U.S. patent application number 09/759123 was filed with the patent office on 2001-08-30 for antiperspirant compositions.
Invention is credited to Chuah, Beng Sim, Clare, Sarah Jane, Franklin, Kevin Ronald, Hough, Gordon Charles, Turner, Graham Andrew.
Application Number | 20010018045 09/759123 |
Document ID | / |
Family ID | 26243406 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010018045 |
Kind Code |
A1 |
Chuah, Beng Sim ; et
al. |
August 30, 2001 |
Antiperspirant compositions
Abstract
Soft solid antiperspirant formulations in which a particulate
antiperspirant active material is suspended in a continuous phase
containing a water-immiscible liquid which is structured by
specified proportions of an organic polymeric thickener and a
second structurant selected from fibre-forming structurants and
waxes (often other than fatty alcohols) or a mixture of both. Such
soft solid formulations avoid or minimise problems inherent in
production of many published formulations such as sensitivity to
small changes in concentration of the structurant.
Inventors: |
Chuah, Beng Sim;
(Merseyside, GB) ; Clare, Sarah Jane; (Merseyside,
GB) ; Franklin, Kevin Ronald; (Merseyside, GB)
; Hough, Gordon Charles; (Merseyside, GB) ;
Turner, Graham Andrew; (Merseyside, GB) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Family ID: |
26243406 |
Appl. No.: |
09/759123 |
Filed: |
January 12, 2001 |
Current U.S.
Class: |
424/65 |
Current CPC
Class: |
A61K 8/28 20130101; A61K
8/042 20130101; A61K 8/37 20130101; A61K 8/585 20130101; A61Q 15/00
20130101; A61K 8/92 20130101; A61K 8/732 20130101; A61K 8/8182
20130101; A61K 8/73 20130101; A61K 8/26 20130101; A61K 8/342
20130101 |
Class at
Publication: |
424/65 |
International
Class: |
A61K 007/32 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2000 |
GB |
0000875.5 |
Jul 10, 2000 |
GB |
0016942.5 |
Claims
1. An antiperspirant soft solid composition having a continuous
phase which contains water-immiscible liquid, and contains i) 1.5
to 15%, by weight of the composition, of an organic polymer which
is effective to increase the viscosity of the water-immiscible
liquid; ii) second structuring material selected from the group
consisting of a) 0.5 to 7% by weight of the composition of
structurant which forms a network of fibres within the continuous
phase, b) 0.5 to 15% by weight of the composition of waxes, other
than fatty alcohols, which are solid at temperatures of 30 C. and
below, but melt below 95 C., and c) mixtures thereof; iii) from 0
to 3%, by weight of the composition, of fatty alcohol which is
solid at 20 C., with the proviso that the total amount of any said
fatty alcohol is less than the total of said organic polymer (i)
and second structuring material (ii); and a particulate
antiperspirant active in suspension in said continuous phase.
2. A composition according to claim 1 wherein the total amount of
any said fatty alcohol which is solid at 20 C. is from 0 to 1.5% by
weight of the composition.
3. A composition according to claim 1 or claim 2 wherein the total
amount of said organic polymer (i) and second structuring material
(ii) is from 3% to 15% by weight of the composition.
4. A composition according to claim 1 or claim 2 wherein the total
amount of said organic polymer (i) and second structuring material
(ii) is from 4% to 12% by weight of the composition.
5. A composition according to any one of the preceding claims
wherein the total amount of second structuring material is from 1%
to 9% by weight of the composition.
6. A composition according to any one of the preceding claims
wherein the second structuring material comprises from 3 to 8% of
wax which is solid at temperatures of 40 C. and below, but melts
below 90 C.
7. A composition according to claim 5 wherein the second
structuring material comprises from 1% to 6% by weight of the
composition of structurant which forms a network of fibres and/or
from 3% to 7% by weight of the composition of said wax.
8. A composition according to any one of the preceding claims
wherein the organic polymeric thickener comprises from 2% to 7% by
weight of the composition of a polysaccharide esterified with a
monocarboxylic acid of 8 to 22 carbon atoms.
9. A composition according to any one of claims 1 to 7 wherein the
organic polymeric thickener comprises from 3 to 12% by weight of
the composition of a polymer selected from the group consisting of
polyamides and hydrocarbon polymers.
10. A composition according to any one of claims 1 to 7 wherein the
organic polymer thickener comprises from 2 to 12% by weight of the
composition of a co-polymer of vinyl pyrrolidone and polymethylene
blocks which contain at least 25 methylene units.
11. A composition according to one of the preceding claims
characterised in that the water-immiscible liquid contains a
volatile silicone and optionally a non-volatile silicone and/or a
non-silicone hydrophobic organic liquid selected from hydrocarbons,
hydrophobic aliphatic esters, aromatic esters and hydrophobic
alcohols.
12. A composition according to any one of the preceding claims
wherein the water-immiscible liquid contains volatile silicone oil
in an amount which is at least 10% by weight of the
composition.
13. A composition according to any one of the preceding claims
wherein the water-immiscible liquid comprises an alkyl benzoate,
preferably in a proportion of up to 80% by weight thereof.
14. A composition according to any one of the preceding claims
wherein the antiperspirant active comprises an aluminium and/or
zirconium halohydrate, an activated aluminium and/or zirconium
halohydrate, or an aluminium and/or zirconium complex or an
activated aluminium and/or zirconium complex.
15. A composition according to claim 14 wherein the antiperspirant
active comprises a halohydrate or complex in which aluminium and
zirconium are both present.
16. A composition according to any one of the preceding claims
wherein the proportion of antiperspirant active is from 5 to 40% by
weight of the composition.
17. An antiperspirant product comprising a dispensing container
having at least one aperture for outflow of the contents of the
container and a composition according to any one of the preceding
claims accommodated within the container.
18. A product according to claim 17 wherein the container has user
operable parts for urging the contents of the container through its
said outflow apertures.
19. A method of making a composition according to any one of the
preceding claims, comprising: mixing the ingredients of the
composition and, before or after complete mixing, heating the
ingredients of the composition to a temperature at which continuous
phase is a mobile liquid in which the organic polymer thickener (i)
and the second structuring material (ii) are dissolved in the
water-immiscible liquid, introducing the composition, at a
temperature at which it is mobile, into containers, causing or
allowing further cooling of the containers until the temperature of
the composition in the containers has fallen below 30 C.
20. A method for preventing or reducing perspiration on human skin
comprising topically applying to the skin a composition according
to any one of claims 1 to 16.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to soft solid antiperspirant
compositions for application to human skin, especially the
axilla.
BACKGROUND OF THE INVENTION AND SUMMARY OF PRIOR ART
[0002] Antiperspirant compositions are widely used in order to
enable their users to avoid or minimise wet patches on their skin,
especially in axillary regions. A variety of these compositions
make use of a thickened or structured liquid which is applied to
the surface of the skin and serves as a carrier for the
antiperspirant active. In many such compositions the liquid is
water-immiscible and is thickened or structured by one or more
materials incorporated into the composition for that purpose.
[0003] Antiperspirant formulations have been provided with a range
of different product forms. One of these is a so-called "stick"
which is usually a bar of an apparently firm solid material held
within a dispensing container and which retains its structural
integrity and shape whilst being applied. Another possibility is a
softer solid composition accommodated in a dispensing container
which in use extrudes the composition through one or more
apertures.
[0004] The present invention is concerned with such soft solid
compositions. Such compositions have sufficient rigidity that they
are not observed by the human eye to flow, but they are deformable
by hand pressure and can be extruded from a container through one
or more apertures at the end of the container.
[0005] For use a small amount of the composition is extruded from
the container, which may then be used as an applicator to spread
the extruded material on the skin.
[0006] A number of properties of such compositions are significant.
The composition should be stable and not leak from its container
until deliberately extruded. Its sensory feel when applied should,
desirably, not be sticky. The applied film of the composition
preferably is of a transparent or translucent appearance rather
than an opaque white. This property is referred to as low visible
residue, and it is desirable in order that the deposit on the
user's skin is not easily seen. Moreover, this also avoids
conspicuous marks on clothing, to which the deposited material can
accidentally transfer.
[0007] Soft solid antiperspirant compositions have been marketed.
One commercial product used inorganic silica to thicken a carrier
liquid. Some products currently on the market use mixtures of waxes
to thicken a hydrophobic carrier liquid mixture. Such a formulation
requires some complexity in its production process and careful
control of temperature and other parameters at which the
composition is put into containers for retail sale. The existing
products structured with mixtures of waxes display some
syneresis--that is to say weeping of liquid from the body of the
composition.
[0008] Soft solid antiperspirant compositions with a continuous
phase provided by water-immiscible liquid have also been disclosed
in U.S. Pat. No. 5,635,165 (Panitch/Helene Curtis). The teaching of
this document is that the structuring of antiperspirant
compositions can be accomplished using either a sterol, such as
lanosterol or a starch hydrolysate ester, such as dextrin
palmitate.
[0009] The document states that to achieve the full advantage of
its invention, a fatty alcohol should be included in an amount from
1 to 15% by weight of the composition, to adjust firmness and
increase phase stability.
[0010] The examples in this document show two approaches to
formulation. One is to use dextrin palmitate alone, or sterols
alone, in an amount of 8% or more by weight of the composition. The
alternative approach is to use a much smaller amount of such
structuring agent accompanied by a larger amount of a fatty alcohol
which is solid at room temperature of 20 C. One example [Ex 6] uses
1% dextrin palmitate with 2.8% sucrose distearate and 5.7% behenyl
alcohol. Another example [Ex 16] uses 1% of a mixture of lanosterol
and dihydrolanosterol, together with 1.25% sucrose distearate and
10% of behenyl alcohol. This document does not attempt to use
lanosterol/dihydro-lanosterol jointly with dextrin palmitate and we
have found that it would be impossible to do so.
Lanosterol/dihydrolanost- erol gives unstable compositions except
with a restricted selection of carrier liquids (this is the subject
of a copending application) but these liquids are such poor
solvents for dextrin palmitate that it cannot be used to thicken
them.
[0011] The thickening of organic liquids with polyamides in order
to make antiperspirant compositions has been disclosed in U.S. Pat.
No. 5,500,209. Typically, compositions exemplified in this document
are thickened with 15% or more of thickening polymer, and are
emulsions in which the antiperspirant active is dissolved in water
or hydrophilic solvent.
[0012] U.S. Pat. No. 5,846,520 (Procter & Gamble) discloses
compositions structured with a 12-hydroxystearic acid as a gelling
agent. The document acknowledges that soft solid compositions may
be made, although it prefers (and exemplifies) firm sticks. The
document mentions possible optional components including waxes and
fatty acid esters to be used in small percentages as nucleating
agents.
[0013] 12-hydroxystearic acid (12-HSA) is an example of materials
which cause gelation by forming a network of fibres within the
composition as it cools from a heated state during processing.
[0014] These materials can be used to make rigid sticks, as taught
in U.S. Pat. No. 5,846,520 and other documents. However, we have
found that if such a structurant is used to make a soft solid, the
viscosity or hardness of the soft solid composition is very
sensitive to small changes in the concentration of gelling agent,
which is a potential difficulty when scaling up to commercial
production. Also, complex processing is required similar to that
required in making existing wax-structured soft solid products.
[0015] U.S. Pat. No. 5,480,637 (Dow Corning) used 12-hydroxystearic
acid, together with an alkyl siloxane polymer or copolymer as a
gelating system in order to produce solid products described as
"firm" and "rigid". The examples use a range of alkyl methyl
siloxane polymers but always at a concentration of only 1% by
weight of the composition.
SUMMARY OF THE INVENTION
[0016] We have now found that advantageous soft solid
antiperspirant compositions can be prepared by using a combination
of a polymeric thickener and a second structurant in specified
amounts which overall predominate over the amount (if any) of fatty
alcohol which is solid at room temperature of 20.degree. C.
[0017] Therefore, in a first aspect, this invention provides a soft
solid antiperspirant composition having a continuous phase which
contains water-immiscible liquid, and contains:
[0018] i) 1.5 to 15%, preferably 1.5 to 10% by weight of the
composition, of an organic polymeric thickener which is effective
to increase the viscosity of the water-immiscible liquid;
[0019] ii) 0.5 to 15%, preferably 0.5 to 10%, by weight of the
composition, of second structuring material selected from the group
consisting of
[0020] a) structurant which forms a network of fibres within the
continuous phase,
[0021] b) waxes, other than fatty alcohols, which are solid at
temperatures of 30.degree. C. and below, but melt below 95.degree.
C., and
[0022] c) mixtures thereof; and a particulate antiperspirant active
in suspension in said continuous phase.
[0023] It will be appreciated that compositions according to this
invention contain at least two materials serving to
thicken/structure the composition.
[0024] In many instances the total amount of the organic polymeric
thickener and second structuring material will be greater than the
total amount of any fatty alcohol which is solid at 20.degree.
C.
[0025] If structurant (a) which forms a network of fibres within
the continuous phase is present, the amount of it will generally be
from 0.5 to 7% by weight of the composition.
[0026] If wax (b) is present the amount of it will generally be
from 0.5 to 15% by weight of the composition.
[0027] A composition of this invention will generally be marketed
in a container by means of which it can be applied at time of use.
This container may be of conventional type.
[0028] A second aspect of the invention therefore provides an
antiperspirant product comprising a dispensing container having at
least one aperture for outflow of the contents of the container and
a composition of the first aspect of the invention in the
container. The aperture or apertures for outflow from the container
will normally be of smaller cross section than the container. Means
for urging the contents of the container to the said aperture or
apertures, for flow through them, may be moving parts operable by
the user or may simply be flexible container walls so that the user
can expel composition from the container by squeezing it.
[0029] Compositions embodying the present invention can provide one
or more of several advantages, and avoid disadvantages observed
with other structuring systems.
[0030] The viscosity enhancing effect of the second structuring
material is reduced markedly when the composition is applied. The
thickening effect of the polymer is not altered so much at the time
of application.
[0031] It is possible to formulate compositions which have adequate
firmness while in a container prior to use, but which also have
adequate mobility while being applied to skin. Moreover, the
compositions can feel less sticky than compositions with a
different thickening system.
[0032] By using this combination of organic polymeric thickener and
other structuring material, it is possible to achieve a good
combination of structural properties with a composition that gives
only a low visible residue on skin and, also important, on clothing
to which the composition may be accidentally transferred.
[0033] There is no necessity to incorporate any fatty alcohol which
is solid at room temperature. Preferably such fatty alcohol is
excluded or used only at low concentrations, since it is known to
crystallize as relatively large platelets and increase the opacity
and visibility of deposits.
[0034] A further advantage is simplicity of manufacture. The
compositions of this invention can be made and packed by heating
their constituents to form a liquid composition, mixing at
temperatures where the composition is freely mobile, putting the
composition into containers for retail sale and cooling or allowing
these compositions to cool to room temperature. There is no need
for continued stirring while the composition is thickening as it
cools, and the temperature at which the composition is put into the
containers is less critical.
[0035] Therefore in a third aspect, this invention provides a
method of making a composition as specified above, by steps of
mixing the ingredients of the composition, and before or after
complete mixing, heating the ingredients of the composition to a
temperature at which the continuous phase is a mobile liquid in
which the organic polymer thickener (i) and the second structuring
material (ii) are dissolved, followed by introducing the
composition, at a temperature at which it is mobile, into
containers, and causing or allowing cooling of the containers,
until the temperature of the composition in the containers has
fallen below 30.degree. C.
[0036] According to a fourth aspect of the present invention, there
is provided a method for preventing or reducing perspiration on
human skin comprising topically applying to the skin a composition
as specified in the first aspect of this invention.
DETAILED DESCRIPTION AND EMBODIMENTS
[0037] As mentioned above, the invention requires both an organic
polymeric thickener and another structurant within a
water-immiscible liquid phase in which a particulate solid
antiperspirant is suspended. Other materials may also be present
depending on the nature of the composition. The various materials
will now be discussed by turn and preferred features and
possibilities will be indicated.
Water-immiscible Liquid
[0038] The water-immiscible liquid comprise one or a mixture of
materials which are relatively hydrophobic so as to be immiscible
in water. Some hydrophilic liquid may be included, provided the
overall liquid mixture is immiscible with water. Generally, this
liquid or liquid mixture (when in the absence of polymeric
thickener or other structurant) will be freely mobile at
temperatures of 15 C. and above. It may have some volatility but
its vapour pressure will generally be less than 4 kPa (30 mmHg) at
25.degree. C. so that the material can be referred to as an oil or
mixture of oils. More specifically, it is desirable that at least
80% by weight of the liquid should consist of materials with a
vapour pressure not over this value of 4 kPa at 25.degree. C.
[0039] It is preferred that the liquid or liquid mixture includes a
volatile liquid silicone, i.e. liquid polyorganosiloxane. To class
as "volatile" such material should have a measurable vapour
pressure at 20 or 25.degree. C. Typically the vapour pressure of a
volatile silicone lies in a range from 1 or 10 Pa to 2 kPa at
25.degree. C.
[0040] It is desirable to include volatile silicone because it
gives a "drier" feel to the applied film after the composition is
applied to skin.
[0041] Volatile polyorganosiloxanes can be linear or cyclic or
mixtures thereof. Preferred cyclic siloxanes include
polydimethylsiloxanes and particularly those containing from 3 to 9
silicon atoms and preferably not more than 7 silicon atoms and most
preferably from 4 to 6 silicon atoms, otherwise often referred to
as cyclomethicones. Preferred linear siloxanes include
polydimethylsiloxanes containing from 3 to 9 silicon atoms. The
volatile siloxanes normally by themselves exhibit viscosities of
below 10.sup.-5 m.sup.2/sec (10 centistokes), and particularly
above 10.sup.-7 m.sup.2/sec (0.1 centistokes), the linear siloxanes
normally exhibiting a viscosity of below 5.times.10.sup.-6
m.sup.2/sec (5 centistokes). The volatile silicones can also
comprise branched linear or cyclic siloxanes such as the
aforementioned linear or cyclic siloxanes substituted by one or
more pendant --O--Si(CH.sub.3).sub.3 groups. Examples of
commercially available silicone oils include oils having grade
designations 344, 345, 244, 245 and 246 from Dow Corning
Corporation; Silicone 7207 and Silicone 7158 from Union Carbide
Corporation; and SF1202 from General Electric.
[0042] The hydrophobic liquid employed in compositions herein can
alternatively or additionally comprise non-volatile silicone oils,
which include polyalkyl siloxanes, polyalkylaryl siloxanes and
polyethersiloxane copolymers. These can suitably be selected from
dimethicone and dimethicone copolyols. Commercially available
non-volatile silicone oils include Dow Corning 556.TM. and Dow
Corning 200.TM. series.
[0043] The water-immiscible liquid may contain from 0% to 100% by
weight of one or more liquid silicones. Preferably, there is
sufficient liquid silicone to provide at least 10%, better at least
15%, by weight of the whole composition. If silicone oil is used,
volatile silicone preferably constitutes from 20 to 100% of the
weight of the liquid or liquid mixture. In many instances, when a
non-volatile silicone oil is present, its weight ratio to volatile
silicone oil is chosen in the range of from 1:3 to 1:40.
[0044] Silicon-free hydrophobic liquids can be used instead of, or
more preferably in addition to liquid silicones. Silicon-free
hydrophobic organic liquids which can be incorporated include
liquid aliphatic hydrocarbons such as mineral oils or hydrogenated
polyisobutene, often selected to exhibit a low viscosity. Further
examples of liquid hydrocarbons are polydecene and paraffins and
isoparaffins of at least 10 carbon atoms. Although polyisobutene
and polydecene are polymeric in nature, they are mobile liquids at
room temperature of 20.degree. C. and do not cause thickening of
other hydrophobic oils.
[0045] Some hydrophobic aliphatic or aromatic esters are liquids
which may be used. These also may well be used as only part of a
liquid mixture.
[0046] Suitable aliphatic esters contain at least one long chain
alkyl group, such as esters derived from C.sub.1 to C.sub.20
alkanols esterified with a C.sub.8 to C.sub.22 alkanoic acid or
C.sub.6 to C.sub.10 alkanedioic acid. The alkanol and acid moieties
or mixtures thereof are preferably selected such that they each
have a melting point of below 20.degree. C. These esters include
isopropyl myristate, lauryl myristate, isopropyl palmitate,
diisopropyl sebacate and diisopropyl adipate.
[0047] Suitable liquid aromatic esters, preferably having a melting
point of below 20.degree. C., include fatty alkyl benzoates.
Examples of such esters include suitable C.sub.8 to C.sub.18 alkyl
benzoates or mixtures thereof.
[0048] As mentioned above, aliphatic alcohols which are solid at 20
C., such as stearyl alcohol are preferably absent or else present
in low concentration such as less than 5% by weight of the whole
composition since these lead to visible white deposits when a
composition is used.
[0049] However, aliphatic alcohols which are liquid at 20.degree.
C. may be employed. These include branched chain alcohols of at
least 10 carbon atoms such as isostearyl alcohol and octyl
dodecanol.
[0050] Silicon-free liquids can constitute from 0-100% of the
water-immiscible liquid, but it is preferred that silicone oil is
present and that the amount of silicon-free constituents preferably
constitutes up to 50 or 60% and in many instances from 20 to 60% by
weight of the liquid mixture.
Organic Polymeric Thickener
[0051] A number of organic polymers are effective to increase the
viscosity of hydrophobic liquids, although some polymers do not do
so.
[0052] A material which is suitable as an organic polymeric
thickener will generally possess the following characteristics:
[0053] i) it will contain residues of at least 5 (possibly many
more than 7) monomer units bonded together into a polymer chain
[0054] ii) it should dissolve on heating in water-immiscible
liquids, and specifically it must have a solubility of at least
1.5% by weight in the heated water-immiscible liquid of the
continuous phase;
[0055] iii) after heating to dissolve and cooling to 20.degree. C.,
it will increase the viscosity of the water-immiscible liquid of
the continuous phase, in the absence of other structurant, when
dissolved therein at the same concentration as in the formulation
of the invention.
[0056] Preferably, under these conditions, it will bring about a
viscosity increase of at least 100 mPa.sec, better at least 250
mPa.sec when viscosity is measured with a Brookfield viscometer
using a T-bar spindle at 10 rpm at 20.degree. C. The choice of a
type B, type C or type D T-bar spindle will depend on the viscosity
of the system being measured. Provided the spindle is appropriate
to provide a viscosity measurement it will enable determination of
an increase in viscosity brought about by the polymer.
[0057] An additional or alternative characterisation of a suitable
polymer is that it can thicken the water-immiscible liquid to a
viscosity of at least 10,000 mPa.sec, measured in the same way,
when incorporated in the water-immiscible liquid at 15% by weight,
in the absence of the other structurant.
[0058] The polymer will generally be solid at 20.degree. C. One
category of polymer which has been found suitable is a
polysaccharide esterified with monocarboxylic acid containing at
least 4 carbon atoms.
[0059] Preferred in this category is a dextrin fatty acid ester
having the formula: 1
[0060] wherein each R group, individually, is a hydrogen atom or an
acyl group having up to 22 carbon atoms, provided that at least one
R group per glucose unit is an acyl group of at least 4 carbon
atoms, and m has an average value from 5, 10 or 20 up to 50 or even
up to 150, more preferably from 20 to 30. The dextrin fatty acid
ester can be a partial ester, i.e. at least one R group is
hydrogen; or the dextrin can be completely esterified, i.e., all R
groups are acyl, such as a C.sub.4- C.sub.22 acyl group. The acyl
groups may be the same or similar, and preferably they are straight
chain acyl groups with chain lengths of 8 to 22 carbon atoms, e.g.
in a range from 12 or 14 carbon atoms to 18 or 20 carbon atoms.
Branched acyl groups may be included, possibly as in a mixture of
C.sub.6 to C.sub.22 linear acyl groups. Shorter acyl groups may
form part of a mixture, for example C.sub.4 to C.sub.8 acyl groups
may be mixed with C.sub.12 to C.sub.22 linear acyl groups. In
preferred embodiments, wherein the R group is a C.sub.8-C.sub.22
acyl group the degree of substitution is at least 2 (i.e., at least
two R groups are C.sub.8-C.sub.22 acyl groups).
[0061] The C.sub.8-C.sub.22 fatty acids that are reacted with the
starch hydrolyzate can be saturated or unsaturated acids, and
include, for example, capric acid, pelargonic acid, caprylic acid,
undecylic acid, undecylenic acid, lauric acid, myristic acid,
pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid,
nonadecanoic acid, arachidic acid, oleic acid, linoleic acid,
linolenic acid, similar acids, and mixtures thereof. These dextrin
fatty acid esters are disclosed in Mori et al U.S. Pat. No.
4,780,145, incorporated herein by reference, and some of them are
available under the trade name RHEOPEARL from Chiba Flour Milling
Co., Ltd., Japan. An example of a dextrin fatty acid ester is
dextrin palmitate, available commercially as RHEOPEARL KL and
RHEOPEARL FL, for example, from Chiba Flour Milling Co., Ltd. Other
examples of esters of C.sub.8-C.sub.22 carboxylic acids are dextrin
behenate, dextrin laurate, dextrin myristate, dextrin stearate, and
mixtures thereof.
[0062] A second category of polymer which can be used as a
thickener is polyamides as discussed in U.S. Pat. No. 5,500,209.
Such polyamides may be derived from organic diamines containing 2
to 12, preferably 2 to 8 carbon atoms, condensed with di- or poly
carboxylic acids containing 4 to 20 carbon atoms per carboxylic
acid group. Some monocarboxylic acid may be included in the
reaction mixture to control polymer chain length. The dicarboxylic
acids may be obtained by thermal polymerisation of unsaturated
monocarboxylic acids.
[0063] Such polyamides are available from Henkel under their trade
name VERSAMID. An example is VERSAMID 950 from hexamethylene
diamine and adipic acid.
[0064] A further category of polymer which has been found useful is
the block copolymers of styrene with ethylene, propylene and/or
butylene available from Shell under their trade name KRATON G.
[0065] Preferred in this category is styrene ethylene/butylene
styrene linear block copolymers e.g. that available as KRATON G
1726X.
[0066] Another suitable type of polymer is polymers of alpha
methylstyrene and styrene available from Hercules under the trade
name KRISTALEX. One suitable grade is KRISTALEX F85, with mean
molecular weight of approximately 1200.
[0067] A further class of polymers found to be suitable for use
with a second structurant comprises polyethylene having a molecular
weight of from 500, sometimes 2000, to 8000, such as materials
available from Quantum USI under the trade name MN 714.
[0068] A still further class of polymers found to be suitable
comprises co-polymers of vinyl pyrrolidone with polyethylene
containing at least 25 methylene units. A particularly suitable
polymer comprises triacontanyl polyvinylpyrrolidone, such as that
available from International Speciality Products under the trade
name Antaron WP-660.
[0069] Yet another polymer found to be suitable although less
preferred is alkyl substituted galactomannan available from
Hercules under their trade name N-HANCE AG.
[0070] The thickening ability of polymers varies from one to
another, which will affect the amount which is required. The amount
will often lie in a range from 2% or 3% by weight of the
composition up to 7% or more, such as to 10%, 12% or 15%.
Fibre-forming Structurant
[0071] A number of organic compounds are known to possess the
ability to gel hydrophobic organic liquids such as water-immiscible
hydrocarbon and/or silicone oils. Such materials are generally
monomers or dimers with molecular weight below 10,000 often below
5,000 or even 1,000 rather than polymers with more than four repeat
units or with molecular weight above 10,000.
[0072] Gel formation takes place as an exothermic event within a
temperature range referred to as the gel point; upon reheating,
melting of the gel takes place as an endothermic event within a
temperature range. Such gels can be disrupted by shearing. Although
a small partial recovery may then be observed, such gels do not
recover their structure for a long time, if at all, unless
remelted.
[0073] Materials with this ability to gel hydrophobic organic
liquids have been reviewed by Terech and Weiss in "Low Molecular
Mass Gelators of Organic Liquids and the Properties of their Gels"
Chem. Rev 97, 3133-3159 [1997] and by Terech in Chapter 8,
"Low-molecular weight Organogelators" of the book "Specialist
surfactants" edited by I D Robb, Blackie Academic Professional,
1997.
[0074] It is characteristic of such structurants, useful in this
invention, that:
[0075] if they are able to gel the organic liquid in the absence of
any disperse phase, when used in sufficient quantity not exceeding
15% by weight;
[0076] the structured liquids are obtainable by cooling from an
elevated temperature at which the structurant is in solution in the
liquid--this hot solution being mobile and pourable;
[0077] the (thus obtained) structured liquid becomes more mobile if
subjected to shear or stress;
[0078] the structure does not spontaneously recover within 24 hours
if the sheared liquid is left to stand at ambient laboratory
temperature, even though a small partial recovery may be
observed;
[0079] the structure can be recovered by reheating to a temperature
at which the structurant is in solution in the liquid and allowing
it to cool back to ambient laboratory temperature.
[0080] It appears that such structurants operate by interactions
which are permanent unless disrupted by shear or heating. Such
structurants form a network of strands or fibres extending
throughout the gelled liquid. In some cases these fibres can be
observed by electron microscopy, although in other cases the
observation of the fibres which are believed to be present is
prevented by practical difficulties in preparing a suitable
specimen. When observed, the primary fibres in a gel are generally
thin (diameter less than 0.5 .mu.m, often less than 0.2 .mu.m) and
appear to have numerous branches or interconnections. Primary
fibres may entwine to form a thicker strand.
[0081] If these fibres are crystalline, they may or may not be the
same polymorph as macroscopic crystals obtained by conventional
crystallization from a solvent.
[0082] One material which is well known to form such gels is
12-hydroxy stearic acid which is discussed in Terech et al
"Organogels and Aerogels of Racemic and Chiral 12-hydroxy
octadecanoic Acid", Langmuir Vol 10, 3406-3418, 1994. The material
is commercially available from Ajinomoto and also from Caschem.
[0083] U.S. Pat. No. 5,750,096 is one of several documents which
teaches that gelation can be brought about using esters or amides
of 12-hydroxy stearic acid. The alcohol used to form such an ester
or the amine used to form such an amide may contain an aliphatic,
cycloaliphatic or aromatic group with up to 22 carbons therein. If
the group is aliphatic it preferably contains at least three carbon
atoms. A cycloaliphatic group preferably contains at least five
carbon atoms and may be a fixed ring system such as adamantyl.
[0084] Other fatty acids with C.sub.8 or longer alkyl chains may be
used and amides thereof can also be used. A specific example is
lauric monoethanolamide also termed MEA lauramide:
[0085] N-acyl amino acid amides and esters are also known to
structure liquids. We have established that they do so by forming
fibrous networks. They are described in U.S. Pat. No. 3,969,087.
N-Lauroyl-L-glutamic acid di-n-butylamide is commercially available
from Ajinomoto under their designation GP-1.
[0086] Further materials which have been disclosed as gelling
agents are the amide derivatives of di and tribasic carboxylic
acids set forth in WO 98/27954 notably alkyl N,N'dialkyl
succinamides.
[0087] Lanosterol, as disclosed in U.S. Pat. No. 5,635,165
mentioned above may suitably be used if the water-immiscible liquid
is silicone oil and provided the polymeric thickener is
sufficiently soluble therein. Lanosterol has the following chemical
formula: 2
[0088] It is commercially available, e.g. from Croda Chemicals Ltd,
and as supplied it contains some dihydrolanosterol. This impurity
in the commercial material does not need to be removed.
[0089] A structurant which is the subject of a co-pending
application is a combination of a sterol and a sterol ester.
[0090] In its preferred form the sterol satisfies either of the two
formulae: 3
[0091] in which R represents an aliphatic, cycloaliphatic or
aromatic group, and preferably a linear or branched aliphatic
saturated or unsaturated hydrocarbon group. R desirably contains
from 1 to 20 carbons and preferably from 4 to 14 carbons.
[0092] It is particularly suitable to employ .beta.-sitosterol or
campesterol or cholesterol, or a hydrogenated derivative thereof,
such as dihydrocholesterol, or a mixture of two or more of them. An
especially preferred sterol .beta.-sitosterol.
[0093] The preferred sterol ester is oryzanol, sometimes referred
to as .gamma. oryzanol which contains material satisfying the
following formula: 4
[0094] The sterol and sterol ester are used in a mole ratio that is
normally selected in the range of from 10:1 to 1:10, especially
from 6:1 to 1:4 and preferably in the range of from 3:1 to 1:2.
Employment of the two system constituents within such a mole ratio
range, and especially within the preferred range facilitates the
co-stacking of the constituents and consequently facilitates the
formation of a network that is readily able to structure the
formulation.
[0095] Another structurant which is the subject of a co-pending
application and which may be used in this invention is an ester of
cellobiose and a fatty acid, preferably of 6 to 13 carbon atoms
especially 8 to 10 carbon atoms. Preferably the cellobiose is fully
esterified, or nearly so, and is in the .alpha.-anomeric form.
[0096] The structure of such a compound, in its a-anomeric form
is:
[0097] where R is an alkyl or alkenyl chain of 5 to 12 carbon atoms
so that the acyl group contains 6 to 13 carbon atoms. Particularly
preferred acyl groups incorporate a linear alkyl chain of 7 to 9
carbon atoms and are thus octanoyl, nonanoyl or decanoyl.
[0098] The acyl groups may have a mixture of chain lengths but it
is preferred that they are similar in size and structure. Thus it
is preferred that all of the acyl groups are aliphatic and at least
90% of the acyl groups have a chain length within a range such that
the shorter and longer chain lengths in the range differ by no more
than two carbon atoms, i.e. length in a range from m-1 to m+ 1
carbon atoms where m has a value in a range from 7 to 10.
[0099] Linear aliphatic acyl groups may be obtained from natural
sources, in which case the number of carbon atoms in the acyl group
is likely to be an even number or may be derived synthetically from
petroleum as the raw material in which case both odd and even
numbered chain lengths are available.
[0100] Synthetic methods for the esterification of saccharides are
well known. The esterification of cellobiose has been reported by
Takada et al in Liquid Crystals, (1995) Volume 19, pages 441-448.
This article gives a procedure for the production of the alpha
anomers of cellobiose octa-alkanoates by esterification of
.beta.-cellobiose using an alkanoic acid together with
trifluoracetic anhydride.
[0101] A further example of structurant which is the subject of a
co-pending application is compounds of the following general
formula (TI): 5
[0102] It is preferred that m is 2 so that the structurant
compounds comply with a general formula (T2): 6
[0103] The groups Y and Y.sup.1 will usually be identical, i.e.
both methylene or both carbonyl. The groups Q and Q.sup.1 may not
be the same but often will be identical to each other.
[0104] If m is 2 and Y and Y.sup.1 are methylene groups, the
compound is a derivative of threitol, which is
1,2,3,4-tetrahydroxybutane, while if m is 2 and Y and Y.sup.1 are
carbonyl groups, the compound is a diester of tartartic acid, which
is 2,3-dihydroxybutane-1,4-dioic acid.
[0105] It is preferred that each group Q and Q.sup.1 contains an
aromatic nucleus which may be phenyl or, less preferably, some
other aromatic group. Thus Q and Q.sup.1 may be groups of the
formula
Ar--(CH.sub.2).sub.n--
[0106] where Ar denotes an aromatic nucleus, notably phenyl or
substituted phenyl and n is from 0 to 10.
[0107] An aromatic nucleus (Ar) is preferably unsubstituted or
substituted with one or more substituents selected from alkyl,
alkyloxy, hydroxy, halogen or nitro.
[0108] One substituent may be an alkyl or alkyloxy group with a
long alkyl chain. Thus, a formula for preferred structurants of
this invention can be given as (T3): 7
[0109] where
[0110] n=0 to 10, preferably 0 to 3, more preferably 1, 2 or 3;
[0111] Y.dbd.--CH.sub.2-- or >C.dbd.O
[0112] X.sub.1.dbd.H, Cl, Br, F, OH, NO.sub.2, O--R, or R, where R
is an aliphatic hydrocarbon chain with 1 to 18 carbon atoms.
[0113] X.sub.2 to X.sub.5 are each independently H, Cl, Br, F, OH,
NO.sub.2, OCH.sub.3, or CH.sub.3
[0114] In these formulae above, the central carbon atoms which bear
hydroxy groups are chiral centres. Thus, if m=2, Y and Y.sup.1 are
the same and Q and Q.sup.1 are the same, the compounds will exist
as R,R and S,S optically active forms as well as an optically
inactive R,S form.
[0115] These compounds may be used as their optically active R,R or
S,S forms or as a mixture of the two--which may be a racemic
mixture.
[0116] Compounds within the general formula (TI) above are
available commercially. Also, syntheses of these compounds have
been given in scientific literature where the compounds were being
used as intermediates for purposes not related to the present
invention. Thus syntheses of threitol derivatives can be found
in:
[0117] Kataky et al, J. Chem Soc Perkin Trans vol 2 page 321 [1990]
Tamoto et al, Tetrahedron Vol 40 page 4617 [1984], and Curtis et
al, J. C. S. Perkin I Vol 15 page 1756 [1977]. Preparations of
tartrate esters are found at: Hu et al J. Am. Chem. Soc. Vol 118,
4550 [1996] and Bishop et al J. Org Chem Vol56 5079 [1991].
Waxes
[0118] This term "wax" is conventionally applied to a variety of
materials and mixtures which have similar physical properties,
namely that:
[0119] they are solid at 30.degree. C. and preferably also at
40.degree. C.;
[0120] they melt to a mobile liquid at a temperature above
30.degree. C. but generally below 95.degree. C. and preferably in a
temperature range of 40.degree. C. to 90.degree. C.;
[0121] they are water-insoluble and remain water-immiscible when
heated above their melting point.
[0122] Waxes are usually hydrocarbons, silicone polymers, esters of
fatty acids or mixtures containing such compounds along with a
minority (less than 50%) of other compounds. Naturally occurring
waxes are often mixtures of compounds which include a substantial
proportion likely to be a majority of fatty esters.
[0123] Waxes form crystals in the water-immiscible liquid when it
cools from the heated state during processing.
[0124] These crystals take various forms including needles and
platelets depending on the individual waxes. Some waxes form a
network of fibrous crystals and can therefore also be identified as
fibre-forming structurants.
[0125] Examples of hydrocarbon waxes include paraffin wax,
microcrystalline wax and polyethylenes with molecular weight of 500
to 10,000, often 2000 to 10,000.
[0126] Examples of ester waxes include esters of C.sub.16-C.sub.22
fatty acids with glycerol or ethylene glycol and these may be made
synthetically.
[0127] Examples of natural waxes include beeswax, carnauba and
candelilla waxes which are of vegetable origin and mineral waxes
from fossil remains other than petroleum. Montan wax, which is an
example of mineral wax, includes non-glyceride esters of carboxylic
acids, hydrocarbons and other constituents.
[0128] Waxes useful in the present invention will generally be
those found to thicken water-immiscible oils such as
cyclomethicones when dissolved therein (by heating and cooling) at
a concentration of 5 to 15% by weight.
[0129] If a wax is used which forms a network of fibres, the amount
of it may be from 0.5 to 7% by weight of the composition. If a wax
is used which does not form such a network, for instance a wax
which crystallizes as spheralitic needles or as small platelets,
the amount may well be from 2% or 3% up to 10%, 12& or 15% of
the composition. Silicone waxes are an example of waxes which
crystallize as small platelets.
[0130] The total amount of second structurant may range from 0.5%
or 1% of the composition up to 9%, 10% or 15%.
[0131] The ratio of polymer to second structurant can vary
considerably but in many instances it will lie in a range from 6:1
to 1:4.
[0132] In a number of embodiments the composition will contain 0.5
to 10% or 15% polymeric thickener, 0.5 to 7% of fibre-forming
structurant and 2% to 10% of a wax such as silicone wax which does
not crystallize as a network of fibres, all these percentages being
by weight of the composition.
[0133] Some polymers, notably some polyethylenes have melting
characteristics such that they will satisfy the definition of a
wax. It is possible, within the scope of this invention for such a
polymer to be present accompanied by a fibre-forming structurant
and/or another wax. It is also possible for such a polymer to be
present as a wax, when some other polymer is present.
Antiperspirant Actives
[0134] The composition will contain a particulate antiperspirant
active. Antiperspirant actives are preferably incorporated in an
amount of from 0.5-60%, particularly from 5 to 30% or 40% and
especially from 5 or 10% to 30 or 35% of the weight of the
composition.
[0135] Antiperspirant actives for use herein are often selected
from astringent active salts, including in particular aluminium,
zirconium and mixed aluminium/zirconium salts, including both
inorganic salts, salts with organic anions and complexes. Preferred
astringent salts include aluminium, zirconium and
aluminium/zirconium halides and halohydrate salts, such as
chlorohydrates.
[0136] Aluminium halohydrates are usually defined by the general
formula Al.sub.2(OH).sub.xQ.sub.y.wH.sub.2O in which Q represents
chlorine, bromine or iodine, x is variable from 2 to 5 and x+y=6
while wH.sub.2O represents a variable amount of hydration.
Especially effective aluminium halohydrate salts, known as
activated aluminium chlorohydrates, are described in EP-A-6739
(Unilever NV et al), the contents of which specification is
incorporated herein by reference.
[0137] Zirconium actives can usually be represented by the
empirical general formula: ZrO(OH).sub.2n-nzB.sub.z.wH.sub.2O in
which z is a variable in the range of from 0.9 to 2.0 so that the
value 2n-nz is zero or positive, n is the valency of B, and B is
selected from the group consisting of chloride, other halide,
sulphamate, sulphate and mixtures thereof. Possible hydration to a
variable extent is represented by wH20. Preferable is that B
represents chloride and the variable z lies in the range from 1.5
to 1.87. In practice, such zirconium salts are usually not employed
by themselves, but as a component of a combined aluminium and
zirconium-based antiperspirant.
[0138] The above aluminium and zirconium salts may have coordinated
and/or bound water in various quantities and/or may be present as
polymeric species, mixtures or complexes. In particular, zirconium
hydroxy salts often represent a range of salts having various
amounts of the hydroxy group. Zirconium aluminium chlorohydrate may
be particularly preferred.
[0139] Antiperspirant complexes based on the above-mentioned
astringent aluminium and/or zirconium salts can be employed. The
complex often employs a compound with a carboxylate group, and
advantageously this is an amino acid. Examples of suitable amino
acids include dl-tryptophan, dl-phenylalanine, dl-valine,
dl-methionine and -alanine, and preferably glycine which has the
formula CH.sub.2(NH.sub.2)COOH.
[0140] It is highly desirable to employ complexes of a combination
of aluminium halohydrates and zirconium chlorohydrates together
with amino acids such as glycine, which are disclosed in U.S. Pat.
No. 3,792,068 (Luedders et al). Certain of those Al/Zr complexes
are commonly called ZAG in the literature. ZAG actives generally
contain aluminium, zirconium and chloride with an Al/Zr ratio in a
range from 2 to 10, especially 2 to 6, an Al/Cl ratio from 2.1 to
0.9 and a variable amount of glycine. Actives of this preferred
type are available from Westwood, from Summit and from Reheis.
[0141] Other actives which may be utilised include astringent
titanium salts, for example those described in GB 2299506A.
[0142] The proportion of solid antiperspirant salt in a composition
normally includes the weight of any water of hydration and any
complexing agent that may also be present in the solid active.
[0143] The particle size of the antiperspirant salts often falls
within the range of 0.1 to 200 .mu.m with a mean particle size
often from 3 to 20 .mu.m. Both larger and smaller mean particle
sizes can also be contemplated such as from 20 to 50 .mu.m or 0.1
to 3 .mu.m.
Optional Ingredients
[0144] Optional ingredients in compositions of this invention can
include deodorants, for example at a concentration of up to about
10% w/w. Suitable deodorant actives can comprise deoperfumes,
and/or microbicides, including particularly bactericides, such as
chlorinated aromatics, including biguanide derivatives, of which
materials known as Triclosan e.g. Igasan DP300.TM., Tricloban.TM.,
and Chlorhexidine warrant specific mention. A yet another class
comprises biguanide salts such as those available under the trade
mark Cosmosil.TM..
[0145] Other optional ingredients include wash-off agents, often
present in an amount of up to 10% w/w to assist in the removal of
the formulation from skin or clothing. Such wash-off agents are
typically nonionic surfactants such as esters or ethers containing
a C.sub.8 to C.sub.22 alkyl moiety and a hydrophilic moiety which
can comprise a polyoxyalkylene group (POE or POP) and/or a
polyol.
[0146] The compositions herein can incorporate one or more cosmetic
adjuncts conventionally envisaged for antiperspirant soft solids.
Such cosmetic adjuncts can include skin feel improvers, such as
clays, silica, talc or finely divided polyethylene, for example in
an amount of up to about 10%; skin benefit agents such as glycerol,
allantoin or lipids, for example in an amount of up to 5%; skin
cooling agents other than the already mentioned alcohols, such a
menthol and menthol derivatives, often in an amount of up to 2%,
all of these percentages being by weight of the composition. A
commonly employed adjunct is a perfume, which is normally present
at a concentration of from 0 to 4% and in many formulations from
0.25 to 2% by weight of the composition.
Product Packages
[0147] A composition of this invention will usually be marketed as
a product comprising a container with a quantity of the composition
therein, where the container has at least one aperture for the
delivery of composition, and means for urging the composition in
the container towards the delivery aperture(s). Conventional
containers take the form of a barrel of oval cross section with an
apertured part at one end of the barrel.
[0148] Generally the container will include a cap to go over that
apertured end part and a component part which is sometimes referred
to as an elevator or piston fitting within the barrel and capable
of relative axial movement along it. The composition is
accommodated in the barrel between the piston and the apertured
part on the barrel. The piston is used to urge the body of
composition along the barrel. The piston and stick of composition
may be moved axially along the barrel by manual pressure on the
underside of the piston using a finger or rod inserted within the
barrel. Another possibility is that a rod attached to the piston
projects through a slot or slots in the barrel and is used to move
the piston and stick. Preferably the container also includes a
transport mechanism for moving the piston comprising a threaded rod
which extends axially into the body of the composition through a
correspondingly threaded aperture in the piston, and means mounted
on the barrel for rotating the rod. Conveniently the rod is rotated
by means of a handwheel mounted on the barrel at its closed end,
i.e. the opposite end to the delivery opening.
[0149] The apertured part at one end of the barrel is normally a
closure with one or more apertures through which composition from
the barrel can be extruded. The number and design of such apertures
is at the discretion of the designer of the package.
[0150] The component parts of such containers are often made from
thermoplastic materials, for example polypropylene or polyethylene.
Descriptions of suitable containers, some of which include further
features, are found in U.S. Pat. Nos. 4,865,231, 5,000,356 and
5,573,341.
Preparation
[0151] Compositions of this invention can be produced by
conventional processes for making suspension solids or soft-solids.
Such processes involve forming a heated mixture of the composition
at a temperature which is sufficiently elevated that all the
polymer and other structurant dissolves, introducing that mixture
into a mould, which may be a dispensing container, and then
allowing the mixture to cool.
[0152] A convenient process sequence for a composition, which is a
suspension, comprises first forming a solution of the polymer and
other structurant in the water-immiscible liquid or liquid mixture.
This is normally carried out by agitating the mixture at a
temperature sufficiently high that all the structurant dissolves
(the dissolution temperature) such as a temperature in a range from
50 to 150.degree. C. Thereafter the particulate constituent, for
example particulate antiperspirant active, is blended with the hot
mixture. This must be done slowly, or the particulate solid must be
preheated, in order to avoid premature gelation. The resulting
blend is then introduced into a dispensing container such as a
stick barrel. This is usually carried out at a temperature 5 to
30.degree. C. above the setting temperature of the composition. The
container and contents are then cooled to ambient temperature.
Cooling may be brought about by nothing more than allowing the
container and contents to cool. Cooling may be assisted by blowing
ambient or even refrigerated air over the containers and their
contents.
Measurement of Properties
[0153] i) Texture analyser
[0154] This test apparatus can move a blunt probe into or out from
a sample at a controlled speed and at the same time measure the
applied force. The parameter which is determined as hardness is a
function of the force and the projected area of indentation.
[0155] A specific test protocol used a Stable Micro systems
TA.XT2I.TM. Texture Analyser. A sample of composition was made by
heating the ingredients, pouring into a container and allowing to
cool as described above. The container was a 15 ml glass jar with a
wide mouth. A metal sphere, of diameter 9.5 mm, was attached to the
underside of the Texture Analyser's 5 kg load cell such that it
could be used for indenting a sample placed beneath it on the base
plate of the instrument. After positioning the sample, the sphere
position was adjusted until it was just above the sample surface.
Texture Expert Exceed.TM. software was used to generate the
subsequent motion profile used in the test method. This profile
initially moved the sphere into contact with the sample and then
indented the sphere into the sample at an indentation speed of 0.05
mm/s for a distance of 7 mm. At this distance the direction of
motion of the sphere was immediately reversed to withdraw the
sphere from the sample at the same speed of 0.05 mm/s. During the
course of the test, the data acquired were time(s), distance (mm)
and force (N) and the data acquisition rate was 25 Hz.
[0156] The data associated with each test were manipulated using
standard spreadsheet software and used to calculate the hardness,
H, at a travelled distance of 4.76 mm after initial contact with
the sample, using the following equation:
H=F/A
[0157] (H expressed in N.mm.sup.-2 , F in N and A in mm.sup.-2)
where F is the load at the same travelled distance and A is the
projected area of the indentation. This area can be calculated
geometrically and is equal to the area of a diametral plane of the
sphere, i.e. .pi..times.(4.76).sup.2 mm.sup.2.
[0158] For a soft solid composition the measured hardness H will
generally be from 0.003 to 0.5 N/mm.sup.2. Frequently, the hardness
will be from 0.003 up to 0.1 N/mm.sup.2.
[0159] ii) Whiteness of deposit
[0160] Another test of the properties of a composition is the
whiteness and hence opacity of the composition which is delivered
onto a surface when the composition is drawn across that surface
(representing the application of the composition to human skin). To
carry out this test of deposition, a sample of the composition was
first applied to a test fabric under standardised conditions.
[0161] The test fabric was a rectangular strip of black worsted
wool fabric 9 cm by 15 cm. This was placed in an apparatus
consisting of a metallic base onto which was hinged a metallic
frame defining a rectangular aperture of 5 cm by 9 cm. The test
portion of fabric was laid on the base. The hinged frame was placed
over the fabric and secured to the base by means of two screws
thereby clamping the test fabric in place but exposing an area of
5.times.9 cm through the aperture.
[0162] A sample of soft solid composition in a dispensing container
was kept at ambient laboratory temperature (about 20 C.) before it
was required for measurement. A portion of the composition is then
extruded from the container through the dispensing apertures at one
end. A weight amount (0.51 g) of the extruded composition was
spread uniformly across the 5.times.9 cm area of test fabric
enclosed by the frame. Spreading was carried out using a plastic
spreading tool. After spreading the sample of composition on the
fabric substrate, it was removed from the apparatus and weighed to
check that the mass of applied sample was 0.5.+-.0.01 gms.
[0163] The fabric with applied sample of composition was then
assessed twice for whiteness, once after one hour and again after
24 hours.
[0164] This measurement was carried out using a Sony XC77.TM.
monochrome video camera with a Cosmicar.TM. 16 mm focal length lens
positioned vertically above a black table illuminated from a high
angle using fluorescent tubes to remove shadowing. The apparatus
was initially calibrated using a reference white card, after the
fluorescent tubes had been turned on for long enough to give a
steady light output. The cloth with a deposit thereon was placed on
the table and the camera was used to capture an image. An area of
the image of the deposit was selected and analysed using a Kontron
IBAS.TM. image analyser. This notionally divided the image into a
large array of pixels and measured the grey level of each pixel on
a scale of 0 (black) to 255 (white). The average of the grey
intensity was calculated. This was a measure of the whiteness of
the deposit, with higher numbers indicating a whiter deposit. It
was assumed that low numbers show a clear deposit allowing the
substrate colour to be seen. All samples were prepared in
triplicate and a mean of the three measured values was
reported.
[0165] The above test procedures were applied to two soft solid
compositions currently marketed commercially. An existing product
structured with castor wax and a silicone wax had a hardness
measured by texture analyser of 0.0231, a whiteness measurement
after 1 hour of 23 and a whiteness measurement after 24 hours of
42. A competitor's product, believed also to have a wax structuring
system, had a hardness of 0.0318, a whiteness measurement after 1
hour of 20 and a whiteness measurement after 24 hours of 83.
EXAMPLES
[0166] The examples and comparative examples set out in the series
of tables below were prepared using a number of materials whose
suppliers and some other details are given in the following list.
Throughout these tables, the amounts of the materials are
percentages by weight.
[0167] 1. Dextrin palmitate (Rheopearl.TM. KL) from Chiba Flour
Milling Co. under their trademark
[0168] 2. Silicone wax (SF1642.TM.) from General Electric Inc
[0169] 3. Silicone wax (SF1632.TM.) from General Electric Inc
[0170] 4. Silicone wax (DC X2-2493.TM.) from Dow Corning Inc
[0171] 5. Silicone wax (1205-04-261) from General Electric
[0172] 6. Silicone wax (Abilwax.TM. 9810) from Goldschmidt
[0173] 7. Silicone wax (AMS-C30.TM.) from Dow Corning Inc
[0174] 8. Volatile cyclic silicone (cyclomethicone) (DC 345.TM.)
from Dow Corning
[0175] 9. C.sub.12-.sub.15 alkylbenzoate (Finsolv.TM. TN) from
Finetex
[0176] 10. Al/Zr Tetrachlorohydrex glycine complex (AZAG-7167.TM.)
from Summit
[0177] 11. Isopropyl palmitate (Estol.TM. 1517) from Unichema
[0178] 12. Isostearyl alcohol (Prisorene.TM. 3515) from
Unichema
[0179] 13. Castorwax MP80.TM. from Caschem
[0180] 14. Beeswax ester K62.TM. from Koster Keunen
[0181] 15. C.sub.18-C.sub.36 fatty acid triglyceride, available as
Syncrowax.TM. HGLC from Croda Chemicals
[0182] 16. Behenic acid triglyceride, available as Syncrowax.TM.
HRC from Croda Chemicals
[0183] 17. Ethylene-vinyl acetate copolymer AC 400.TM. from Allied
Sigma
[0184] 18. Victory amber wax (a wax of vegetable origin) from
Bareco
[0185] 19. MN 714.TM. from Quantum USI
[0186] 20. Polypropyleneglycol-14-butylether (Fluid.TM. AP) from
Union Carbide
[0187] 21. Isohexadecane, available as Permethyl.TM. 101A from
Presperse
[0188] 22. Mackamide.TM. (stearyl monoethanolamide) from McIntyre
Group
[0189] 23. Mackamide.TM. LMM (lauryl monoethanolamide) from
McIntyre Group
[0190] 24. Eutanol.TM. G from Henkel
[0191] 25. 12-HSA from Caschem
[0192] 26. .beta.-sitosterol from Kaukas
[0193] 27. Oryzanol from Jan Dekker
[0194] 28. N-Lauroyl-glutamic acid di-n-butylamide, available as
GP-1.TM. from Ajinomoto
[0195] 29. C.sub.18-C.sub.36 fatty acid glycol ester, available as
Syncrowax.TM. ERLC from Croda Chemicals
[0196] 30. Kristalex F85 Hydrocarbon resin from Hercules
[0197] 31. N-Hance AG 50.TM. alkyl substituted galactomannan from
Hercules
[0198] 32. Kraton.TM. G 1726 block copolymer from Shell
[0199] 33. Versamid.TM. 930 polyamide from Henkel
[0200] 34. Suprafino.TM. A talc (particle size about 5 ) from
Cyprus Minerals
[0201] 35. Polyethylene beads, available as Acumist.TM. B9 from
Allied Sigma
[0202] 36. Polyethylene beads, available as Acumist.TM. C9 from
Allied Sigma
[0203] 37. Microcrystalline wax, available as Permulgin.TM. 4201
from Koster Keunen
[0204] 38. Volatile cyclic silicone (cyclomethicone) DC 245.TM.
from Dow Corning
[0205] 39. Triacontenyl vinyl pyrrolidone copolymer, available as
Antaron.TM. WP-660 from ISP.
[0206] The following general method of preparation was used for
these examples. A solution of the thickening polymer and other
structurants in the organic liquid(s) was made by mixing these
materials, heating and agitating the mixture at a temperature
sufficiently high that the polymer and other structurants all
dissolve. The mixture was then allowed to cool to 80-85.degree. C.
before the aluminium-containing antiperspirant active was added.
The mixture was next allowed to cool to 5-20.degree. C. above its
gelling temperature (determined in a preliminary experiment) and
poured into dispensing containers for soft solids. These were then
left to cool to room temperature.
[0207] The procedure was varied slightly in two instances. If GP-1
was used, it was first dissolved in the hot liquid mixture after
which the thickening polymer and any other structurants were added
and dissolved. If .beta.-sitosterol and oryzanol were used in
combination as structurant, the oryzanol was first dissolved in the
hot liquid mixture followed by addition and dissolution of the
thickening polymer, .beta.-sitosterol and any other structurants.
In both of these variations, the general procedure then continued
as stated above with cooling to 80-85.degree. C. for addition of
the antiperspirant active, further cooling to 5-20.degree. C. above
the gelling temperature (determined previously) and pouring into
dispensing containers.
[0208] Determinations of whiteness and hardness were done by the
methods given earlier. All temperatures are in degrees Celsius.
1 A) Dextrin palmitate compared with Dextrin palmitate + Silicone
wax combinations Ingredients Ex. 1 (% by weight) comp. Ex. 2 Ex. 3
Ex. 4 Ex. 5 Ex. 6 Dextrin 10 5 5 5 5 5 palmitate (1) Silicone wax
-- 5 -- -- -- -- SF 1632 (3) Silicone wax -- -- 5 -- -- -- DC
X2-2493 (4) Silicone wax GE -- -- -- 5 -- -- 1205-04-261 (5)
Silicone wax -- -- -- -- 5 -- Abilwax 9810 (6) Silicone wax -- --
-- -- -- 5 AMS-C30 (7) Cyclomethi- 50.8 50.8 50.8 50.8 50.8 50.8
cone (8) C12-15 Alkyl 12.7 12.7 12.7 12.7 12.7 12.7 benzoate (9)
AZAG 7167 (10) 26.5 26.5 26.5 26.5 26.5 26.5 Characterisation
hardness (N/mm.sup.2) 0.0262 0.0077 0.0082 0.0066 0.0067 Whiteness
13 13 15 12 17 17 measurement (1 h) Whiteness 11 9 17 13 14 34
measurement (24 h)
[0209] The compositions of Examples 2 to 7 were observed to break
down when applied to skin after extrusion from a dispensing
container; this extrudate could be rubbed into skin easily.
[0210] The composition of comparative Example 1 was harder. It did
not break down as readily and was harder to rub into skin.
2 B) Dextrin palmitate + Silicone wax in different oil combinations
Ingredients (% by weight) Ex 7 Ex 8 Ex 9 Ex 10 Dextrin palmitate
(1) 5 5 5 8 Silicone wax SF 1642 (2) 5 5 5 2 Cyclomethicone (8)
50.8 50.8 50.8 50.8 C.sub.12-15 Alkyl benzoate (9) 12.7 -- -- 12.7
Isopropyl palmitate (11) -- 12.7 -- -- Isostearyl alcohol (12) --
-- 12.7 -- AZAG 7167 (10) 26.5 26.5 26.5 26.5 Characterisation
Hardness (N/mm.sup.2) 0.0053 0.0079 0.0069 0.0171 Whiteness
measurement (1 h) 14 12 12 12 Whiteness measurement 14 10 10 10 (24
h)
[0211] Compositions of Examples 7 to 9 broke down and could be
rubbed into skin easily. The composition of Example 10 was harder,
but not as hard as that of comparative Example 1.
3 C) Dextrin palmitate + wax combinations Ingredients (% by weight)
Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Dextrin 5 5 5 5 5 5
palmitate (1) Castorwax 5 -- -- -- -- -- MP80 (13) Beeswax -- 5 --
-- -- -- K62 (14) Syncrowax -- -- 5 -- -- -- HGLC (15) Syncrowax --
-- -- 5 -- -- HRC (16) Vinyl acetate -- -- -- -- 5 -- copolymer
(17) Victory Amber -- -- -- -- -- 5 Wax (18) Cyclomethi- 50.8 50.8
50.8 50.8 44.5 50.8 cone (8) C12-15 Alkyl 12.7 12.7 12.7 12.7 19.0
12.7 benzoate (9) AZAG 7167 26.5 26.5 26.5 26.5 26.5 26.5 (10)
Character- isation hardness 0.0272 0.0108 0.0086 0.0087 0.0065
0.0054 (N/mm.sup.2) Whiteness 14 18 13 15 14 12 measurement (1 h)
Whiteness 15 13 14 16 10 11 measurement (24 h)
[0212] The compositions of Examples 11 to 16 once again broke down
and could be rubbed into the skin easily, even though the hardness
of the (unextruded) composition of Example 11 was about the same as
that of comparative Example 1.
4 D) Dextrin palmitate with various waxes in various liquid
mixtures Ingredients (% by weight) Ex. 17 Ex. 18 Ex. 19 Ex. 20 Ex.
21 Ex. 22 Ex. 23 Ex. 24 Dextrin palmitate (1) 5 5 5 5 5 5 5 5
Beeswax ester K62 (14) 5 -- -- 5 -- 5 -- -- Syncrowax HGLC (15) --
5 -- -- 5 -- -- -- Syncrowax HRC (16) -- -- 5 -- -- -- 5 --
Polyethylene wax (19) -- -- -- -- -- -- -- 5 Cyclomethicone (8)
50.8 50.8 50.8 50.8 50.8 50.8 50.8 -- Isostearyl alcohol (12) 12.7
12.7 12.7 -- -- -- -- -- Alkyl benzoate (9) -- -- -- -- -- -- --
63.5 PPG-butyl ether (20) -- -- -- 12.7 12.7 -- -- -- Isohexadecane
(21) -- -- -- -- -- 12.7 12.7 -- AZAG 7167 (10) 26.5 26.5 26.5 26.5
26.5 26.5 26.5 26.5 Characterisation Hardness (N/mm.sup.2) 0.0084
0.0093 0.0086 0.0143 0.0110 0.0086 0.0071 0.0186 Whiteness
measurement (1 h) 19 14 15 21 17 19 15 12 Whiteness measurement (24
h) 17 12 14 19 15 19 15 11 E) Dextrin palmitate with fatty amides
Ingredients (percent by weight) Ex. 25 Ex. 26 Ex. 27 Ex. 28 Dextrin
palmitate (1) 5 4 3 3 Mackamide SMA (22) 3 -- -- -- Mackamide LMM
(23) -- 3 3 3 Cyclomethicone (8) 52.4 53.2 54 54 Octyldodecanol
(24) -- -- -- 13.5 C12-15 Alkyl benzoate (9) 13.1 13.3 13.5 -- AZAG
7167 (10) 26.5 26.5 26.5 26.5 Characterisation Hardness
(N/mm.sup.2) 0.0145 0.0507 0.0093 0.0147 Whiteness measurement (1
h) 19 17 15 19 Whiteness measurement (24 h) 45 33 24 30 F) Dextrin
palmitate with 12-hydroxystearic acid Ingredients (% by weight) Ex.
29 Ex. 30 Ex. 31 Ex. 32 Ex. 33 Dextrin palmitate (1) 7 7 7 7 4
12-Hydroxystearic acid (25) 3 3 3 3 6 Cyclomethicone (8) 50.8 50.8
50.8 50.8 50.8 PPG-butyl ether (20) 12.7 -- -- -- -- Isohexadecane
(21) -- 12.7 -- -- -- Isostearyl alcohol (12) -- -- 12.7 -- --
C12-15 Alkyl benzoate (9) -- -- -- 12.7 12.7 AZAG 7167 (10) 26.5
26.5 26.5 26.5 26.5 Characterisation Hardness (N/mm.sup.2) 0.0194
0.0273 0.0166 0.0338 0.0581 Whiteness measurement (1 h) 17 16 13 14
18 Whiteness measurement (24 h) 42 35 13 13 27 G) Dextrin palmitate
with 12-hydroxystearic acid and wax or fatty amide Ingredients (%
by weight) Ex. 34 Ex. 35 Ex. 36 Ex. 37 Ex. 38 Ex. 39 Ex. 40 Dextrin
palmitate (1) 3 3 2 2 3 3 2 12-Hydroxystearic acid (25) 2 3 4 4 2 2
2 Silicone wax SF 1642 (2) 5 4 -- -- -- -- -- Silicone wax AMS-C30
(7) -- -- 5 -- 5 -- -- Silicone wax Abilwax 9810 (6) -- -- -- 5 --
-- -- Beeswax ester K62 (14) -- -- -- -- -- 5 -- Mackamide LMM (23)
-- -- -- -- -- -- 3 Cyclomethicone (8) 50.8 50.8 50 50 50.8 50.8
53.2 C12-15 alkyl benzoate (9) 12.7 12.7 12.5 12.5 12.7 12.7 13.3
AZAG 7167 (10) 26.5 26.5 26.5 26.5 26.5 26.5 26.5 Characterisation
Hardness (N/mm.sup.2) 0.0072 0.0090 0.0353 0.0139 0.0079 0.0073
0.0014 Whiteness measurement (1 h) 14 16 18 20 18 20 17 Whiteness
measurement (24 h) 13 18 39 22 43 43 16 H) Dextrin palmitate with
.beta.-sitosterol and oryzanol Ingredients (% by weight) Ex. 41 Ex.
42 Ex. 43 Ex. 44 Ex. 45 Dextrin palmitate (1) 4 3 7 7 7 -sitosterol
(26) 0.5 1.5 1.5 1.5 1.5 Oryzanol (27) 0.5 1.5 1.5 1.5 1.5 Silicone
wax SF 1642 (2) -- 4 -- -- -- Cyclomethicone (8) 54.8 50.8 50.8
50.8 50.8 C12-15 Alkyl benzoate (9) 13.7 12.7 -- -- -- Isostearyl
alcohol (12) -- -- 12.7 -- -- PPG-butyl ether (20) -- -- -- 12.7 --
Isohexadecane (21) -- -- -- -- 12.7 AZAG 7167 (10) 26.5 26.5 26.5
26.5 26.5 Characterisation Hardness (N/mm.sup.2) 0.0038 0.1233
0.0595 0.1539 0.1679 Whiteness measurement (1 h) 17 16 18 17 21
Whiteness measurement (24 h) 16 11 13 31 25 J) Dextrin palmitate
with GP-1 and wax Ingredients (% by weight) Ex. 46 Ex. 47 Ex. 48
Ex. 49 Ex. 50 Ex. 51 Ex. 52 Ex. 53 Dextrin palmitate (1) 4 3 3 2 2
3 3 3 GP1 (28) 1 1 1 2 1.5 1 1 1 Silicone wax SF 1642 (2) -- -- 5 6
7 -- -- -- Silicone wax AMS-C30 (7) -- -- -- -- -- 5 -- -- Silicone
wax Abilwax 9810 (6) -- -- -- -- -- -- 5 -- Beeswax ester K62 (14)
-- -- -- -- -- -- -- 5 DC345 (8) 48 55.6 51.6 44.5 44.1 51.6 51.6
51.6 Isostearyl alcohol (12) 20.6 -- -- 19.0 -- -- -- --
Octyldodecanol (24) -- 13.9 12.9 -- 18.9 12.9 12.9 12.9 AZAG 7167
(10) 26.5 26.5 26.5 26.5 26.5 26.5 26.5 26.5 Characterisation
Hardness (N/mm.sup.2) 0.0065 0.0142 0.0144 0.0264 0.0331 0.0261
0.0208 0.0143 Whiteness measurement (1 h) 17 16 18 16 14 19 17 19
Whiteness measurement (24 h) 12 14 13 12 11 12 17 24 K) Dextrin
palmitate with GP-1 and wax or fatty acid amide Ingredients (% by
weight) Ex. 54 Ex. 55 Ex. 56 Ex. 57 Ex. 58 Ex. 59 Dextrin palmitate
(1) 2 3 3 3 3 3 N-Lauroyl-glutamic acid 1 2 1 1 1 1 di-n-butylamide
(28) Syncrowax HGLC (15) 7 5 -- -- -- -- Syncrowax HRC (16) -- -- 5
-- -- -- Syncrowax ERLC (29) -- -- -- 5 -- -- Syncrowax HRSC (30)
-- -- -- -- 5 -- Mackamide LMM (23) -- -- -- -- -- 3 Cyclomethicone
(8) 44.5 44.5 51.6 51.6 51.6 53.2 Octyldodecanol (24) 19.0 19.0
12.9 12.9 12.9 13.3 AZAG 7167 (10) 26.5 26.5 26.5 26.5 26.5 26.5
Characterisation Hardness (N/mm.sup.2) 0.0155 0.1160 0.0178 0.0176
0.0081 0.0107 Whiteness measurement (1 h) 14 17 16 17 17 17
Whiteness measurement (24 h) 19 13 14 15 15 15 L) Thickening
polymer with 12-hydroxystearic acid or wax Ingredients (percent by
weight) Ex. 60 Ex. 61 Ex. 62 Ex. 63 Kristalex F85 (polymer, 30) 7
-- -- -- N-Hance AG 50 (polymer, 31) -- 3 3 -- Kraton G 1726
(polymer, 32) -- -- -- 3 12-Hydroxystearic acid (25) 3 7 -- --
Silicone wax GE 1205-04-261 (5) -- -- 7 7 Cyclomethicone (8) 50.8
38.1 38.1 12.7 C12-15 Alkyl benzoate (9) 12.7 -- -- -- Isostearyl
alcohol (12) -- 25.4 25.4 50.8 AZAG 7167 (10) 26.5 26.5 26.5 26.5
Characterisation Hardness (N/mm.sup.2) 0.0326 0.0351 0.0099 0.0421
Whiteness measurement (1 h) 13 13 11 13 Whiteness measurement (24
h) 14 11 10 13 M) Dextrin palmitate + wax + other additives
Ingredients (% by weight) Ex. 64 Ex. 65 Ex. 66 Dextrin palmitate
(1) 5 5 5 Silicone wax SF 1642 (2) 5 5 5 Cyclomethicone (8) 49.2
49.2 49.2 C12-15 Alkyl benzoate (9) 12.3 12.3 12.3 Talc (34) 2 --
-- Polyethylene beads B9 (35) -- 2 -- Polyethylene beads C9 (36) --
-- 2 AZAG 7167 (10) 26.5 26.5 26.5 Characterisation Hardness
(N/mm.sup.2) 0.0051 0.0065 0.0083 Whiteness measurement (1 h) 14 14
14 Whiteness measurement (24 h) 12 11 11
[0213] All of Examples 17 to 66 broke down and could easily be
rubbed into skin, even though some of them had a hardness, before
extrusion, which exceeded that of Example 1.
5 N) Polyethylene compared with polyethylene + Silicone wax
combinations Ingredients Ex. 67 (% by weight) (comp.) Ex. 68 Ex. 69
Ex. 70 Ex. 71 Ex. 72 Polyethylene 5 3 3 3 3 3 (19) Silicone wax --
5 -- -- 3 -- AMS-C30 (7) GP-1 (28) -- -- 1 -- -- -- 12-hydroxy- --
-- -- 3 2 -- stearic acid (25) Micro- -- -- -- -- -- 3 crystalline
wax (37) Cyclomethi- 13.7 16.2 13.9 27.0 26.2 27.0 cone (38) C12-15
Alkyl 54.8 39.3 55.6 40.5 39.3 40.5 benzoate (9) AZAG 7167 26.5
26.5 26.5 26.5 26.5 26.5 (10) Character- isation Hardness 0.0094
0.026 0.015 0.062 0.055 0.013 (N/mm.sup.2) Whiteness 9 11 14 14 12
16 measurement (1 h) Whiteness 10 9 13 11 11 13 measurement (24
h)
[0214] The compositions of Examples 68 to 72 were observed to break
down when applied to skin after extrusion from a dispensing
container; this extrudate could be rubbed into skin easily. The
composition of comparative Example 67 had a less satisfactory feel
when applied to skin. It did not break down as readily and was
harder to rub into skin.
6 P) Vinylpyrrolidone copolymer alone and compared with
combinations Ingredients Ex. 73 (% by weight) (comp.) Ex. 74 Ex. 75
Ex. 76 Ex. 77 Triacontenyl PVP 10 5 5 5 3 copolymer (39) Lauramide
MEA (23) -- 5 -- -- -- GP-1 (28) -- -- 1 1.5 1 Silicone wax -- --
-- -- 4 AMS-C30 (7) Cyclomethicone (38) 50.8 50.8 54 53.6 52.4
C12-15 Alkyl 12.7 12.7 -- -- -- benzoate (9) Octyldodecanol (24) --
-- 13.5 13.4 13.1 AZAG 7167 (10) 26.5 26.5 26.5 26.5 26.5
Characterisation Hardness (N/mm.sup.2) 0.003 0.072 0.013 0.033
0.051 Whiteness -- 18 13 12 17 measurement (1 h) Whiteness -- 17 14
12 26 measurement (24 h)
[0215] The compositions of Examples 74 to 77 were observed to break
down easily when applied to skin after extrusion from a dispensing
container; this extrudate could be rubbed into skin easily. The
composition of comparative Example 73 was too soft to use.
7 Q) Vinylpyrrolidone copolymer and wax combinations Ingredient Ex.
78 (% by weight) (comp) Ex. 79 Ex. 80 Ex. 81 Triacontenyl PVP 5 5 5
5 copolymer (39) Syncrowax ERLC (12) -- -- -- -- Silicone wax
GE-1205-04- -- 4 -- -- 261 (5) Microcrystalline wax (5) -- -- -- --
Silicone wax -- -- -- 5 AMS-C30 (7) Cyclomethicone (38) 51.6 51.6
50.8 50.8 C12-15 Alkyl benzoate (9) 12.9 12.9 12.7 12.7 AZAG 7167
(10) 26.5 26.5 26.5 26.5 Characterisation Hardness (N/mm.sup.2)
0.029 0.025 0.04 0.074 Whiteness 15 18 17 16 measurement (1 h)
Whiteness 14 17 15 16 measurement (24 h)
[0216] The compositions of these Examples 78 to 81 were also
observed to break down easily when applied to skin after extrusion
from a dispensing container; the extrudate could 5 be rubbed into
skin easily.
Comparative Examples 81 to 85
[0217] An attempt was made to prepare soft solid formulations using
polymers as sole structurant, using the general method of
preparation given above. The formulations are given in the table
below.
8 R) Comparative examples with various polymers but no other
structurants Ingredients (% by weight) Ex. 82 Ex. 83 Ex. 84 Ex. 85
Kristalex F85 10 -- -- -- (polymer, 30) N-Hance AG 50 -- 10 -- --
(polymer, 31) Kraton G 1726 -- -- -- 10 (polymer, 32) Versamid 930
-- -- 10 -- (polymer, 33) Cyclomethicone (8) 50.8 38.1 12.7 12.7
C12-15 alkyl benzoate (9) 12.7 -- -- -- Isostearyl alcohol (12) --
25.4 50.8 50.8 AZAG 7167 (10) 26.5 26.5 26.5 26.5
[0218] In these comparative examples polymers were used alone, but
found to be unsuccessful. Example 82 separated into two phases.
Examples 83 and 84 were sticky and elastic. Example 85 was very
elastic and did not rub into skin.
Comparative Examples 86 to 89
[0219] An attempt was made to prepare soft solid compositions using
a non-polymeric fibre-forming structurant without polymer. The
method of preparation was very similar to the general method used
for previous examples.
General Preparation method
[0220] All were prepared by essentially the same method as for the
polymer thickener containing systems. Details are given below.
[0221] A solution of the structurant in the organic liquid(s) was
made by mixing these materials, heating and agitating the mixture
at a temperature sufficiently high that the structurant dissolved.
The mixture was then allowed to cool to 80-85 C. before the
aluminium antiperspirant active was added. The mixture was next
allowed to cool to 5-20 C. above its gelling temperature
(determined in a preliminary experiment) and introduced into
dispensing containers for soft solids. These were then left to cool
to room temperature.
[0222] The formulations and their hardness determined by
penetrometer are given in the following table:
9 Ingredient (percentage by weight) Ex. 86 Ex. 87 Ex. 88 Ex. 89
GP-1 1 1.5 2 5 Cyclomethicone 50.8 50.4 50.0 48.0 Octyldodecanol
21.7 21.6 21.5 20.5 AZAG 7167 26.5 26.5 26.5 26.5 Characterisation
Hardness (N/mm.sup.2) 0.007 0.038 0.034 0.165
[0223] Ex. 86 was very soft mixture and showed severe oil
leakage.
[0224] Ex. 87 and 88 also leaked solvent.
[0225] Ex. 88 dispensed in the form of flakes rather than as a
cream. It did not break down very easily when applied to skin and
rub-in was difficult to achieve.
[0226] Ex. 89 was hard and dispensed in very flaky twirls. It was
again difficult to break down and rub in.
[0227] Thus, none of these comparative examples was a satisfactory
soft solid product.
[0228] Ex. 87 was probably the closest to a satisfactory
composition. Even though Example 88 had almost the same hardness by
penetrometer, it failed to disperse as a cream, and neither
Examples 87 nor Example 88 was adequately stable.
* * * * *