattered papules (2-5) May also have: Skin
Integrity: Some slight dryness or scaling 1.5 Mild/Mod Erythema:
Faint to definite pink in larger area (>10%) or Definite redness
in a small area (2-10%) or Very intense redness in a very small
area (<2%) and/or Papules: Slightly scattered papules covering a
single or multiple areas (<10%) May also have: Skin Integrity:
Moderate dryness or scaling 2.0 Moderate Erythema: Definite redness
in large area (10-50%) or Very intense redness in very small area
(2%) and/or Papules/Pustules: Single to several areas (10-50%) of
papules, with 0-5 pustules May also have: Skin Integrity: Some
slight desquamation or edema 2.5 Mod/Severe Erythema: Definite
redness in very large area (>50%) or Very intense redness in
small area (2-10%) and/or Papules/Pustules: Larger areas (>50%)
of multiple papules or numerous pustules or both and/or May also
have: Skin Integrity: Moderate desquamation and edema 3.0 Severe
Erythema: Very intense redness in larger area (>10%) and/or Skin
Integrity: severe desquamation, severe edema, erosion and
ulceration May also have: Large areas of numerous confluent papules
or Numerous pustuics/vesicles
[0223] This method uses a removable skin analog material that is
placed on a wearer's skin for a controlled period of time. After
the skin analog has been removed, it is extracted using an
appropriate solvent and the amount of skin care composition
deposited thereon is determined using known analytical methods. The
method is described for use with infant diapers comprising skin
care compositions, as defined herein. One of skill in the art will
recognize the appropriate changes for other skin care compositions,
absorbent articles, or wearer types.
[0224] Subjects
[0225] Approximately equal numbers of male and female infants
should be selected using the following inclusion and exclusion
criteria. Sufficient infants should be selected to ensure that
there are at least fifteen subjects per condition and transfer time
who complete all aspects of the test.
[0226] Inclusion Criteria
[0227] a. Healthy infant
[0228] b. Caregiver willing to not use lotions, creams, powders or
other skin preparations in the diaper area for the duration of the
test.
[0229] c. Infants who wear disposable diapers fill time
[0230] d. Caregiver willing to give child bath the evening before
the study and not again until after completion of the study
[0231] e. Caregiver will to have child refrain from swimming from
the evening before the study until after completion of the
study.
[0232] f. Preferably, infants who have infrequent bowel
movements
[0233] Exclusion Criteria
[0234] a. The infant has been ill within the last four days
[0235] b. Diarrhea (soft stool) any time during the four days
before the test
[0236] c. Medication which might increase frequency of bowel
movements (e.g., oral antibiotics, anti fungal agents,
corticosteroids)
[0237] d. Damaged skin in or around the test site (e.g., from
sunburn, active dermal lesions, or the like)
[0238] e. Known allergies or irritation from adhesive or skin care
ingredients
4 Materials In Vivo Transfer Skin Analog: Dermatological
Tape-TEGADERM Tape No. 1622W available from 3M Health Cares, St.
Paul, MN Sample Container Glass jar with closure available from VWR
Scientific, West Chester, PA as catalog Number 15900-242 Tape
Release Powder Baby powder (comprising only talc and fragrance)
available from Johnson & Johnson, New Brunswick, NJ Surgical
Gloves Available from Best Manufacturing Co., Menlo GA, as product
6005PFM. Extraction and Analysis Extraction Solvent
Dichloromethane, available from Sigma-Aldrich of St. Louis, MO as
27056-3 Stearyl alcohol Aldrich 25876-8 1-Hexadecanol Aldrich
25874-1 Dispensing Flask 10 ml Gas Chromatograph Flame ionization
Detector, Hewlett Packard Model 5890 is suitable. Column Capillary
column: Chrompack CP Sil-5 CB, 2 meters X 0.25 mm id, 0.12 micron
film thickness fused silica capillary (no substitutions)
Instrumental Data Must be able to reproducibly determine areas of
peaks of System interest.
[0239] Method
[0240] In Vivo Transfer
[0241] A. Confirm from the subject's caregiver that the subject has
been bathed within the last 24 hours and that no lotions, powders,
etc. have been applied to the diapered region of the subject's skin
since bathing.
[0242] B. Wearing the surgical gloves, place the subject on the
table and remove his/her diaper.
[0243] C. Turn the subject on his/her stomach.
[0244] D. Remove the release liner from a TEGADERM tape and lightly
brush J&J Baby Powder over the adhesive surface (Wear surgical
gloves, or the like, during application to prevent contamination of
the tape). Provide sufficient powder such that there is a light
coat of powder over all of the tape except the edges. (This step is
done to keep the tape from adhering too aggressively to the child's
skin.).
[0245] E. FIGS. 3a and 3b illustrate placement location for the
TEGADERM tape, shown in those figures as tape 700. Apply the tape
700 to the child's right buttock. The tape 700 is to be applied to
the highest point on the child's buttock immediately adjacent to,
but not in, the child's gluteal groove. A second tape 700 may be
applied to measure transfer at two time increments or the effect of
an additional diaper. If a second tape is used, apply the tape 700
on the left buttock using the procedure described above.
[0246] F. Change diapers according to the following protocol: 3
hour transfer time--1 diaper; 6 hour transfer time--2 diapers
(change at 3 hours); 24 hour transfer times ad lib by caregiver.
For 24 hour transfer times the following additional instructions
are to be followed:
[0247] 1. Use only water and a washcloth for cleaning the diapered
area for the duration of the test. Do not use baby wipes. Avoid
touching the area around the tapes with hands or any cleaning
implement.
[0248] 2. Do not use skin care products (lotions, ointments,
creams, soap, etc.) for the duration of the test.
[0249] 3. Do not bathe the subject for the duration of the
test.
[0250] 4. Use only the test diapers. Record the time of each diaper
change.
[0251] 5. Record the time of any bowel movement and clean the
subject with water and a wash cloth.
[0252] G. Record the time each diaper was applied for all test
diapers.
[0253] H. Recall the subject near the end of the predetermined
transfer time.
[0254] I. Remove the test diaper. If the child has had a bowel
movement, the study personnel should remove the tape 700 and
discard it (the subject has then completed the test and data from
that subject are not included in the analysis). If the subject has
urinated, the tape 700 will be acceptable for analysis as described
below.
[0255] J Test facility personnel should wear surgical gloves and
remove the tape 700 by grasping the edge of the tape 700 with
tweezers and gently peeling the remaining portion of the tape 700
from the skin.
[0256] K. Place the used tape 700 in one of the glass jars and
close the lid. Make sure the jar is properly labeled for subsequent
sample identification.
[0257] L. At the completion of the test collect all of the samples
in the jars for analysis as described below.
[0258] Extraction and Analysis
[0259] This method is designed for use with the preferred skin care
composition, the skin care composition of Table 1. One of ordinary
skill in the art will recognize what adaptions may be necessary to
extract and analyze the level of other skin care compositions. In
principle: 1) one of the major ingredients of the composition is
extracted from the skin analog using an appropriate solvent; 2) gas
chrornatographic or other appropriate quantitative analytical
techniques are then used to determine the level of the major
ingredient in the extract; 3) amount of skin care composition is
calculated per unit area based on amount of major ingredient in
extract and the area of the tape.
[0260] Internal Standard/Extraction Solvent
[0261] Prepare an internal standard/extraction solvent by
accurately weighing 100.+-.2 mg of 1 -hexadecanol into a small
beaker. Dissolve the 1-hexadecanol in dichloromethane and transfer
to a 1 liter volumetric flask. Rinse the beaker 3 more times with
dichloromethane transferring each rinse portion to the volumetric
flask. Fill the volumetric flask to volume and mix well. This
solution will be used to deliver the internal standard and extract
skin care composition from the tapes. When not being used, this
container should be kept tightly capped to prevent evaporation of
solvent.
[0262] Calibration Standard
[0263] Prepare a calibration standard of known concentration by
accurately weighing (.+-.0.1 mg) 10.+-.1 mg of the stearyl alcohol
into a 100 ml volumetric flask. Record the weight of stearyl
alcohol used. Add the internal standard/extraction solvent to the
flask and mix to dissolve. Fill to volume and mix well. When not
being used, this container should be kept tightly capped to prevent
evaporation of solvent. This solution will be used to determine the
relative response of the stearyl alcohol to the 1-hexadecanol
internal standard for calibration of the instrument.
[0264] Preparation and Calibration of the Gas Chromatograph
[0265] All equipment should be installed, operated and maintained
according to manufacturer's recommendations. Install the column and
check all the gas flows with the column oven at 100.degree. C. and
the injection port and detector at operating temperatures. The GC
will be operated under the following conditions:
5 Carrier Gas: Hydrogen (Helium may be used); flow rate 1.5 ml/min
Injection Port: 325.degree. C.; Split vent flow 30 ml/min; Septum
purge 2 mL/min; straight through liner with glass wool plug; Merlin
microseal. Injection volume: 2 .mu.l split FID Detector:
350.degree. C.; set gas flows according to manufacturer
suggestions. Typical gas flows are 400 ml/minute for air, 30
ml/minute for hydrogen and 30 ml/minute for the auxiliary (make up)
gas. Column Oven: 100.degree. C. ramped at 15.degree. C./minute to
325.degree. C.; hold for 10 minutes
[0266] Insure that all connections are tight and leak free. Ignite
the detector and allow it to stabilize. Condition the column at
325.degree. C. for 30 minutes. Clean the syringe with
dichloromethane as needed. The syringe should also be rinsed with
dichloromethane several times after each injection. Make several
blank runs with injections of dichloromethane to ensure that a good
baseline is obtained and that no extraneous peaks are present in
the chromatogram. If extraneous peaks are present or baseline is
not suitable, trouble shoot and correct problem(s).
[0267] Calibrate the instrument using the calibration standard
prepared previously. Consult the data system manufacturer's
instructions for the proper sequence of operations. Calculations
should be performed in a manner similar to that described in
CALCULATIONS below in order to provide the desired result.
[0268] Sample Analysis Procedure
[0269] 1) Remove the lid from the sample jar and add 10 ml of the
extraction solvent/internal standard solution using the dispensing
flask. Replace the cap and swirl the contents to insure that the
tape 700 is not adhering to the sides of the jar and is totally
submersed in solvent. Repeat for all samples.
[0270] 2) Allow the samples to sit 16 hours (typically done
overnight).
[0271] 3) Swirl the contents of the jar to mix. Using a transfer
pipette, transfer an aliquot of the sample extract to a properly
labeled autosampler vial. Cap the vial. Replace jar lid and retain
until analyses are complete. Repeat for all samples.
[0272] 4) Place the vials in the autosampler in random order and
start the analyses using the GC conditions described above. The
first vial should be a dichloromethane blank. Several "check"
standards should be placed (about every 20th sample) through out
the run to verify correct operation.
[0273] 5) At the completion of the run, check each chromatogram to
insure proper analysis. If a problem is suspected, trouble shoot
and correct. Reanalyze samples as needed.
[0274] Calculations
[0275] The total micrograms of stearyl alcohol in each sample
extract is calculated based on the relative response of the stearyl
alcohol peak to that of the 1-hexadecanol internal standard. The
ratio of the peak areas is multiplied by the relative response
factor (determined at time of instrument calibration) and the
micrograms of internal standard in the extract to yield the total
.mu.g of stearyl alcohol in a sample.
[0276] Instrument Calibration
[0277] Determine the instrumental relative response factor for the
stearyl alcohol and the internal standard based on the areas of the
stearyl alcohol and 1-hexadecanol peaks in the calibration standard
chromatogram. 1 Response factor ( R f ) = Area inst weight inst
.times. weight sa Area sa .times. 10
[0278] where
[0279] Area.sub.inst GC peak area for the internal standard
[0280] Area.sub.sa GC peak area for the stearyl alcohol
[0281] weight.sub.inst micrograms of the internal standard used to
prepare internal standard/extraction solvent
[0282] weight.sub.sa micrograms of the stearyl alcohol used to
prepare the calibration standard
[0283] Sample Calculations
[0284] Calculate the total micrograms of stearyl alcohol in each
sample using the peak areas from the sample chromatogram in the
following equation: 2 Total g SA = Area sa Area inst .times. R f
.times. weight inst 100
[0285] where
[0286] Area.sub.inst GC peak area for the internal standard
[0287] Area.sub.sa GC peak area for the stearyl alcohol
[0288] weight.sub.inst micrograms of the internal standard used to
prepare internal standard/extraction solvent
[0289] Report amount of skin care composition transferred in
mg/cm.sup.2 where: 3 Composition Transferred = 0.001 .times. g of
stearyl alcohol (concentration of stearyl alcohol in composition)
.times. (tape area)
[0290] For the method described above the concentration of stearyl
alcohol in the composition is 41% and the tape patch measures 4.4
cm.times.4.4 cm. 4 Composition Transferred = ( 0.001 .times. g of
stearyl alcohol ) / ( 0.41 .times. 4.4 cm .times. 4.4 cm ) 0.000126
.times. g of stearyl alcohol ( mg / cm 2 )
[0291] B. Water Vapor Transmission Rate Measurement
[0292] The Water Vapor Transmission Rate (WVTR) for the sample
materials was calculated in accordance with ASTM Standard E96-80.
Circular samples measuring three inches in diameter were cut from
each of the test materials and a control which was a piece of
CELGUARD.RTM. 2500 film from Hoechst Celanese Corporation of
Sommerville, N.J. CELGUARD.RTM. 2500 film is a microporous
polypropylene film. Five samples were prepared for each material.
The test dish was a number 60-1 Vapomoter pan distributed by
Thwing-Albert Instrument Company of Philadelphia, Pa. One hundred
millimeters of water were poured into each Vapometer pan and
individual samples of the test materials and control material were
placed across the open tops of the individual pans. Screw-on
flanges were tightened to form a seal along the edges of the pan,
leaving the associated test material or control material exposed to
the ambient atmosphere over a 6.5 centimeter diameter circle having
an exposed area of approximately 33.17 square centimeters. The pans
were placed in a forced air over at 100.degree. F. (32.degree. C.)
for 1 hour to equilibrate. The oven was a constant temperature oven
with external air circulating through it to prevent water vapor
accumulation inside. A suitable forced air oven is, for example, a
Blue M Power-O-Matic 60 oven distributed by Blue M Electric Company
of Blue Island, Ill. Upon completion of the equilibration, the pans
were removed from the oven, weighed and immediately returned to the
oven. After 24 hours, the pans were removed from the oven and
weighed again. The preliminary test water vapor transmission rate
values were calculated as follows:
Test WVTR=(grams weight loss over 24 hours).times.315.5
g/m.sup.2/24 hrs
[0293] The relative humidity within the oven was not specifically
controlled.
[0294] Under predetermined set conditions of 100.degree. F.
(32.degree. C.) an ambient relative humidity, the WVTR for the
CELGUARD.RTM. 2500 control has been determined to be 5000 grams per
square meter for 24 hours. Accordingly, the control sample was run
with each test and the preliminary test values are corrected to set
conditions using the following equation:
WVTR=(Test WVTR/control WVTR).times.5000 g/m.sup.2/24 hrs.
(g/m.sup.2/24 hrs)
[0295] VII. Specific Examples
[0296] The following are specific illustrations of (a) treating
diaper topsheets with skin care compositions and (b) methods of the
present invention which utilize articles comprising those
topsheets. Similar approaches may be utilized to treat other
components for providing treated articles for use in the present
methods.
EXAMPLE 1
Preparation of an Absorbent Article Having a Topsheet Comprising a
Skin Care Composition
[0297] A. Preparation of Skin Care Composition
[0298] A skin care composition (Composition A) is made by mixing
the following melted (i.e., liquid) components together: Petrolatum
(available from Witco Corp., Greenwich, Conn.), Stearyl Alcohol
(available from The Procter & Gamble Company, Cincinnati, Ohio
as CO1897) and aloe extract (available from Madis Botanicals, Inc.,
South Hackensack, N.J. as Veragel Lipoid in Kaydol). The weight
percentages of these components are shown in Table I below:
6 TABLE I Component Weight % Petrolatum 58 Stearyl Alcohol 41 Aloe
1
[0299] B. Preparation of a Treated Article by Contact Slot
Coating
[0300] Composition A is placed into a heated tank operating at a
temperature of 170.degree. F. The composition is subsequently
applied with a contact applicator (using, for example, a Meltex
EP45 hot melt adhesive applicator head having 5 slots and operating
at a temperature of 10.degree. F.) onto the topsheet of an article
in a striped pattern where the stripes run in the article's
longitudinal direction. Specifically, 5 stripes are applied, each
stripe measuring 0.25 in. wide (i.e., in the articles lateral
direction) and 11.75 in. long at an add-on level =7.7 mg/in.sup.2
(12 g/m.sup.2, 1.19 mg/cm.sup.2). The distance between the stripes
is 0.31 in.
[0301] The article to which skin care composition is added in this
example is commercially available Pampers Premium (Size 4) diapers,
available from Procter & Gamble, Cincinnati, Ohio.
EXAMPLE 2
Method of Improving Skin Health
[0302] An infant weighing 20 lbs who typically exhibits moderate
diaper rash and erythema is diapered for a period of 21 days using
the diaper of Example 1. The infant's diaper is changed according
to the routine patterns of the caregiver. (Typical diapering
patterns consist of changes every three to four hours during the
day and application of a fresh diaper before overnight sleep.) No
intervention by the caregiver, in the form of manual application of
skin protective or moisture repellent products, occurs during this
period. During the 21 day period, the subject is observed to have
reduced severity of rash and erythema.
EXAMPLE 3
Method of Improving Skin Health
[0303] An active incontinent adult weighing 165 lbs. who constantly
uses absorbent articles and who persistently has mild erythema uses
an adult incontinent product analogous to the diaper of Example 1
for a period of at least about 5 days. The subject's article is
changed according to the routine patterns of the user. (Typical
changing patterns consist of changes every four to five hours
during the day and application of a fresh article before overnight
sleep.) No intervention by the user, in the form of manual
application of skin protective or moisture repellent products,
occurs during this period. At the end of the 5 day period, the
subject is observed to have reduced or resolved erythema.
EXAMPLE 4
Method of Improving Skin Health
[0304] An infant weighing 32 lbs. exhibiting mild diaper rash and
erythema is diapered for a period of at least about 5 days using
the diaper of Example 1 during overnight sleep only. (That is, a
untreated article is used throughout the day.) The infant's diaper
is changed according to the routine patterns of the caregiver. No
intervention by the caregiver, in the form of manual application of
skin protective or moisture repellent products, occurs during this
period. At the end of the 5 day period, the subject is observed to
have reduced or resolved rash and erythema.
EXAMPLE 5
Method of Maintaining Skin Health
[0305] An infant weighing 25 lbs. exhibiting no diaper rash or
erythema is diagnosed with otitis media and is prescribed a course
of systemic antibiotics. Based on experience with conventional
(untreated) diapers, the caregiver expects that the infant will
develop erythema and/or diaper rash resulting from loose stools. As
a result, diapers such as that described in Example 1 are used
continuously throughout the period of administration of the
antiobotic. No intervention by the caregiver, in the form of manual
application of skin protective or moisture repellent products,
occurs during this period. Throughout the period of antibiotic
administration, the subject exhibits no erythema or diaper
rash.
EXAMPLE 6
Breathable Films
[0306] Three breathable films with varying polymer blends were
prepared and then each of the films were prepared. Each of the film
formulations contained, on a total weight percent basis, 65%
English China Supercoat calcium carbonate (CaCO.sub.3) with a 1
micron average particle size and a 7 micron top cut. The calcium
carbonate was obtained form ECCA Calcium Products, Inc. in
Sylacauga, Ala., a division of ECC International. The calcium
carbonate was blended with 15-25% by weight of linear low density
polyethylene made from a blend of DOWLEX.RTM. 2517 linear low
density polyethylene and DOWLEX.RTM. 2532 linear low density
polyethylene blended in a weight ratio of 1:4 such that the melt
indenx of the blend was 10 M.I. (/10 minutes at 190.degree. F.).
The DOWLEX.RTM. polymers are available from Dow Chemical U.S.A.,
Midland, Mich. The remaining 10-20% by weight of the formulation
comprised Himont KS051P polypropylene-based polymer from Himont,
USA of Wilmington, Del. The KS051P polymer is an olefinic
thermoplastic elastomer or TPO multistep reactor product wherein an
amorphous ethylene propylene random copolymer is molecularly
dispersed in a predominately semicrystalline high polypropylene
monmer/low ethylene monomer continuous matrix. The amorphous
component acts as the tacktifying or bonding agent as it begins to
soften at about 55.degree. C. As shown in Table I below, sample 1
contained 65% calcium carbonate, 10% KS051P polymer and 25% linear
low density polyethylene. Sample 2 contained 65% calcium carbonate,
15% KS051P polymer and 20% linear low density polyethylene. The
third sample contained 65% calcium carbonate, 20% KS051P polymer
and 15% linear low density polyethylene. Each of the three
formulations were blown into films at a melt temperature of
375.degree. F. (191.degree. C.) at a blow up ratio of approximately
1.7 to produce films having an unstretched gauge of approximately
1.25 mils (50 gsm). Each of the films was subsequently stretched on
a machine direction orientation (MDO) unit at a stretch ratio of
3.times. and at a temperature of 140.degree. F. (60.degree. C.).
The resultant films were breathable as indicated by the water vapor
transmission rate data set forth in Table II below and has basis
weights of approximately 14 grams per square meter.
7TABLE II SAM- CaCO3 LLDPE KS051P WVTR PLE (% by weight) (% by
weight) (% by weight) (g/m.sup.2/24 hr) 1 65 25 10 4530 2 65 20 15
4300 3 65 15 20 3710
EXAMPLE 7
Breathable Films
[0307] In this Example, 65% by weight calcium carbonate and 30% by
weight linear low density polyethylene were blended. As shown by
Table III, to the basic blend there was added a series of
recognized tacktifying or bonding agents in a weight percent of 5%.
The bonding agents included REGALREZ.RTM. 1094, 3102 and 1126
bonding agents as well as ZONATAC.RTM. 501L and EASTMAN.RTM. 1023PL
bonding agents. In addition, the film formulation from sample 2 of
Example 6 was also formed into a film in the same fashion as
described with respect to Example 6. Each of the films was blown at
a blow-up ratio of 1.7 to a guage of approximately 1.5 mils (60
gsm). The films were stretched at 146.degree. F. (63.degree. C.) in
the machine direction to three times (3.times.) their original
length. This stretching temperature which was below the melting
point (235.degree. F./113.degree. C.) of the predominately linear
polyolefin polymers. The water vapor transmission rate for each of
the films was measured. The results are presented in Table III
below.
8TABLE III CaCO3 LLDPE WVTR Bonding Agent Wt % Wt % Wt %
(g/m.sup.2/24 hr) KS050 1 65 20 4300 REGALREZ .RTM. 1094 5 65 30
2300 REGALREZ .RTM. 3102 5 65 30 3840 REGALREZ .RTM. 1126 5 65 30
3198 ZONATAC .RTM. 501L 5 65 30 2990 EASTMAN .RTM. 1023PL 5 65 30
4900
* * * * *