U.S. patent application number 09/548309 was filed with the patent office on 2001-12-27 for cosmetic compositions.
Invention is credited to Franklin, Kevin Ronald, Hopkinson, Andrew.
Application Number | 20010055574 09/548309 |
Document ID | / |
Family ID | 10851289 |
Filed Date | 2001-12-27 |
United States Patent
Application |
20010055574 |
Kind Code |
A1 |
Franklin, Kevin Ronald ; et
al. |
December 27, 2001 |
Cosmetic compositions
Abstract
A cosmetic composition is a structured emulsion of a continuous
phase containing water-immiscible liquid carrier plus a
structurant, and a disperse phase which is a solution of
antiperspirant active in a more polar, probably aqueous, solvent.
The structurant is a material which forms a network of fibers in
the continuous phase, thereby gelling it. The structurant has an
enthalpy of gelation in the carrier liquid or a test liquid with a
magnitude of at least 30 kJ/mole. This minimum enthalpy of gelation
facilitates processing at conveniently accessible temperatures and
promotes stability.
Inventors: |
Franklin, Kevin Ronald;
(Bebington, GB) ; Hopkinson, Andrew; (Bebington,
GB) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Family ID: |
10851289 |
Appl. No.: |
09/548309 |
Filed: |
April 12, 2000 |
Current U.S.
Class: |
424/65 ; 424/400;
424/401; 424/66; 424/68 |
Current CPC
Class: |
A61K 8/34 20130101; A61K
8/63 20130101; A61K 8/31 20130101; A61K 8/342 20130101; A61K 8/60
20130101; A61K 8/26 20130101; A61K 8/06 20130101; A61K 8/37
20130101; A61K 8/891 20130101; A61K 8/02 20130101; A61K 8/894
20130101; A61K 8/73 20130101; A61K 8/28 20130101; A61Q 15/00
20130101; A61K 8/042 20130101; A61K 8/585 20130101 |
Class at
Publication: |
424/65 ; 424/66;
424/68; 424/400; 424/401 |
International
Class: |
A61K 007/32; A61K
007/34; A61K 007/38; A61K 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 12, 1999 |
GB |
9908212.5 |
Claims
1. A cosmetic composition which is a structured emulsion comprising
i) a continuous phase containing water-immiscible liquid carrier
and a fiber-forming structurant present in the continuous phase,
which is effective to gel the composition upon cooling from a
temperature at which the structurant is in solution in the carrier
liquid, and ii) a disperse phase which is a solution of
antiperspirant active in water, water-soluble solvent or a mixture
of them, characterised in that the structurant has an enthalpy of
gelation in the carrier liquid with a magnitude of at least 30
kJ/mole.
2. A cosmetic composition which is a structured emulsion comprising
i) a continuous phase containing water-immiscible liquid carrier
and a fiber-forming structurant present in the continuous phase,
which is effective to gel the composition upon cooling from a
temperature at which the structurant is in solution in the carrier
liquid, and ii) a disperse phase which is a solution of
antiperspirant active in water, water-soluble solvent or a mixture
of them characterised in that the structurant is able to gel one or
more of decamethyl cyclopentasiloxane an 80:20 wt % mixture of
decamethyl cyclopentasiloxane and isostearyl alcohol isostearyl
alcohol with an enthalpy of gelation in at least one of the liquids
with a magnitude of at least 30 kJ/mole.
3. A composition according to claim 2 wherein the structurant is
able to gel an 80:20 wt % mixture of decamethyl cyclopentasiloxane
and isostearyl alcohol with an enthalpy of gelation having a
magnitude of at least 30 kJ/mole.
4. A composition according to claim 2 wherein the structurant is
able to gel an 80:20 wt % mixture of decamethyl cyclopentasiloxane
and isostearyl alcohol with an enthalpy of gelation having a
magnitude of at least 45 kJ/mole.
5. A composition according to any one of claims 1 to 4 wherein the
disperse phase contains a diol or polyol.
6. A composition according to any one of claims 1 to 5 which
contains from 0.1% to 10% by weight of a nonionic emulsifier.
7. A composition according to any one of the preceding claims which
does not contain more than 5% by weight of any fatty alcohol which
is solid at 20.degree. C.
8. A composition according to any one of the preceding claims which
does not contain more than 2% by weight of any fatty alcohol which
is solid at 20.degree. C.
9. A composition according to any one of claims 1 to 8 which does
not contain more than 8% by weight of ethanol or any monohydric
alcohol with a vapour pressure above 1.3 kPa at 22.degree. C.
10. A composition according to any one of the preceding claims
wherein the water-immiscible liquid carrier 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, hydrophobic alcohols
and hydrophobic ethers.
11. A composition according to any one of the preceding claims
wherein the water-immiscible carrier liquid contains silicone oil
in an amount which is at least 10% by weight of the
composition.
12. A composition according to any one of the preceding claims
containing from 0.1 to 12% by weight of the structurant.
13. A composition according to any one of the preceding claims
which is an antiperspirant composition comprising an antiperspirant
active dissolved in said disperse phase.
14. A composition according to claim 13 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 is a halohydrate or complex in which aluminium and zirconium
are both present.
16. A composition according to any one of claims 13 to 15 wherein
the proportion of antiperspirant active is from 5 to 40% by weight
of the composition.
17. A composition according to any one of the preceding claims in
which a firm gel such that a penetrometer needle with a cone angle
of 9 degrees 20 minutes, drops into the gel for no more than 30 mm
when allowed to drop under a total weight of 50 grams for 5
seconds.
18. A composition according to any one of the preceding claims
which is translucent or transparent.
19. A composition according to any one of the preceding claims
which has at least 1%, and preferably at least 3%, light
transmittance at 580 nm through a 1 cm thickness of the composition
at 22.degree. C.
20. A composition according to any one of claims 1 to 19,
accommodated within a dispensing container.
21. A cosmetic product comprising a composition according to any
one of claims 1 to 19 and a dispensing container which accommodates
the composition and has at least one aperture for delivery of the
contents of the container and means for urging the contents of the
container to the said aperture or apertures.
22. A product according to claim 21 wherein the composition is in
the form of a stick and the container has an open end at which an
end portion of the stick of composition is exposed for use.
23. A process for the production of a composition according to any
one of claims 1 to 19 comprising, not necessarily in any order, the
steps of incorporating a structurant into a water-immiscible liquid
carrier mixing the liquid carrier with a disperse liquid phase,
heating the liquid carrier or a mixture containing it to an
elevated temperature at which the structurant is soluble in the
water-immiscible liquid carrier, followed by cooling or permitting
the mixture to cool to a temperature at which it is thickened or
solidified.
24. A process according to claim 23 which includes a step of
pouring the mixture at elevated temperature into a dispensing
container and allowing it to cool therein so as to produce a
product according to claim 21 or claim 22.
25. 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 19.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to cosmetic compositions for
application to human skin. Significant forms of the invention are
concerned with antiperspirant compositions for application to human
skin, especially the axilla. However, the invention can also be
applied to other forms of cosmetic composition.
BACKGROUND OF THE INVENTION AND SUMMARY OF PRIOR ART
[0002] A wide variety of cosmetic compositions for application to
human skin make use of a thickened or structured liquid carrier to
deliver colour or some other active material to the surface of the
skin. A significant example of such cosmetic compositions are
antiperspirant compositions which are widely used in order to
enable their users to avoid or minimise wet patches on their skin,
especially in axillary regions.
[0003] Cosmetic compositions have been made in a variety of 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. When a portion of the stick is drawn across
the skin surface a film of the stick composition is transferred to
the skin surface. Although the stick has the appearance of a solid
article capable of retaining its own shape for a period of time,
the material usually has a structured liquid phase so that a film
of the composition is readily transferred from the stick to another
surface upon contact. Examples of cosmetic compositions which are,
or can be, marketed in a stick form are lipsticks, lip salves and
eyebrow pencils. The stick form has been used in particular for
deodorant and antiperspirant compositions where the composition
includes a deodorant active material or an antiperspirant active
material respectively.
[0004] Another possibility is that a stick is a softer solid
composition accommodated in a dispensing container which in use
extrudes the composition through one or more apertures.
[0005] Antiperspirant sticks and other cosmetic compositions can be
divided into three categories. Suspension sticks contain a
particulate material, notably a particulate antiperspirant active
material, suspended in a structured carrier liquid phase. Emulsion
sticks normally have a hydrophilic phase forming an emulsion with a
second, more hydrophobic, liquid phase. One of the phases contains
an active material. Solution sticks typically have the active
material dissolved in a structured liquid phase; this phase may be
organic solvent or may be a mixture of water and a water-miscible
organic solvent. This classification into suspension, emulsion and
solution types can be applied to both firm and soft solid
compositions.
[0006] Besides firm and soft sticks, a number of cosmetic
compositions have taken the form of liquids which are formulated to
be somewhat viscous and hence pour and flow more slowly than water.
One example is antiperspirant compositions in liquid form, such as
applied using a roll-on applicator.
[0007] There is substantial literature on the structuring or
thickening of cosmetic compositions which is frequently
accomplished using some form of thickening agent as part of the
composition.
[0008] Some compositions have a substantial viscosity, which may
even make them capable of retaining their own shape for a time,
because of transient interactions between molecules of a thickening
agent in the liquid.
[0009] This is characteristic of compositions which are thickened
with polymers. Thickening can be attributed to interactions between
polymer molecules.
[0010] It is characteristic of such thickened compositions that
their viscosity can be achieved or recovered on standing at room
temperature. If subjected to shear their viscosity reduces (hence
they are described as shear thinning) but the viscosity recovers
towards its original value if the composition is subsequently
allowed to stand at room temperature.
[0011] Compositions which have two phases, such as emulsions may
also have substantial viscosity, even to the extent of being able
to sustain their own shape.
[0012] Here too it is characteristic of the composition
that--provided the composition is stable--its viscosity will
recover spontaneously if it is reduced by subjecting the
composition to shear.
[0013] Compositions have also been given structure and an enhanced
viscosity or rigidity by the incorporation of a structurant (also
referred to as a gellant or gelling agent) which causes the liquid
to gel upon cooling from an elevated temperature.
[0014] Gel formation takes place as an exothermic event within a
temperature range referred to as the gel point or gel temperature.
Upon reheating, melting of the gel takes place as an endothermic
event within a temperature range. When the gel melts, the
structurant goes into solution in the liquid. Such gels can be
disrupted by shearing and do not recover their viscosity for a long
time, if at all unless remelted, although a small partial recovery
may be observed.
[0015] U.S. Pat. No. 4,265,878, U.S. Pat. No. 4,725,431, U.S. Pat.
No. 4,719,103 and U.S. Pat. No. 4,704,271 disclose antiperspirant
stick compositions in which a solution of antiperspirant active in
aqueous solution is dispersed in a hydrophobic continuous phase of
hydrocarbon or silicone oil. This hydrophobic continuous phase is
structured to provide a rigid stick by the incorporation of a
substantial amount of waxy material, such as stearyl alcohol or
spermaceti wax.
[0016] One material which is well known to form 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 from Caschem.
[0017] U.S. Pat. No. 5,750,096 is one of several documents which
teaches that gelation of antiperspirant suspensions 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.
[0018] WO 98/27954, WO 97/11678 and WO 98/34588 are examples of
other documents disclosing the gelation of solutions and
suspensions.
[0019] 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.
SUMMARY OF THE INVENTION
[0020] We have recognised that when a gel is formed, the solution
of the structurant in a liquid may supercool before gelling
commences, and in consequence the gel-melting temperature may be
higher than the gel-formation temperature. If gel-formation takes
place in a quiescent solution of the structurant the extent of
supercooling may be substantial. We have observed that it varies
from one structurant to another.
[0021] However, if the structurant is being used to prepare a
product where a constituent such as a disperse phase is mixed into
the hot liquid before gel formation, we have found that it is
likely to be necessary to carry out this mixing operation at a
temperature at which the structurant is fully soluble in the
liquid. If an attempt is made to mix the composition at a
temperature at which there is some supercooling, it is likely that
the mixing will induce gelation to commence.
[0022] It is a consequence of this that when preparing structured
liquid compositions containing a structurant to gel the liquid, all
constituents of the composition must be subjected to a temperature
high enough to dissolve the structuring agent.
[0023] We have now found that advantageous properties and
processing can be provided in a cosmetic composition which is a
structured emulsion, by utilising a gelling agent, in particular a
gelling agent of moderate molecular weight, which has an enthalpy
of gelation of at least 30 kilojoule per mole.
[0024] According to a first aspect of this invention there is
provided a cosmetic composition which is a structured emulsion
comprising:
[0025] i a continuous phase containing water-immiscible liquid
carrier and a fiber-forming structurant present in the continuous
phase, which is effective to gel the composition upon cooling from
a temperature at which the structurant is in solution in the
carrier liquid, and
[0026] ii a disperse phase which is a solution of antiperspirant
active in water, water-soluble solvent or a mixture of them,
characterised in that the structurant has an enthalpy of gelation
in the carrier liquid with a magnitude of at least 30 kJ/mole,
preferably at least 35 kJ/mole, and more preferably at least 45
kJ/mole, 48 kJ/mole or 50 kJ/mole.
[0027] The enthalpy of gelation can be determined by differential
scanning calorimetry (DSC).
[0028] A gelling agent giving an enthalpy of gelation in this range
of at least 30 or 35 kJ/mole upwards can give the advantage of
allowing processing without requiring the entire composition to be
subjected to high temperature. This can be valuable in preparing a
composition which is an emulsion with a hydrophilic (e.g. aqueous)
disperse phase. A further advantage resides in stability of the
resulting gel. These advantages are more apparent if the enthalpy
of gelation is higher (45 kJ per mole or more).
[0029] By contrast, if the enthalpy of gelation is low, one or both
of two disadvantages are observed. Rather high processing
temperatures may be needed and/or a gel may be formed but then
undergo unwanted progressive transformation during storage, such as
crystals appearing and growing, softening of the composition or
leakage of liquid from it.
[0030] Although the enthalpy of gelation is a property of the
structurant and carrier liquid jointly, we have found that it is
predominantly a property of the structurant. Consequently, the
measurement of enthalpy of gelation in one or several
representative liquids is valuable as technique (which can be
carried out with a small sample and a standard instrument) to
assess the suitability of a potential structurant. It may be
desirable to take a measurement in any one of several
representative liquids, since some structurants do not gel all
hydrophobic carrier liquids.
[0031] Therefore in a second aspect this invention provides a
cosmetic composition which is a structured emulsion comprising
[0032] i) a continuous phase containing water-immiscible liquid
carrier and a fiber-forming structurant present in the continuous
phase, which is effective to gel the composition upon cooling from
a temperature at which the structurant is in solution in the
carrier liquid, and
[0033] ii) a disperse phase which is a solution of antiperspirant
active in water, water-soluble solvent or a mixture of them
[0034] characterised in that the structurant is able to gel one or
more of
[0035] decamethyl cyclopentasiloxane
[0036] an 80:20 wt % mixture of decamethyl cyclopentasiloxane and
isostearyl alcohol
[0037] isostearyl alcohol
[0038] with an enthalpy of gelation in at least one of the liquids
with a magnitude of at least 30 kJ/mole, preferably at least 35
kJ/mole, more preferably at least 45, 48 or 50 kJ/mole.
[0039] A composition according to this invention may take the form
of a firm gel with apparent rigidity, or a soft solid which is able
to retain its own shape for a time (for example if it is taken out
of a mould without being subjected to shear) but which is easily
deformed by hand pressure. Preferred within this invention are
compositions which have sufficient rigidity that they can be
regarded as firm solids. The hardness of such compositions can be
measured with a penetrometer, in a manner which will be described
in greater detail below.
[0040] Certain preferred forms of this invention are concerned with
compositions which are translucent or transparent. As is already
known, translucent or transparent compositions can be obtained if
it is possible to match the refractive indices of the different
constituent phases present in the composition.
[0041] We have found that compositions within this invention which
are a novel transparent or translucent emulsion can be obtained by
formulating the composition to meet two criteria. Firstly the
disperse phase and the continuous phase (consisting of the
water-immiscible carrier liquid and the structurant contained
within that liquid)should be formulated so that their refractive
indices match. The refractive index of the continuous phase will be
close to the refractive index of the water-immiscible carrier
liquid in it. In order to achieve good light transmission through a
composition, the refractive index of the water-immiscible
continuous phase and the refractive index of the disperse phase
should match within 0.003 units preferably 0.002 units.
[0042] Secondly, the matched refractive indices of these two phases
should lie in a range which is an approximate match to the
refractive index of the structurant. The closeness of match
required will depend on the structurant which is used. The
refractive index of a structurant can be determined by making trial
compositions as explained in more detail below. Such investigation
will also show how closely the refractive index of the liquid must
be matched to the structurant.
[0043] 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.
[0044] Another aspect of the invention therefore provides a
cosmetic product comprising a dispensing container having at least
one aperture for delivery of the contents of the container, means
for urging the contents of the container to the said aperture or
apertures, and a composition of either of the previous aspects of
the invention in the container. Preferred is that a composition of
this invention is sufficiently rigid to be accommodated as a stick
product in a dispensing container having an open end at which an
end portion of the stick of composition is exposed for use.
[0045] The compositions of this invention can be produced by
processes in which the composition is produced as a mobile liquid
at an elevated temperature and allowed to cool to permit
gel-formation.
[0046] Thus, according to a further aspect of the present invention
there is provided a process for the production of a cosmetic
composition according to the first or second aspect of this
invention comprising, not necessarily in any order, the steps
of
[0047] incorporating a structurant into a water-immiscible liquid
carrier
[0048] mixing the liquid carrier with a disperse liquid phase,
[0049] heating the liquid carrier or a mixture containing it to an
elevated temperature at which the structurant is soluble in the
water-immiscible liquid carrier,
[0050] suitably followed by
[0051] introducing the mixture into a mould which preferably is a
dispensing container, and then
[0052] cooling or permitting the mixture to cool to a temperature
at which it is thickened or solidified.
[0053] In this invention it is possible and indeed preferred that
the step of mixing with a disperse phase, and any subsequent steps,
are carried out at a temperature not exceeding 90.degree. C. and
possibly not exceeding 85.degree. C.
[0054] It may be possible to keep below these temperatures
throughout the process.
[0055] According to a yet further 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 set forth earlier comprising an antiperspirant
active in solution in the disperse phase of the composition, a
water-immiscible liquid carrier and a structurant therefor.
DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS
[0056] Measurement of enthalpy of gelation can be carried out using
a small sample and standard DSC techniques.
[0057] Measurement should be carried out at a slow cooling rate and
to promote consistency in measurement, it should, if possible, be
carried out with the concentration in a standardised range or
approximating to a standard value.
[0058] We have preferred to carry out measurement at a
concentration of structurant in the liquid which is not over 8% by
weight, preferably from 3%, better 6%, up to 8% by weight. Results
at such concentrations are generally a close approximation to
results at a standardised concentration of 7.5% by weight.
[0059] For any structurant which cannot dissolve at such a
concentration, an alternative standardised concentration would be
3% by weight.
[0060] A gel may first be made by heating and cooling, and a sample
of gel sealed in a calorimeter capsule. Alternatively the
appropriate weights of liquid and structurant could be sealed in a
calorimeter capsule, heated and allowed to cool to a gel in the
capsule.
[0061] In a preferred procedure a gel is prepared containing from 7
to 7.5% by weight of structuring agent. Approximately 20 mg of the
gel (for example between 18 and 22 mg) is weighed into a
calorimeter capsule and sealed. It is then heated at 10K/minute to
a temperature at which the structuring agent is known to be fully
soluble in the liquid, held for one minute at this temperature and
then a DSC scan is taken while cooling at 2K/minute.
[0062] The scan is repeated with a capsule containing approximately
20 mg of decamethyl cyclopentadisiloxane and in accordance with
normal DSC technique, data collected with the liquid alone
(multiplied by a scaling factor if necessary) is subtracted from
the data collected with the gel, so that the gel-formation exotherm
appears as a departure from a flat baseline. The enthalpy is the
area between the peak and the baseline.
[0063] We have found it appropriate to carry out measurements, both
on the gel and on the liquid alone, over a broad range of
temperatures, such as from -50.degree. C. to +150.degree. C. for
the sake of accuracy in subtracting one measurement from the
other.
[0064] For calculation it is assumed that the exotherm (heat given
out during gel formation) comes from the whole quantity of
structuring agent present.
[0065] Structurant
[0066] 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 by formation of a network of
fibers or strands which extends throughout the liquid, thereby
gelling the liquid. Such materials are generally non-polymeric,
being monomers or dimers with molecular weight below 10,000 rather
than polymers with more than 8 repeat units or with molecular
weight above 10,000.
[0067] Materials with this property 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.
[0068] It is characteristic of such structurants that
[0069] they are able to gel the organic liquid in the absence of
any disperse phase
[0070] the structured liquids are obtainable by cooling from an
elevated temperature at which the structurant is in solution in the
liquid--this solution being mobile and pourable
[0071] the structured liquid becomes more mobile if subjected to
shear or stress
[0072] the structure does not spontaneously recover within 24 hours
if the sheared liquid is left to stand at room temperature even
though a small partial recovery may be observed
[0073] 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 room temperature.
[0074] It appears that such structurants operate by interactions
which are permanent unless disrupted by shear or heating. Such
structurants operate by forming a network of strands or fibers
extending throughout the gelled liquid. In some cases these fibers
can be observed by electron microscopy, although in other cases the
observation of the fibers which are believed to be present is
prevented by practical difficulties in preparing a suitable
specimen. When observed, the fibers in a gel are generally thin
(diameter less than 0.5.mu., often less than 0.2.mu.) and appear to
have numerous branches or interconnections.
[0075] From our observations made using differential scanning
calorimetry we believe that fibrous networks consist of crystalline
material. The crystalline fibers may or may not be the same
polymorph as macroscopic crystals obtained by conventional
crystallization from a solvent.
[0076] A novel 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 11 carbon atoms. Preferably the cellobiose is fully
esterified, or nearly so, and is in the .alpha.-anomeric form.
[0077] The structure of such a compound in its a-anomeric form is:
1
[0078] 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 10
carbon atoms and are thus octanoyl, nonanoyl, decanoyl or
undecanoyl.
[0079] 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 the mean acyl chain length m has a value in a
range from 7 to 10 or 11. Commercially available feedstocks for
these acyl groups are likely to include a small percentage of acyl
groups which differ from the majority and may have a branched
rather than linear chain. Thus it is likely that more than 90% but
less than 100% of the acyl groups will meet the desired criterion
of chain lengths in a range from m-1 to m+1 carbon atoms.
[0080] 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.
[0081] 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.
[0082] For this invention the structurant may be an esterified
saccharide as discussed above but selected so that it also
satisfies the criterion of an enthalpy of gelation of at least 30,
preferably at least 45, kilojoule per mole.
[0083] Carrier Liquid
[0084] The water-immiscible carrier liquid in the continuous phase
comprises one or a mixture of materials which are relatively
hydrophobic so as to be immiscible in water. Some hydrophilic
liquid may be included in the carrier, provided the overall carrier
liquid mixture is immiscible with water. It will generally be
desired that this carrier is liquid (in the absence of structurant)
at temperatures of 15.degree. 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 hydrophobic carrier liquid
should consist of materials with a vapour pressure not over this
value of 4 kPa at 25.degree. C.
[0085] It is preferred that the hydrophobic carrier material
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 up to 2 kPa at 25.degree. C.
[0086] It is desirable to include volatile silicone because it
gives a "drier" feel to the applied film after the composition is
applied to skin.
[0087] Volatile polyorganosiloxanes can be linear or cyclic or
mixtures thereof. Preferred cyclic siloxanes include
polydimethsiloxanes 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.
[0088] The hydrophobic carrier 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 and Dow Corning
200 series.
[0089] The water-immiscible liquid carrier 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 lies in a range from 20%
possibly from 30 or 40% up to 100% of the weight of the
water-immiscible carrier liquid. 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.
[0090] 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.
[0091] Other hydrophobic carriers are liquid aliphatic or aromatic
esters.
[0092] 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.
[0093] 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.
[0094] Further instances of suitable hydrophobic carriers comprise
liquid aliphatic ethers derived from at least one fatty alcohol,
such as myristyl ether derivatives e.g. PPG-3 myristyl ether or
lower alkyl ethers of polyglycols such as PPG-14 butyl ether.
[0095] Aliphatic alcohols which are solid at 20.degree. C., such as
stearyl alcohol are preferably absent or 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.
[0096] 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.
[0097] Very polar materials are preferably excluded or present in
only small quantity in the water-immiscible carrier liquid.
Preferably therefore, this liquid or mixture of liquids contains
not more than 10% of its own weight, better not more than 5%, of
any constituent which is a water-miscible compound.
[0098] Silicon-free liquids can constitute from 0-100% of the
water-immiscible liquid carrier, 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
10 or 15% up to 50 or 60% by weight of the carrier liquid.
[0099] If any oxygen-containing silicon-free organic liquids are
included in the hydrophobic carrier liquid, the amount of them is
likely to be not over 70% by weight of the carrier liquid. Smaller
amounts, ranging up to 20, 30 or 35% by weight are likely.
[0100] The carrier liquid must be compatible with the structurant.
If the structurant is too soluble or conversely is very insoluble
in the carrier liquid it may fail to form a gel and the carrier
liquid should be modified to alter its polarity.
[0101] Liquid Disperse Phase
[0102] A composition of this invention is an emulsion which
contains a polar disperse phase. The disperse phase may be a
solution of an active ingredient.
[0103] The hydrophilic disperse phase in an emulsion normally
comprises water as solvent and can comprise one or more water
soluble or water miscible liquids in addition to or replacement for
water. The proportion of water in an emulsion according to the
present invention is often selected in the range of up to 60%, and
particularly from 10% up to 40% or 50% of the whole
formulation.
[0104] One class of water soluble or water-miscible liquids
comprises short chain monohydric alcohols, e.g. C.sub.1 to C.sub.4
and especially ethanol or isopropanol, which can impart a
deodorising capability to the formulation. A further class of
hydrophilic liquids comprises diols or polyols preferably having a
melting point of below 40.degree. C., or which are water miscible.
Examples of water-soluble or water-miscible liquids with at least
one free hydroxy group include ethylene glycol, 1,2-propylene
glycol, 1,3-butylene glycol, hexylene glycol, diethylene glycol,
dipropylene glycol, 2-ethoxyethanol, diethylene glycol
monomethylether, triethyleneglycol monomethylether and sorbitol.
Especially preferred are propylene glycol and glycerol.
[0105] In an emulsion the disperse phase is likely to constitute
from 5 to 80 or 85% of the weight of the composition preferably
from 5 to 50 or 65% more preferably from 25 or 35% up to 50 or 65%,
while the continuous phase with the structurant therein provides
the balance from 15 or 35% up to 95% of the weight of the
composition. Compositions with a high proportion of disperse phase
i.e. from 65 to 85% disperse phase may be advantageous because the
large proportion of disperse phase can make a contribution to
hardness.
[0106] An emulsion composition will generally include one or more
emulsifying surfactants which may be anionic, cationic,
zwitterionic and/or nonionic surfactants. The proportion of
emulsifier in the composition is often selected in the range up to
10% by weight and in many instances from 0.1 or 0.25 up to 5% by
weight of the composition. Most preferred is an amount from 0.1 or
0.25 up to 3% by weight. Nonionic emulsifiers are frequently
classified by HLB value. It is desirable to use an emulsifier or a
mixture of emulsifiers with an overall HLB value in a range from 2
to 10 preferably from 3 to 8.
[0107] It may be convenient to use a combination of two or more
emulsifiers which have different HLB values above and below the
desired value. By employing the two emulsifiers together in
appropriate ratio, it is readily feasible to attain a weighted
average HLB value that promotes the formation of an emulsion.
[0108] Many suitable emulsifiers of high HLB are nonionic ester or
ether emulsifiers comprising a polyoxyalkylene moiety, especially a
polyoxyethylene moiety, often containing from about 2 to 80, and
especially 5 to 60 oxyethylene units, and/or contain a polyhydroxy
compound such as glycerol or sorbitol or other alditol as
hydrophilic moiety. The hydrophilic moiety can contain
polyoxypropylene. The emulsifiers additionally contain a
hydrophobic alkyl, alkenyl or aralkyl moiety, normally containing
from about 8 to 50 carbons and particularly from 10 to 30 carbons.
The hydrophobic moiety can be either linear or branched and is
often saturated, though it can be unsaturated, and is optionally
fluorinated. The hydrophobic moiety can comprise a mixture of chain
lengths, for example those deriving from tallow, lard, palm oil,
sunflower seed oil or soya bean oil. Such nonionic surfactants can
also be derived from a polyhydroxy compound such as glycerol or
sorbitol or other alditols. Examples of emulsifiers include
ceteareth-10 to -25, ceteth-10-25, steareth-10-25 (i.e. C16 to C18
alcohols ethoxylated with 10 to 25 ethylene oxide residues) and
PEG-15-25 stearate or distearate. Other suitable examples include
C.sub.10-C.sub.20 fatty acid mono, di or tri-glycerides. Further
examples include C.sub.18-C.sub.22 fatty alcohol ethers of
polyethylene oxides (8 to 12 EO).
[0109] Examples of emulsifiers, which typically have a low HLB
value, often a value from 2 to 6 are fatty acid mono or possibly
diesters of polyhydric alcohols such as glycerol, sorbitol,
erythritol or trimethylolpropane. The fatty acyl moiety is often
from C.sub.14 to C.sub.22 and is saturated in many instances,
including cetyl, stearyl, arachidyl and behenyl. Examples include
monoglycerides of palmitic or stearic acid, sorbitol mono or
diesters of myristic, palmitic or stearic acid, and
trimethylolpropane monoesters of stearic acid.
[0110] A particularly desirable class of emulsifiers comprises
dimethicone copolymers, namely polyoxyalkylene modified
dimethylpolysiloxanes. The polyoxyalkylene group is often a
polyoxyethylene (POE) or polyoxypropylene (POP) or a copolymer of
POE and POP. The copolymers often terminate in C.sub.1 to C.sub.12
alkyl groups.
[0111] Suitable emulsifiers and co-emulsifiers are widely available
under many trade names and designations including Abil.TM.,
Arlacel.TM., Brij.TM., Cremophor.TM., Dehydrol.TM., Dehymuls.TM.,
Emerest.TM., Lameform.TM., Pluronic.TM., Prisorine.TM., Quest
PGPR.TM., Span.TM., Tween.TM., SF1228, DC3225C and Q2-5200.
[0112] Antiperspirant Actives
[0113] 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 whole
composition.
[0114] 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.
[0115] 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. Some activated salts do not
retain their enhanced activity in the presence of water but are
useful in substantially anhydrous formulations, i.e. formulations
which do not contain a distinct aqueous phase.
[0116] 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 2 n-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.
[0117] 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.
[0118] 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-.beta.-phenylalanine, dl-valine,
dl-methionine and .beta.-alanine, and preferably glycine which has
the formula CH.sub.2(NH.sub.2)COOH.
[0119] 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.
[0120] Other actives which may be utilised include astringent
titanium salts, for example those described in GB 2299506A.
[0121] The antiperspirant active will be dissolved in the disperse
phase. In this case, the antiperspirant active will often provide
from 3 to 60% by weight of the aqueous disperse phase, particularly
from 10% or 20% up to 55% or 60% of that phase. The weight of
antiperspirant active does not include any water of hydration which
may be present in the solid active before it is dissolved.
[0122] Optional Ingredients
[0123] 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 deodorant
effective concentrations of antiperspirant metal salts,
deoperfumes, and/or microbicides, including particularly
bactericides, such as chlorinated aromatics, including biguanide
derivatives, of which materials known as Irgasan DP300.TM.,
(Triclosan), Tricloban.TM., and Chlorhexidine warrant specific
mention. A yet another class comprises biguanide salts such as
available under the trade mark Cosmosil.TM..
[0124] 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.
[0125] A further optional constituent of the formulation comprises
one or more secondary structurants which can be employed in
addition to the esterified saccharide which is the primary
structurant. The amount of such secondary structurants in the
formulation is often zero, and usually not more than 15% of the
formulation. It is normally not greater than the amount of the
primary structurant.
[0126] The secondary structurants employable herein can be
non-polymeric or polymeric. Solid linear fatty alcohol and/or a wax
may be included but are not preferred. Non-polymeric secondary
structurants, perhaps gelling agents of lower gel formation
enthalpy, can be included. Gellants can comprise dibenzylidene
alditols, e.g. dibenzylidene sorbitol. Further suitable gellants
can comprise lanosterol, selected N-acyl amino acid derivatives,
including ester and amide derivatives, such as N-lauroyl glutamic
acid dibutylamide, which gellants can be contemplated in
conjunction with 12-hydroxy stearic acid or an ester or amide
derivative thereof. Still further gellants include amide
derivatives of di or tribasic carboxylic acids, such as alkyl N,N'
dialkylsuccinamides, e.g. dodecyl N,N'-dibutylsuccinamide.
[0127] Polymeric structurants which can be employed can comprise
organo polysiloxane elastomers such as reaction products of a vinyl
terminated polysiloxane and a cross linking agent or alkyl or alkyl
polyoxyalkylene-terminated poly (methyl substituted) or poly
(phenyl substituted) siloxanes. A number of polyamides have also
been disclosed as structurants for hydrophobic liquids. Polymers
containing both siloxane and hydrogen bonding groups, which might
be used as secondary structurants, have been disclosed in WO
97/36572 and WO 99/06473. If an aqueous disperse phase is present,
Polyacrylamides, polyacrylates or polyalkylene oxides may be used
to structure or thicken this aqueous phase.
[0128] The compositions herein can incorporate one or more cosmetic
adjuncts conventionally contemplatable for antiperspirant solids or
soft solids. Such cosmetic adjuncts can include skin feel
improvers, such as talc or finely divided polyethylene, for example
in an amount of up to about 10%; skin benefit agents such as
allantoin or lipids, for example in an amount of up to 5%; colours;
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.
[0129] Translucent/Transparent Compositions
[0130] It is possible to construct the formulation of an emulsion
such that the emulsion is translucent or transparent. In order to
do this the refractive indices of the water-immiscible continuous
phase and the polar or aqueous disperse phase must be matched to
each other and the value of refractive index at which they are
matched must also approximately match the refractive index of the
structurant.
[0131] The refractive index of a fibrous network of a structurant
can be determined by using that structurant to gel a number of oils
or oil mixtures of differing refractive index. When the resulting
gel is transparent, the refractive index of the oil or oil
mixture(which can be determined by conventional measurement) is a
good approximation to the refractive index of the structurant. The
oils or mixtures or oils should be chosen from these which are
gelled well by the structurant to avoid interfering effects. When
the gel is not transparent, but is translucent, it will indicate a
refractive index which is not precisely matched to the refractive
index of the structurant, and thus indicate an amount of mismatch
which can be tolerated without loss of translucency. It is likely
that the matched refractive indices of the liquid phases will be
not over 0.07 units below and not over 0.04 units above the
refractive index of the structurant.
[0132] Using this method we have determined the refractive index of
a preferred structurant, namely cellobiose octa-nonanoate, to fall
in a range between 1.45 and 1.50, being approximately 1.48 at
22.degree. C. With this structurant we have found that the value at
which the refractive indices of the continuous and disperse phases
are matched can be somewhat below the refractive index of the
structurant, down to a value of 1.42 or even down as far as 1.41 or
1.40. A value slightly above 1.48 would be useable also, but is
inconvenient to achieve.
[0133] For the continuous phase, silicon-free water-immiscible
liquid oils generally have refractive indices in a range from 1.43
to 1.49 at 22.degree. C. and can be used alone or mixed together to
give a silicon-free carrier liquid with refractive index in this
range. Volatile silicone oils generally have a refractive index
slightly below 1.40 at 22.degree. C., but carrier liquid mixtures
with refractive indices in the range from 1.41 to 1.46 can be
obtained by mixing volatile silicone with other oils. Non-volatile
silicone oils generally have refractive indices in a range from
1.45 to 1.48 at 22.degree. C. and so can be included when
desired.
[0134] The RI of the continuous phase will be very close to the RI
of the carrier liquid (usually a carrier liquid mixture) which is
its principal component.
[0135] For the disperse phase, a solution of an antiperspirant
active salt in water alone will generally display a refractive
index below 1.425. The refractive index can be raised by
incorporating a diol or polyol into the aqueous solution. It is
believed to be novel to match the refractive index of a polar
disperse phase to that of a structurant network within a continuous
phase. Moreover, it can be achieved without using so much diol or
polyol as will make the composition excessively sticky.
[0136] For the regular production of compositions with optimum
transparency it may prove desirable to monitor the refractive
indices of the raw materials to detect any batch to batch
variation. If necessary the composition of a liquid phase can be
adjusted by variation of the quantity of a constituent
material.
[0137] Mechanical Properties and Product Packages
[0138] The compositions of this invention are structured liquids
and may be firm or soft in appearance. Even a soft solid has an
ability to sustain its own shape, for instance if it is removed
from a mould without being subjected to shear it will retain its
shape for at least 30 seconds, usually longer.
[0139] 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. Conventional
containers take the form of a barrel of oval cross section with the
delivery aperture(s) at one end of the barrel.
[0140] A composition of this invention may be sufficiently rigid
that it is not apparently deformable by hand pressure and is
suitable for use as a stick product in which a quantity of the
composition in the form of a stick is accommodated within a
container barrel having an open end at which an end portion of the
stick of composition is exposed for use. The opposite end of the
barrel is closed.
[0141] Generally the container will include a cap for its open end
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 stick of composition is accommodated in the
barrel between the piston and the open end of the barrel. The
piston is used to urge the stick 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
stick 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.
[0142] If a composition of this invention is softer, but still
capable of sustaining its own shape it will be more suited for
dispensing from a barrel with a closure instead of an open end,
where the closure has 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.
[0143] 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.
[0144] Measurement of Properties
[0145] i) Penetrometer
[0146] The hardness and rigidity of a composition which is a firm
solid can be determined by penetrometry. If the composition is a
softer solid, this will be observed as a substantial lack of any
resistance to the penetrometer probe.
[0147] A suitable procedure is to utilises a lab plant PNT
penetrometer equipped with a Seta wax needle (weight 2.5 grams)
which has a cone angle at the point of the needle specified to be
9.degree.10'.+-.15'. A sample of the composition with a flat upper
surface is used. The needle is lowered onto the surface of the
composition and then a penetration hardness measurement is
conducted by allowing the needle with its holder to drop under a
total weight, (i.e. the combined weight of needle and holder) of 50
grams for a period of five seconds after which the depth of
penetration is noted.
[0148] Desirably the test is carried out at a number of points on
each sample and the results are averaged. Utilising a test of this
nature, an appropriate hardness for use in an open-ended dispensing
container is a penetration of less than 30 mm in this test, for
example in a range from 2 to 30 mm. Preferably the penetration is
in a range from 5 mm to 20 mm.
[0149] In a specific protocol for this test measurements on a stick
were performed in the stick barrel. The stick was wound up to
project from the open end of the barrel, and then cut off to leave
a flat, uniform surface. The needle was carefully lowered to the
stick surface, and then a penetration hardness measurement was
conducted. This process was carried out at six different points on
the stick surface. The hardness reading quoted is the average value
of the 6 measurements.
[0150] ii) Texture analyser
[0151] The hardness of a softer solid can be measured by using a
texture analyser. 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 peak force and the projected area of
indentation.
[0152] A specific test protocol used a Stable Micro systems TA.XT2i
Texture Analyser. 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 software was used to generate the
subsequent motion profile used in the test method. This profile
initially indented the sphere into the sample at an indentation
speed of 0.05 mm/s until a designated force was reached, which was
chosen such that the distance of penetration into the sample was
less than the radius of the sphere. At this load 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.
[0153] Suitable samples for measurement were either contained in
stick barrels, which had a screw mechanism, or in 15 ml glass jars.
For the barrel samples, the stick was wound up until it protruded
above the edges of the barrel and then a knife was used to skim the
top of the barrel in such a way as to leave a flat uniform surface.
The stick was then pushed back into the barrel as far as possible
to minimise any mechanical interference resulting from the
compliance of the screw mechanism in the pack. Two indents were
generally made either side of the screw. The samples in the 15 ml
jars needed no surface preparation but only had enough surface area
for a single indentation test to be performed.
[0154] The data associated with each test were manipulated using
standard spreadsheet software and used to calculate the hardness,
H, using the following equation: 1 H [ N / mm 2 ] = F max [ N ] A p
[ mm 2 ]
[0155] where F.sub.max is the peak load and A.sub.p is the
projected area of the indentation remaining on unloading. This area
can be calculated geometrically from the plastic indentation depth.
This is slightly less than the total penetration depth measured
under load because of elastic deformation of the sample. The
plastic indentation depth is calculated from a graph of the
unloading-force-versus-total-penetration-depth. The initial slope
of this unloading data depends on the initial elastic recovery of
the sample. The plastic indentation depth is estimated from an
intercept between the zero force axis and a straight line drawn at
a tangent to the initial part of the unloading slope.
[0156] Similar hardness measurements were also done using a desktop
Instron Universal Testing Machine (Model 5566) fitted with a 10 N
load cell, and the data analysis performed in the same way.
[0157] iii) Deposition and whiteness of deposit
[0158] Another test of the properties of a composition is the
amount of the composition which is delivered onto a surface when
the composition is drawn across that surface (representing the
application of a stick product to human skin). To carry out this
test of deposition, a sample of the composition with standardised
shape and size is fitted to apparatus which draws the sample across
a test surface under standardised conditions. The amount
transferred to the surface is determined as an increase in the
weight of the substrate to which it is applied. If desired the
colour, opacity or clarity of the deposit may subsequently be
determined.
[0159] A specific procedure for such tests used apparatus to apply
a deposit from a stick onto a substrate under standardised
conditions and then measures the mean level of white deposits using
image analysis.
[0160] The substrates used were
[0161] a: 12.times.28 cm strip of grey abrasive paper (3M.TM. P800
WetorDry.TM. Carborundum paper)
[0162] b: 12.times.28 cm strip of black Worsted wool fabric.
[0163] The substrates were weighed before use. The sticks were
previously unused and with domed top surface unaltered.
[0164] The apparatus comprised a flat base to which a flat
substrate was attached by a clip at each end. A pillar having a
mounting to receive a standard size stick barrel was mounted on an
arm that was moveable horizontally across the substrate by means of
a pneumatic piston.
[0165] Each stick was kept at ambient laboratory temperature
overnight before the measurement was made. The stick was advanced
to project a measured amount from the barrel. The barrel was then
placed in the apparatus and a spring was positioned to biassed the
stick against the substrate with a standardised force. The
apparatus was operated to pass the stick laterally across the
substrate eight times. The substrate was carefully removed from the
rig and reweighed.
[0166] Whiteness of Deposit
[0167] The deposits from the previous test were assessed for their
whiteness after an interval of 24 hours approximately.
[0168] This was done using a Sony XC77 monochrome video camera with
a Cosmicar 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 grey card, after the fluorescent tubes had been turned on
for long enough to give a steady light output. A cloth or
Carborundum paper with a deposit thereon from the previous test 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 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.
[0169] It has been found desirable to carry out deposition of a
standard stick composition, and determine the whiteness of the
deposit, as a control.
[0170] iv) Light transmission
[0171] The translucency of a composition may be measured by placing
a sample of standardised thickness in the light path of a
spectrophotometer and measuring transmittance, as a percentage of
light transmitted in the absence of the gel.
[0172] We have carried out this test using a dual-beam
spectrophotometer. The sample of composition was poured hot into a
4.5 ml cuvette made of polymethylmethacrylate (PMMA) and allowed to
cool to an ambient temperature of 20-25.degree. C. Such a cuvette
gives a 1 cm thickness of composition. Measurement was carried out
at 580 nm, with an identical but empty cuvette in the reference
beam of the spectrophotometer, after the sample in the cuvette had
been held for 24 hours. We have observed that a composition which
gives a transmittance of as little as 1% in this test is perceived
by eye as "translucent". If a stick is made from a composition with
3% transmittance, it is possible to see cavities made by boring
beneath the surface of the sample. By contrast, a conventional
stick structure with stearyl alcohol is so opaque that it is
impossible to see beneath its surface. A transmittance measured at
any temperature in the range from 20-25.degree. C. is usually
adequately accurate, but measurement is made at 22.degree. C. if
more precision is required. In a number of preferred examples we
have achieved a transmittance of 20% or above.
[0173] Preparation
[0174] Compositions of this invention can be produced by
conventional processes for making suspension or emulsion solids or
soft-solids. Such processes involve forming a heated mixture of the
composition at a temperature which is sufficiently elevated that
all the esterified saccharide structurant dissolves, pouring that
mixture into a mould, which may take the form of a dispensing
container, and then cooling the mixture whereupon the structurant
solidifies into a network of interconnected fibers extending
through the water-immiscible liquid phase.
[0175] In a suitable procedure for making emulsion formulations, a
solution of the esterified structurant in the water-immiscible
liquid phase is prepared at an elevated temperature just as for
suspension sticks. If any emulsifier is being used, this is
conveniently mixed into this liquid phase. Separately an aqueous or
hydrophilic disperse phase is prepared by introduction of
antiperspirant active into the liquid part of that phase (if this
is necessary; antiperspirant actives can sometime be supplied in
aqueous solution which can be utilised as is). This solution of
antiperspirant active which will become the disperse phase is
preferably heated to a temperature similar to that of the
continuous phase with structurant therein, but without exceeding
the boiling point of the solution, and then mixed with the
continuous phase. Alternatively, the solution is introduced at a
rate which maintains the temperature of the mixture. If necessary a
pressurised apparatus could be used to allow a higher temperature
to be reached, but with the structurant materials of this invention
this is usually unnecessary. After the two phases are mixed, the
resulting mixture is filled into dispensing containers, typically
at a temperature 5 to 30.degree. C. above the setting temperature
of the composition, and allowed to cool.
[0176] 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.
EXAMPLES
[0177] The examples below were prepared using a number of materials
set out with their proprietary names in the following list. All
temperature are in degrees Celsius. Refractive indices were
measured at 25.degree. C.
[0178] 1) octamethyl cyclotetrasiloxane (Volatile cyclic silicone
also known as a cyclomethicone; DC 245 from Dow Corning)
[0179] 2) decamethyl cyclopentasiloxane (Volatile cyclic silicone
also known as a cyclomethicone; DC 345 from Dow Corning)
[0180] 3 & 4) Non-volatile silicone fluids DC 556 and DC 710
(Dow Corning)
[0181] 5) Polydecene (Silkflo 364NF from Albemarle)
[0182] 6) Isostearyl Alcohol (abbreviated to ISA--Prisorine 3515
from Unichema)
[0183] 7) C12-15 alkyl benzoate (Finsolv TN from Fintex)
[0184] 8) Mineral Oil (Sirius M70 from Dalton)
[0185] 9) Polypropyleneglycol 14 butylether (Fluid AP from
Amercol)
[0186] 10) Isopropyl myristate (abbreviated to IPM from
Unichema)
[0187] 11) Isohexadecane (Permethyl 101A from Presperse Inc)
[0188] 12) Isoeicosane (Permethyl 102A from Presperse Inc).
[0189] 13) Cetyl dimethicone copolyol (Abil EM90 emulsifier from
Th. Goldschmidt)
[0190] 14) C20-C40 alcohols (Unilin 425 from Petrolite)
[0191] 15) 50% aqueous solution of Al/Zr pentachlorohydrate
(Zirkonal 50 from Giulini)
[0192] 16) Al/Zr Tetrachlorohydrex glycine complex 30% in propylene
glycol (WA2Z 8106 from Westwood)
[0193] 17) Al/Zr tetrachlorohydrex glycine complex (AZG 375 from
Summit)
[0194] 18) Glycerol (from Aldrich)
[0195] 19) Propylene glycol (from Fisons)
[0196] 20) N-lauryl-L-glutamic acid di-n-butylamide (GP-1 from
Ajinomoto)
[0197] 21) Bis-phenylpropyldimethicone, a non-volatile silicone
fluid (SF 1555 from G E Silicones)
[0198] 22) Polyglyceryl polyricinolate (Quest PGPR)
[0199] 23) 1-octyldodecanol (Eutanol G from Henkel/Cognis)
[0200] 24) Hydrogenated polyisobutene (Panalene-L-14E from
Amoco)
[0201] 25) Hydrogenated polyisobutene (Fancol 800 from Fanning
Corporation)
[0202] 26) Polyglyceryl-3-diisostearate (Lameform TGI from
Henkel/Cognis)
[0203] 27) Polyglyceryl-2-dipolyhydroxystearate (Dehymuls PGPH from
Henkel/Cognis)
[0204] 28) Polyalpha Olefins (Puresyn 4 from Mobil Chemical)
[0205] 29) Ceteareth 20 (Eumulgin B2 from Henkel)
Example 1
[0206] The enthalpy of gelation was measured for a number of
structuring agents in three liquids. In each case the gels are made
to contain 7 to 7.5 wt % of the structurant in the liquid.
[0207] A sample gel, weighing between 18 and 22 mg was placed in a
stainless steel calorimeter capsule, which was sealed with an
elastomeric O-ring. The capsule was placed in the DSC at room
temperature and heated at 10K/minute to 150.degree. C., held at
150.degree. C. for 60 seconds and cooled at 2K/minute to
-50.degree. C.
[0208] The procedure was repeated with DC 345 alone. The data
recorded for DC 345 was subtracted from the data for the gel, so
that the gel formation appears a departure from a flat baseline.
The gelation enthalpy was calculated as the area between the peak
and the baseline.
[0209] Values of enthalpy (in kJ/mole) were obtained as set out in
the following table
1 Liquid DC 345:ISA Isostearyl (80:20 ratio alcohol Structurant DC
345 by weight) (ISA) .alpha.-cellobiose octa- 360 octadecanoate
.alpha.-cellobiose octa- 108 dodecanoate .alpha.-cellobiose octa-
117 undecanoate .alpha.-cellobiose octa- 84.7 94.6 decanoate
.alpha.-cellobiose octa- 65 58 77 nonanoate .alpha.-cellobiose
octa- 57.8 octanoate 12-hydroxystearic 40 acid .beta.-sitosterol
and 22 Oryzanol in 1:1 mole ratio N-lauroyl glutamic 11 25 acid
di-n-butylamide (GP-1) lanosterol 27 7
Example 2 (Comparative)
[0210] Gels were prepared with lanosterol by a standard procedure
in which the ingredients of the gel were placed in a 30 ml glass
bottle together with a magnetic stirrer bar. The mixture was
stirred and heated until all the lanosterol had dissolved. The
bottle was then removed from the heat, the stirrer bar taken out
and the contents of the jar left to cool to room temperature.
[0211] The following was observed:
[0212] Lanosterol was found to dissolve at 10.0 wt % in Finsolv TN
at 83.degree. C. After cooling to room temperature for 1 hours a
hard, transparent gel was obtained. However the gel was found to be
unstable at room temperature: large crystalline lumps appeared
within hours and spread throughout the entire gel leading to is
collapse.
[0213] Lanosterol was found to dissolve at 5.0 wt % in 80:20 (wt %)
DC 345: Finsolv TN at 85.degree. C. After cooling to room
temperature for 1 hour a hard, translucent gel was obtained.
However the gel was found to be unstable at room temperature: large
crystalline lumps developed after 1 week.
Example 3 (Comparative)
[0214] Unsuccessful attempts were made to prepare compositions as
set out in the table below, using N-lauroyl glutamic acid
di-n-butylamide (GP-1) as structurant
[0215] The two compositions would have been emulsions where the
disperse phase would be a solution of antiperspirant active in
water (Zirkonal 50 is a 50% aqueous solution of antiperspirant
active).
2 3a 3b Example no Emulsion Emulsion Continuous phase GP-1 (20)
3.5% 5% DC 345 (2) 39% 43% Isostearyl alcohol (6) 11% Finsolv TN
(7) 16.5% Abil EM90 (13) 1% 1% Disperse Phase Zirkonal 50 (15) 40%
40% Continuous Phase Data Temp at which all the GP-1 122.degree. C.
119.degree. C. had dissolved Temperature at which the 116.degree.
C. 99.degree. C. continuous phase gelled
[0216] In each case the components of the continuous phase were
placed in a beaker and the mixture heated with stirring on a hot
plate until all the GP-1 structurant dissolved. The temperature at
which it dissolved is shown in the table above.
[0217] The intention was then to cool the mixture, while still
stirring gently to about 85-90.degree. C. in order to add the
components of the disperse solid or liquid phase. In all cases the
continuous phase gelled at a temperature (shown in the table) above
or very close to 100.degree. C., which was too high for safe
addition of the disperse phase in an open laboratory.
[0218] Safe preparation at this high temperature would have
required special measures such as pressurised apparatus.
Example 4
[0219] Cellobiose was esterified with nonanoic acid to yield the
fully esterified product in the form of its .alpha.-anomer
following a procedure generally as described in Takada et al,
Liquid Crystals, Volume 19, page 441 (1995).
[0220] The following materials were used:
[0221] .beta.-D-cellobiose, 20 grams, 0.058 moles
[0222] Nonanoic acid, 591.6 grams, 3.74 moles
[0223] Trifluoroacetic anhydride, 297.6 grams, 1.42 moles.
[0224] These materials were obtained from Acros Organics--Fisher
Scientific.
[0225] Into a 2 liter flange pot equipped with an overhead stirrer,
water condenser and addition inlet was placed the nonanoic acid
together with the trifluoroacetic anhydride. The resultant clear
mixture was stirred up and heated to 100.degree. C. using a
silicone oil bath and temperature probe. During heating it was
noted that the colour of the reaction mixture darkened and
developed a dark brown tinge. After allowing the mixture to stir
for one hour at 100.degree. C., the cellobiose was slowly added via
a solid powder funnel to the dark activated solution, and a dirty
brown suspension was formed which re-dissolved forming a clear
black solution within 10-20 minutes.
[0226] The reaction flask was then maintained at 100.degree. C. for
a total of 6 hours then cooled down to ambient laboratory
temperature. Next the contents of the flask were transferred into 2
liters of methanol containing 10% de-ionised water in an ice-cooled
5 liter beaker. Immediately an off-white solid precipitate came out
of solution, this was filtered off and collected. The crude solid
was recrystallised a total of 4 times from a
tetrahydrofuran/methanol solution producing a white solid
product.
[0227] The product was obtained in a quantity of 31.5 g which was a
37% yield. It had a melting point of 110.degree. C. The infra-red
spectrum showed an absorption peak at 1739 cm.sup.-1 for the ester
carbonyl group. The amount of free acid could be determined from
its absorption peak at 1705 cm.sup.-1.
[0228] The n.m.r. spectrum showed the amount of cellobiose which
was fully esterified to be 93.5% and showed the proportions of
product which were the .alpha.- and .beta.-anomers, (93.5%
.alpha.-anomer).
[0229] Other esters of cellobiose were prepared in the same way.
Samples of esterified cellobiose prepared as above were used to gel
various water-immiscible liquids and mixtures of liquids. The
procedure was as follows:
[0230] 0.5 grams esterified cellobiose and 9.5 grams of the liquid
(or other proportions to give a total of 10 grams) were weighed
directly into a 15 gram or 30 gram glass jar. A small magnetic
follower was placed in the jar which was then placed on a hot
plate. It was stirred and heated until all of the esterified
cellobiose had dissolved in the liquid. This "dissolution
temperature" was noted. The jar was then removed from the hot
plate, the stirrer was removed from the hot liquid in the jar. A
thermometer was placed in the liquid and the contents of the jar
were then left undisturbed to cool. The gelling temperature, i.e.
the temperature at which the contents gelled, was noted. The jar
was left to stand for 24 hours and then the contents of the jar
were inspected visually, pressed with a probe and classified
qualitatively according to their appearance as a soft, medium or
hard gel. The clarity or otherwise of the gel was noted. In most
instances the gel was remelted, the remelting temperature was
noted, and some of the melt was poured into a plastic
(polymethylmethacrylate) cuvette and allowed to cool back to
ambient laboratory temperature so that the gel reformed in the
cuvette. The transmittance of light through the 1 cm thickness of
gel in the cuvette was determined at a wave length of 580 nm using
an ultraviolet/visible spectrophotometer.
[0231] The following tables show the water-immiscible liquids which
were used, the percentage of esterified cellobiose structurant used
to gel the liquid, the dissolution temperature, the gelling
temperature, the visual appearance of the gel, the remelt
temperature and the percentage light transmittance (denoted as % T)
through 1 cm of the gel at 580 nm.
3 Gelling with .alpha.-cellobiose octa-octanoate("CB8" R =
COC.sub.7H.sub.15) % Diss Gel Remelt Liquid CB8 Temp Temp Temp % T
Visual appearance of gel ISA (6) 5 41 30 41 Hard & transparent
-> crystal growth 10 41 35 Hard & translucent -> crystal
growth DC 345 (2) 5 48 41 50 17 Hard & transparent/ translucent
10 53 50 Hard & opaque DC 556 (3) 5 48 30 45 49 Hard &
transparent 10 49 35 Hard & transparent Silkflo 5 53 45 51 22
Hard & transparent 364 NF (5) 10 55 50 Hard & opaque
Gelling with .alpha.-cellobiose octa-nonanoate ("CB9") % Diss Gel
Remelt Visual appearance Liquid CB9 Temp Temp Temp % T of gel ISA
(6) 5 57 25 46 78 Medium/hard & transparent DC 345 (2) 5 62 42
60 15 Hard & transparent/ translucent DC 566 (3) 5 69 29 52 81
Hard & transparent Silkflo 364NF (5) 5 71 40 55 78 Hard &
transparent Fluid AP (9) 5 82 38 55 37 Soft/medium &
transparent DC 345:Fluid AP 5 68 28 54 39 Soft/medium & 80:20
wt ratio transparent DC 710 (4) 5 82 48 62 11 Medium &
translucent DC 710:DC 345 5 74 33 60 4 Hard & translucent 60:40
wt ratio Gelling with .alpha.-cellobiose octa-decanoate ("CB10" R =
COC.sub.9H.sub.19) % Diss Gel Remelt Visual appearance Liquid CB10
Temp Temp Temp % T of gel Finsolv TN (7) 5 72 25 38 Very soft &
transparent gel ISA (6) 5 72 25 47 46 Medium & transparent 7 68
25 52 Hard & translucent 10 76 30 Medium & transparent DC
345 (2) 5 85 62 71 0.02 Hard & translucent/ opaque 7 84 65 59
Hard & opaque DC 556 (3) 3 79 46 59 Medium & transparent 5
n/d 50 52 2 Medium/hard & translucent 7 74 40 67 Hard &
translucent Fluid AP (9) 3 85 35 60 Medium & transparent 5 82
33 51 Medium & transparent 7 78 51 53 3 Medium &
translucent 10 84 45 Medium & translucent/opaque DC 345:Fluid 5
73 25 55 <0.01 Medium & AP translucent/opaque 80:20 wt ratio
7 82 36 49 Hard & opaque 10 83 41 Hard & opaque DC 710 (4)
5 100 80 80 0.15 Medium & opaque DC 710:DC 345 5 92 65 65 1
Medium & 60:40 wt ratio translucent/opaque trans Gelling with
.alpha.-cellobiose octa-dodecanoate ("CB12" R = COC.sub.11H.sub.23)
% Diss Gel Remelt Visual appearance of Liquid CB12 Temp Temp Temp %
T gel ISA(6) 5 54 30 48 12 Soft & transparent/trans- lucent DC
345 (2) 5 50 48 50 0.17 Soft & opaque DC 556 (3) 5 60 35 48 17
Medium & transparent/trans- lucent Silkflo 364 5 53 45 55 3
Medium & transparent NF (5) Fluid AP (9) 5 63 43 55 4 Soft
& transparent/ translucent DC 345:Finsolv 5 65 29 42 3 soft
& translucent TN 80:20 wt ratio DC 345:Fluid 5 63 42 50 0.25
Soft/medium & opaque AP 80:20 wt ratio DC 710 (4) 5 65 57 65 1
Medium & opaque DC 710:DC 345 5 65 48 55 39 Soft &
transparent 60:40 wt ratio Gelling with .alpha.-cellobiose
octa-octadecanoate ("CB18" R = COC.sub.17H.sub.35) % Diss Gel
Remelt Visual appearance of Liquid CB18 Temp Temp Temp % T gel
Finsolv TN 5 68 47 60 0.12 very soft & opaque (7) 7 68 47 IPM
(10) 5 68 50 59 0.01 very soft & opaque 7 72 50 very soft &
opaque ISA (6) 5 68 58 62 0.03 very soft & opaque 7 70 61 soft
& opaque DC 345 (2) 5 85 82 80 <0.01 soft & opaque 7 87
86 soft & opaque 10 85 84 medium & opaque DC 556 (3) 5 77
76 75 0.08 soft & opaque 7 83 79 soft & opaque 10 83 79
medium & opaque Silkflo 364 5 72 66 75 0.11 medium & opaque
NF (5) 7 72 68 medium & opaque 10 79 69 medium & opaque
Fluid AP 5 78 76 78 0.01 soft & opaque (9) 7 82 77 medium &
opaque 10 82 81 soft & opaque
[0232] It can be seen from the above table that the gelation
temperatures were low. The remelt temperatures were generally below
80.degree. C. and most of the compositions could be prepared
without any need to exceed 85.degree. C.
Example 5
[0233] Opaque emulsion sticks were prepared with formulations as
set out in the table below.
[0234] To prepare these sticks, the cyclomethicone was mixed with
the other organic liquids (if any) including the cetyl dimethicone
copolyol which functioned as an emulsifier (silicone surfactant)
and the mixture was heated with gentle stirring to a temperature 5
to 10.degree. C. above the temperature at which the structurant had
been found to dissolve in a preliminary test. The esterified
cellobiose was then added and allowed to dissolve.
[0235] The disperse phase (also referred to as internal phase) was
an aluminium zirconium active dissolved in water or in a mixture of
a polyol and water. This disperse phase was pre-heated to the same
temperature as the organic oils containing the esterified
cellobiose and added slowly to them over a period of one minute
while mixing with a Silverson mixer. After addition was complete
the formulation was mixed at higher speed for five minutes.
Stirring speed was then reduced for a further one minute after
which the mixture was poured into stick barrels and allowed to cool
undisturbed to ambient laboratory temperature. The sticks were
tested by penetrometer, by texture analyser and for whiteness of
deposits, in each instance by the test procedures given earlier.
All of the sticks were opaque although without the chalky white
appearance of a commercial white stick (CWS) structured with
stearyl alcohol and castor wax whose test results are given at the
right of the table.
4 Examples 5.1 5.2 5.3 CWS % by weight Cyclomethicone 18 22.25 21.7
DC 245 (1) Polydecene (5) 22.75 27.5 27.4 PPG-14 Butyl Ether (9)
4.5 5.5 5.4 Cellobiose octa-nonanoate 3.75 3.75 4.5 Cetyl
Dimethicone 1 1 1 Copolyol (13) Zirkonal 50 (15) 40 40 40 Water 10
-- -- Properties penetration depth (mm) 16.8 17.5 15.7 9.8 Hardness
by texture 0.11 0.10 0.12 -- analyser (N/mm.sup.2) Whiteness on
grey paper 19 16 16 118 24 hours after deposition Whiteness on
black wool 28 28.5 27 186 24 hours after deposition
Example 6
[0236] Sticks were prepared and tested in accordance with the
procedure given in Example 5. The sticks were tested for hardness
by texture analyser and/or by penetrometer. They were observed to
give deposits of low whiteness, but numerical data were not
recorded.
[0237] For some sticks in this example the refractive indices of
the water-immiscible continuous phase and the polar anti-perspirant
active solution were matched sufficiently to give translucent
sticks. Some values of transmittance are shown.
5 Examples 6.1 6.2 6.3 6.4 6.5 % by weight DC245 (1) 44 21.625
21.625 21.625 18 Silkflo364 (5) -- -- -- 21.625 4 Permethyl 102A
(12) -- 21.625 -- -- -- SF1555 (21) -- -- 21.625 -- 22 Abil EM90
(13) 1 -- -- -- 1 Quest PGPR (22) -- 1.75 1.75 1.75 -- Esterified
Cellobiose -C9 5 5 5 5 5 Zirkonal 50 (15) 39 40 40 40 40 Glycerol
(18) -- 8 9 8.75 10 Water 11 2 1 1.25 -- Properties Penetration
depth (mm) 9.3 12 11.3 13 Hardness by texture 0.10 0.12 0.12 0.21
0.13 analyser (N/mm.sup.2) Examples 6.6 6.7 6.8 6.9 6.10 % by
weight Cyclomethicone 7.6 6.8 36.5 1.7 1.25 DC 245 (1) isostearyl
alcohol (6) -- -- -- 23.3 -- octyldodecanol (23) -- -- -- -- 23.1
SF1555 (21) 37.43 37.7 7 -- -- Silkflo 364 (5) -- -- -- 16.8 17.65
Esterified 8.12 7.3 7.8 7 7 Cellobiose -C10 Cetyl Dimethicone 1.1 1
1 1 1 Copolyol (Abil EM90) (13) Westwood active (16) 43.54 41 42 40
40 Glycerol (18) -- 4.7 5.2 6.8 6.5 Water 2.21 1.5 0.5 3.4 3.5
Properties Matched RI of phases 1.45 1.45 1.46 1.45 1.45
penetration depth (mm) 9.1 6.9 8.7 8.8 9.1 Hardness by texture 0.37
0.03 0.08 0.04 0.19 analyser (N/mm.sup.2) Transmittance at 8 3 5 6
5 580 nm (%) Examples 6.11 6.12 6.13 6.14 % by weight DC245 (1) 12
11.32 -- -- Silkflo 364 (5) 32.5 30.68 39 41.5 Abil EM90 (13) 0.5
0.5 1 1 Esterified 5 7.5 10 7.5 Cellobiose -C10 Zirkonal 50 (15) 33
33 -- -- Westwood active (16) -- -- 48.06 48.06 Glycerol (18) 17 17
-- -- water -- -- 1.94 1.94 Properties penetration depth (mm) 19 14
7.3 9.6 Hardness by texture 0.44 0.07 0.47 0.15 analyser
(N/mm.sup.2)
Example 7
[0238] The procedure of Example 5 was repeated to prepare a number
of emulsion sticks with formulations set out in the following
tables. The continuous and disperse phases were formulated to have
refractive indices which matched closely at the value given in the
tables. These sticks were tested as before and the properties are
also given in these tables.
6 Examples 7.1 7.2 7.3 7.4 7.5 7.6 % by weight Cyclomethicone DC245
22.625 18.75 25.5 19 26 17.75 (1) Mineral Oil (8) 22.625 -- -- --
-- -- Polydecene (5) -- 22.5 15.75 22 15 22 PPG-14 Butyl Ether (9)
-- 4 4 -- -- 4.25 Isostearyl Alcohol (6) -- -- -- 4.25 4.25 --
Cellobiose octa- 3.75 3.75 3.75 3.75 3.75 5 nonanoate Cetyl
Dimethicone 1 1 1 1 1 1 Copolyol (13) Zirkonal 50 (15) 40 40 40 40
40 40 Glycerol (18) 10 10 7.5 10 7.5 10 Water -- -- 2.5 -- 2.5 --
Properties Matched refractive 1.43 1.43 1.425 1.435 1.425 1.43
index of phases penetration depth (mm) 19.3 18.5 17.3 24.7 23.6
12.4 Hardness by texture 0.11 0.12 0.08 0.07 0.06 0.17 analyser
(N/mm.sup.2) Whiteness on grey -- 15 16 18 19 16 paper 24 hours
after deposition Whiteness on black -- 24 28 25 30 26 wool 24 hours
after deposition Transmittance at -- 38% 33% 41% 35% 51% 580 nm
Examples 7.7 7.8 7.9 7.10 7.11 % by weight Cyclomethicone DC245 (1)
16.75 18 14.02 28.4 4.5 Polydecene (5) 20.75 22.75 17.72 13.1 50.75
PPG-14 Butyl Ether (9) 4 4.5 3.51 3.75 -- Cellobiose octa-nonanoate
7.5 3.75 3.75 3.75 3.75 Cetyl Dimethicone Copolyol 1 1 1 1 1 (13)
Zirkonal 50 (15) 40 -- 40 40 -- Glycerol (18) 10 4 17.5 6.25 12
Water -- 14 2.5 3.75 8 Propylene glycol (19) -- 12 -- -- -- AZG 375
(17) -- 20 -- -- 20 Properties Matched RI of phases 1.43 1.43 1.43
1.42 1.45 penetration depth (mm) 11 14.5 14.9 15.1 14.8 Hardness by
texture analyser 0.29 0.11 0.14 0.13 0.11 (N/mm.sup.2) Whiteness on
grey paper 24 17 20 18 21 16 hours after deposition Whiteness on
black wool 24 25 28 25 31 19 hours after deposition Transmittance
at 580 nm 48% 82% 65% 30% 72% Examples 7.12 7.13 7.14 7.15 7.16 %
by weight Cyclomethicone DC245 (1) 41.85 35.4 10.04 10.64 6.96
Permethyl 101A (11) 2.15 -- -- -- -- Permethyl 102A (12) -- 8.6 --
-- -- Polydecene (5) -- -- 12.7 13.45 8.8 PPG-14 Butyl Ether (9) --
-- 2.51 2.66 1.74 Cellobiose octa-nonanoate 5 5 3.75 2.25 1.5 Cetyl
Dimethicone 1 1 1 1 1 Copolyol (13) Zirkonal 50 (15) 40 40 52.71
52.71 60.24 Glycerol (18) 0.75 4.5 17.29 17.29 19.76 Water 9.25 5.5
-- -- -- Properties Matched refractive index of 1.40 1.41 1.43 1.43
phases penetration depth (mm) 13.5 13.2 12.0 16.8 Hardness by
texture analyser 0.16 0.15 0.13 0.07 (N/mm.sup.2) Whiteness on grey
paper 24 59 61 24 24 hours after deposition Whiteness on black wool
24 122 24 14.9 16.2 hours after deposition Transmittance at 580 nm
2.7% 5% 33% 73%
Example 8
[0239] The procedure of Example 5 was repeated to prepare a number
of emulsion sticks with formulations set out in the following
tables. As in Example 7, the continuous and disperse phases were
formulated to have refractive indices which matched closely at the
value given in the tables. The sticks were tested for hardness by
texture analyser and/or by penetrometer. They were observed to give
deposits of low whiteness, consistent with their good clarity, but
numerical data were not recorded.
[0240] The refractive indices of sample quantities of the
water-immiscible liquid mixture and the antiperspirant active
solutions were checked before making the sticks. If necessary their
formulations were modified very slightly to optimise the refractive
index match.
7 Examples 8.1 8.2 8.3 8.4 8.5 8.6 % by weight Permethyl 102A (12)
41.36 -- -- -- -- -- Panalene L-14E (24) -- -- 22 -- -- -- Fancol
800 (25) -- -- -- 22 22 -- Puresyn 4 (28) -- -- -- -- -- 22 DC245
(1) 2.64 11.4 22 22 22 22 SF 1555 (21) -- 34.1 -- -- -- --
Esterified cellobiose C9 5 4.9 5 5 5 5 Abil EM90 (13) 1 1 1 1 1 1
Zirkonal 50 (15) -- -- 40 40 36.6 40 Westwood active (16) 50 48.6
-- -- -- -- Glycerol (18) -- -- 9.35 7.5 13.4 8.75 Water -- -- 0.65
2.5 -- 1.25 Properties Matched RI of phases (at 1.46 1.45 1.431
1.425 1.437 1.429 25.degree. C.) penetration depth (mm) 9 11 10.5
12.1 7.9 8.8 Hardness by texture 0.11 0.11 0.13 0.12 0.11 0.10
analyser (N/mm.sup.2) Transmittance at 580 nm 68 70 40 6 70 37 (%)
Examples 8.7 8.8 8.9 8.10 8.11 % by weight DC245 (1) 22 22.25 22.25
21.625 -- DC556 (3) 22 -- -- -- -- Silkflo364 (5) -- -- -- -- 44
Permethyl 102A (12) -- 22.25 -- -- -- Panalene-L-14E (24) -- -- --
21.625 -- SF1555 (21) -- -- 22.25 -- -- Abil EM90 (13) 1 0.5 0.5 --
1 Lameform TGI (26) -- -- -- 0.875 -- Dehymuls PGPH (27) -- -- --
0.875 -- Esterified cellobiose C9 5 5 5 5 5 Zirkonal 50 (15) 40 40
40 40 50 Glycerol (18) 9 8 9 9.8 -- Water 1 2 1 0.2 -- Properties
Matched RI of phases (at 1.428 1.43 1.43 1.43 1.46 25.degree. C.)
penetration depth (mm) 9.0 11 11 10.5 9 Hardness by texture 0.10
0.09 0.16 0.13 0.13 analyser (N/mm.sup.2) Transmittance at 580 nm
40 22 33 36 24 (%) Examples 8.12 8.13 8.14 8.15 8.16 8.17 % by
weight DC245 (1) -- -- -- 22 22 18 Silkflo364 (5) 44 -- -- -- --
5.3 Permethyl 102A (12) -- 44 -- 22 -- -- Panalene-L-14E (24) -- --
44 -- -- -- SF1555 (21) -- -- -- -- 22 -- Octyldodecanol (23) -- --
-- -- -- 21.9 Abil EM90 (13) 1 1 1 1 1 1 Esterified 5 5 5 5 5 5
Cellobiose C9 Zirkonal 50 (15) 18 21.5 12 -- -- 37.8 AZG-375 (17)
-- -- -- 25 25 -- Glycerol (18) 32 28.5 38 0.6 2.5 11 Water -- --
-- 24.4 22.5 -- Properties Matched refractive index 1.45 1.45 1.46
1.43 1.43 1.43 of phases (at 25.degree. C.) penetration depth (mm)
9 9 7 9 8 -- Hardness by texture 0.13 0.15 0.20 -- 0.21 0.12
analyser (N/mm.sup.2) Transmittance at 580 nm 74 46 82 53 41 24
(%)
Example 9
[0241] The procedure of Example 5 was used to prepare a number of
emulsion sticks with formulations set out in the following table.
These sticks did not contain antiperspirant active. They would be
useful as moisturizing stick or lip salve and their compositions
could be used as the basis for other, probably opaque, cosmetic
stick products. The continuous and disperse phases were formulated
to have refractive indices which matched closely at the values
given in the table, but evaporative losses during processing
interfered with this. The sticks were tested for hardness by
texture analyser and/or by penetrometer.
8 Examples 9.1 9.2 9.3 9.4 % by weight DC245 (1) 22 22 16.72 19.36
Silkflo 364 (5) 22 -- 27.28 -- SF1555 (21) -- 22 -- 24.64 Abil EM90
(13) 1 1 1 1 Esterified Cellobiose C9 5 5 5 5 Glycerol (18) 33.5
37.5 -- Water 16.5 12.5 -- -- Propylene Glycol (19) -- -- 50 50
Properties Matched RI of phases (at 25.degree. C.) 1.42 1.43 1.43
1.43 penetration depth (mm) 9 9 -- 10 Hardness by texture analyser
0.13 0.15 0.15 -- (N/mm.sup.2)
Example 10
[0242] The procedure of Example 5 was used to prepare translucent
emulsion sticks with the formulation below in which the structurant
is .alpha.-cellobiose octa-undecanoate ("CB11"). As in Example 7,
the continuous and disperse phases were formulated to have
refractive indices which matched closely at the value given. The
sticks were tested for hardness by texture analyser and/or by
penetrometer. They were observed to give deposits of low
whiteness.
9 percent by weight Ingredients DC245 (1) 11 Silkflo 364 (5) 33
Abil EM90 (13) 1 Esterified Cellobiose C11 5 Zirkonal 50 (15) 33
Glycerol (18) 17 Properties Matched RI of phases(at 25.degree. C.)
1.44 penetration depth (mm) 16 Hardness by texture analyser
(N/mm.sup.2) 0.05 Transmittance at 580 nm (%) 6
Example 11
[0243] The procedure of Example 5 was used to prepare an opaque
emulsion stick of the following formulation, which included agents
to assist wash-off.
10 Ingredients percent by weight DC245 (1) 16.4 Silkflo 364 (5)
24.6 Abil EM90 (13) 1 Esterified cellobiose C9 5 Zirkonal 50 (15)
40 Glycerol (18) 10 Ceteareth 20 (29) 2.5 C.sub.20-40 alcohols (14)
0.5
* * * * *