U.S. patent application number 10/346677 was filed with the patent office on 2003-10-02 for cosmetic compositions.
This patent application is currently assigned to Unilever Home & Personal Care USA, Division of Conopco, Inc.. Invention is credited to Franklin, Kevin Ronald.
Application Number | 20030185866 10/346677 |
Document ID | / |
Family ID | 26246942 |
Filed Date | 2003-10-02 |
United States Patent
Application |
20030185866 |
Kind Code |
A1 |
Franklin, Kevin Ronald |
October 2, 2003 |
Cosmetic compositions
Abstract
An improved process for the preparation of cosmetic formulations
containing a cosmetic active and a continuous phase comprising a
water-immiscible liquid carrier, that are structured by a cyclo
dipeptide (CDP) having the general formula 1 in which R.sub.1
and/or R.sub.2, which may be the same or preferably different, each
represents a hydrocarbon or alkylene ester group and the other may
alternatively represent hydrogen, which employs a monohydric
alcohol having a melting point of below 30.degree. C. and a boiling
point of greater than 100.degree. C. and a cosmetic active material
optionally together with at least one water-immiscible liquid
carrier oil to assist in the dissolution of the structurant and
modify the gelling temperature of the resultant mixture.
Preferably, the CDP is dissolved in the monohydric alcohol and
optionally up to half the water-immiscible oil prior to being mixed
with the remaining ingredients of the composition.
Inventors: |
Franklin, Kevin Ronald;
(Wirral, GB) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Assignee: |
Unilever Home & Personal Care
USA, Division of Conopco, Inc.
|
Family ID: |
26246942 |
Appl. No.: |
10/346677 |
Filed: |
January 17, 2003 |
Current U.S.
Class: |
424/401 |
Current CPC
Class: |
A61K 8/26 20130101; A61K
8/342 20130101; A61K 8/494 20130101; C07D 241/08 20130101; A61Q
15/00 20130101; A61K 8/347 20130101 |
Class at
Publication: |
424/401 |
International
Class: |
A61K 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 18, 2002 |
GB |
0201164.1 |
Aug 1, 2002 |
GB |
0217840.8 |
Claims
1. A cosmetic composition comprising: (i) a cosmetic active
material (ii) a continuous phase which comprises a monohydric
alcohol having a melting point of below 30.degree. C. and a boiling
point of greater than 100.degree. C. and optionally at least one
water-immiscible liquid carrier oil (iii) a structurant for the
continuous phase which comprises a cyclodipeptide having the
general formula 1 4in which at least one of R.sub.1 and R.sub.2
which may be the same or different represents an aliphatic group
that is optionally substituted by an aromatic or cycloaliphatic
group and the other may alternatively represent hydrogen.
2. A composition according to claim 1 in which the monohydric
alcohol has a melting point of below 20.degree. C. and a boiling
point of greater than 120.degree. C.
3. A composition according to claim 2 in which the monohydric
alcohol is selected from linear or branched aliphatic alcohols or
benzyl alcohol that satisfy such melting and boiling point
criteria.
4. A composition according to claim 3 in which the monohydric
alcohol is iso-stearyl alcohol and/or benzyl alcohol.
5. A composition according to claim 1 in which the continuous phase
comprises at least 5% by weight monohydric alcohol.
6. A composition according to claim 5 in which the continuous phase
comprises from 20 to 80% monohydric alcohol.
7. A composition according to claim 1 or 6 in which one of R.sub.1
and R.sub.2 represents an aliphatic ester group of formula
--(CH.sub.2).sub.n--CO.sub.2--R.sub.3 in which n is an integer of
at least 1 and R.sub.3 represents an alkyl, cycloalkyl or aryl
group.
8. A composition according to claim 1 or 6 in which one of R.sub.1
and R.sub.2 represents a phenyl polymethylene group.
9. A composition according to claim 8 in which R.sub.1 represents
--CH.sub.2--Ph.
10. A composition according to claim 8 in which R.sub.2 represents
an aliphatic ester of formula --CH.sub.2--CO.sub.2--R.sub.3 and
R.sub.3 represents a carbocyclic or heterocyclic group.
11. A composition according to claim 10 in which R.sub.1 represents
--CH.sub.2--Ph.
12. A composition according to claim 11 in which R.sub.3 represents
a single ring, optionally bridged.
13. A composition according to claim 11 in which R.sub.3 comprises
a carbocyclic ring substituted by at least one alkyl or alkenyl
substituent.
14. A composition according to claim 13 in which the alkyl
substituent is methyl or isopropyl.
15. A composition according to claim 13 in which the ring in
R.sub.3 is a cyclohexane or benzene ring substituted by a methyl
and an isopropyl group that are para to each other.
16. A composition according to claim 13 in which R.sub.3 is
derivable from thymol, isopinocamphenol or a 3,5-dialkyl
cyclohexanol.
17. A composition according to claim 16 in which R.sub.3 is
derivable from thymol.
18. A composition according to claim 16 in which the 3,5-dialkyl
cyclohexanol is 3,5-dimethyl cyclohexanol.
19. A composition according to claim 1 in which the cyclo dipeptide
is present at a concentration of from 0.1 to 15% by weight of the
composition.
20. A composition according to claim 20 in which the cyclodipeptide
compound is present at a concentration of from 0.3 to 10% by weight
of the composition.
21. A composition according to claim 20 in which the cyclodipeptide
compound is present at a concentration of from 0.5 to 5% by weight
of the composition.
22. A composition according to claim 19 in which the cyclodipeptide
compound is present at a concentration of from 0.4 to 8% by weight
of the continuous phase.
23. A composition according to claim 1 in which the
water-immiscible oil comprises a silicone oil and/or a non-silicone
hydrophobic organic liquid selected from hydrocarbons, hydrophobic
aliphatic esters, aromatic esters and hydrophobic ethers.
24. A composition according to claim 1 wherein the water-immiscible
carrier liquid contains silicone oil in an amount which is at least
10% by weight of the composition.
25. A composition according to claim 1 which contains not more than
3% by weight of any fatty alcohol which is solid at 20.degree.
C.
26. A composition according to claim 1 in which the cyclo dipeptide
is employed in conjunction with a further structurant comprising an
N-acyl amino acid derivative.
27. A composition according to claim 26 in which the further
structurant is N-lauroyl glutamic acid dibutylamide.
28. A composition according to claim 1 in which 12-hydroxystearic
acid is employed as a further structurant.
29. A composition according to claim 1 in which a polyamide is
employed as a further structurant.
30. A composition according to claim 26, 27, 28 or 29 in which the
further structurant is employed in a weight ratio to the cyclo
dipeptide of from 1:10 to 10:1.
31. A composition according to claim 1 in which a further
structurant comprising a dibenzylidene alditol is employed.
32. A composition according to claim 31 in which dibenzilidene
sorbitol is employed at a weight ratio to the cyclodipeptide
structurant of from 1:3 to 1:10.
33. A composition according to claim 1 in which the composition
comprises a suspension of the cosmetic active in the structured
hydrophylic carrier liquid.
34. A composition according to claim 33 in which the carrier liquid
and the suspended cosmetic active have matched refractive indices
and has a light transmission of at least 1%.
35. A composition according to claim 1 wherein the composition is
an emulsion with the cosmetic active in solution in a hydrophilic,
preferably water-miscible, disperse phase.
36. A composition according to claim 35 wherein the disperse phase
contains a diol or polyol.
37. A composition according to claim 36 wherein the disperse phase
contains glycerol or 1,2-propane diol.
38. A composition according to claim 35 in which the composition
contains from 0.1% to 10% by weight of a nonionic emulsifier.
39. A composition according to claim 38 in which the emulsifier is
an alkyl dimethicone copolyol.
40. A composition according to claim 35 in which the refractive
indices of the disperse and continuous phases of the emulsion are
matched.
41. A cosmetic composition according to claim 1 in which the
cosmetic active is an antiperspirant or deodorant active.
42. A composition according to claim 41 in which 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.
43. A composition according to claim 41 in which the complex
contains both aluminium and zirconium.
44. A composition according to claim 41 which contains from 5 to
40% by weight of the antiperspirant active.
45. An cosmetic product comprising a dispensing container having an
aperture for delivery of a stick, means for urging the contents of
the container to the said aperture or apertures, and a composition
according to claim 1 accommodated within the container.
46. A product according to claim 45 wherein the composition is a
firm gel such that a penetrometer needle with a cone angle of 9
degrees 10 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.
47. A process for the production of a composition according to
claim 1 comprising the steps of: a) forming a mixture containing a
liquid carrier, a structurant dissolved therein, and a solid or a
disperse liquid phase comprising cosmetic active in particulate or
dissolved form at a temperature of at least 40.degree. C. and is
above the setting temperature of the mixture; b) introducing the
mixture into a mould which preferably is a dispensing container,
and c) cooling or permitting the mixture to cool to ambient
temperature, in which the structurant is a cyclo dipeptide that
satisfies the general formula 1: 5in which at least one of R.sub.1
and R.sub.2 which may be the same or different represents an
aliphatic group that is optionally substituted by an aromatic or
cycloaliphatic group and the other may alternatively represent
hydrogen, and the carrier comprises a monohydric alcohol having a
melting point of below 30.degree. C. and a boiling point of greater
than 100.degree. C., and optionally at least one water-immiscible
liquid carrier oil.
48. A process according to claim 47 in which the carrier comprises
at least one water-immiscible liquid carrier oil and at least 5%
monohydric alcohol.
49. A process according to claim 48 in which the carrier comprises
from 20 to 80% by weight monohydric alcohol.
50. A process according to any of claims 47 in which the
water-immiscible liquid carrier comprises a silicone oil and/or an
aromatic ester.
51. A process according to claim 47 in which the cyclo dipeptide
structurant is dissolved in the monohydric alcohol and up to half
of the water-immiscible oil prior to being mixed with the
water-immiscible oil or a residual fraction thereof.
52. A process according to claim 47 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 41.
53. A cosmetic method for preventing or reducing perspiration on
human skin comprising topically applying to the skin a composition
according to claim 1.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to cosmetic compositions for
application to human skin, to the preparation and use of such
compositions and to structurants for incorporation in such
compositions and their preparation.
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 structured liquid carrier to deliver
colour or some other active material to the surface of the skin.
Significant examples of such cosmetic compositions include
antiperspirant or deodorant compositions which are widely used in
order to enable their users to avoid or minimise wet patches on
their skin, especially in axillary regions or to control or prevent
the emission of malodours, which could otherwise arise when the
user perspires. Other examples of cosmetic compositions include lip
sticks.
[0003] Although structuring is a term that has often been employed
in respect of materials which structure a carrier liquid, various
other terms have been employed alternatively, including thickening,
solidifying and gelling.
[0004] Antiperspirant or deodorant formulations have been provided
with a range of different product forms. One of these is a
so-called "stick" which is usually a bar of an apparently firm
solid material held within a dispensing container and which retains
its structural integrity and shape whilst being applied. In that
respect they are representative of cosmetic compositions in stick
form containing other active constituents. 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 often has a structured
liquid phase so that a film of the composition is readily
transferred from the stick to another surface upon contact.
[0005] Antiperspirant sticks can be divided into three categories.
Suspension sticks contain a particulate antiperspirant active
material suspended in a structured carrier liquid phase which often
is anhydrous and/or in many instances may be water-immiscible.
Emulsion sticks normally have a hydrophilic phase, commonly
containing the antiperspirant active in solution, this phase
forming an emulsion with a second, more hydrophobic, liquid phase.
The continuous phase of the emulsion is structured. Solution sticks
typically have the antiperspirant active dissolved in a structured
liquid phase which is polar and may comprise a polar organic
solvent, which is often water-miscible, and the polar phase can
contain water.
[0006] There is substantial literature on structuring of cosmetic
compositions, for example as represented by antiperspirant or
deodorant compositions.
[0007] Conventionally, many sticks have been structured using
naturally-occurring or synthetic waxy materials, in which term we
include materials which resemble beeswax, in that they soften
progressively with increase in temperature until they are fluid,
generally by about 95.degree. C. Examples of wax-structured sticks
are described in an article in Cosmetics and Toiletries, 1990, Vol
105, P75-78, in U.S. Pat. Nos. 5,169,626 and 4,725,432 and in many
other publications, in some of which such materials are called
solidifying agents.
[0008] More specifically, it has been common practice for sticks to
be structured or solidified by incorporating fatty alcohol into the
composition, often accompanied by a smaller amount of castor wax.
Sticks which are structured with fatty alcohol tend to leave
visible white deposits on application to human skin; moreover the
deposits can also transfer onto clothing when it comes into contact
with the skin and the wearer can, for example, find white marks at
the armhole of the sleeveless garment. Fatty alcohols are often
regarded as coming within the general category of waxy materials,
but we have observed that they are a more significant source of
white deposits than various other waxy materials.
[0009] Some alternative structurants or solidifying agents to waxy
materials have been proposed. For example, the use of dibenzylidene
sorbitol (DBS) or derivatives thereof as gellant for a polar or
hydrophylic carrier liquid has been proposed in a number of
publications such as EP-A-512770, WO-92/19222, U.S. Pat. Nos.
4,954,333, 4,822,602 and 4,725,430. Cosmetic formulations
containing such gellants can suffer from a number of disadvantages,
including instability in the presence of acidic antiperspirants,
and comparatively high processing temperatures needed in the
production of sticks.
[0010] Other alternative proposed structurants include various
classes of esters or amides that are solid at ambient temperature
and are capable of solidifying a hydrophobic or water-immiscible
liquid carrier. One such class comprises ester or amide derivatives
of 12-hydroxystearic acid, as described in inter alia U.S. Pat. No.
5,750,096. Another class of such esters or amides comprises N-acyl
amino acid amides and esters, of which N-Lauroyl-L-glutamic acid
di-n-butylamide is commercially available from Ajinomoto under
their designation GP-1. They are described in U.S. Pat. No.
3,969,087. A further class which has been disclosed as gelling
agents comprises the amide derivatives of di and tribasic
carboxylic acids set forth in WO 98/27954 notably alkyl
N,N'-dialkyl succinamides. Yet other amide structurants for
water-immiscible liquid carriers are described in EP-A-1305604.
[0011] One further class of compounds that have been contemplated
as a gelator for cosmetic oils comprises cyclodipeptides. Such
compounds contain a --CO--NH-- group, and can be considered to be
cyclic derivatives of aminoacids.
[0012] Various cyclodipeptides has been described in an article by
K Hanabusa et al entitled Cyclo(dipeptide)s as low molecular-mass
Gelling Agents to harden Organic Fluids, J. Chem Soc. Commun., 1994
pp1401/2. Various other cyclo(dipeptides) satisfying formula 1
above were described in a second article by Hanabusa et al entitled
Low Molecular
[0013] Weight Gelators for Organic Fluids: Gelation using a Family
of Cyclo(dipeptide)s, in the Journal of Colloid and Interface
Science 224, 231-244 (2000). Further cyclodipeptides have been
described in Japanese Kokai 10-226615 (1998) or 13-247451 (2001) to
Polar Chemical Industries Inc. in which Hanabusa was a named
inventor. In the course of the research leading to the present
invention, cyclo-dipeptides such as various of those disclosed by
Hanabusa were investigated and a sub-class of cyclo dipeptides
exhibiting superior gelating properties was identified and
described in an as yet unpublished copending application no
GB0201164.1 filed in GB on 18 Jan. 2002.
[0014] Without being bound to any specific theory or explanation,
we believe that, upon structuring of a water-immiscible oil, a
network of fibres is formed of the cyclodipeptides that extends
throughout the liquid phase, at least increasing the viscosity of
the phase and preferably gelling that phase. Upon heating the gel
to the gel melting temperature, the strands of structurant dissolve
and the liquid phase becomes more mobile. Within the class of
compounds identified as cyclodipeptides, the capability of
individual members of that class to form a network and the
conditions in which a network forms will vary, as will the
stability of a network, once formed. However, the class shares the
properties outlined below to a greater or lesser extent.
[0015] Although cyclo dipeptides can be extremely effective
gellants for cosmetic oils, the manufacture of compositions in
which they are employed as gellants is subject to a number of
practical constraints or difficulties. First, it is often difficult
to incorporate sufficient cyclic dipeptide into the cosmetic oil to
enable it to structure or gel the oil to the extent that would be
preferred by the manufacturer. That is because the cyclic
dipeptides are relatively poorly soluble in commonly employed
cosmetic oils, such as volatile or even non-volatile silicone oils.
It would be inherently desirable to find a way of increasing the
solubility of cyclo dipeptides in the water-immiscible liquid phase
of cosmetic formulations.
[0016] A further property of cyclic dipeptides relates to the
gelling temperature of cosmetic oils containing them. As a
generalisation, they tend to gel at higher temperatures than for
example waxes or like commonly employed gellants. Furthermore, and
unsurprisingly, the gelling temperature of a solution of such a
gellant in such oils increases as its concentration in solution
increases. The net consequence of its gelation behaviour is that if
enough cyclic dipeptide is present to cause the resultant product
to have a preferred firmness at ambient temperature, the gelation
temperature of the cyclic dipeptide in the oil is undesirably high,
commonly in the region of or in excess of 100.degree. C. At such
temperatures, many cosmetic oils can evaporate or become
discoloured and if the formulation is in the form of an emulsion
stick, water evaporation renders the preparation of accurate
composition extremely difficult and at worst impossible. Moreover,
increased processing temperatures can also result in degradation or
discoloration of some cyclic dipeptides themselves. It would be
inherently desirable to find a way of lowering the gelling
temperature at which a water-immiscible oil phase occurs to a
controllable extent.
[0017] The instant inventors accordingly concluded that it would be
desirable to identify variations in processing that could
ameliorate or overcome the foregoing operational constraints,
preferably both at the same time.
SUMMARY OF THE INVENTION
[0018] Applicants have now found that the processing of cosmetic
formulations employing a cyclodipeptide as a gelling agent for a
cosmetic oil carrier can be improved by employing a class of
materials that can act as a solvent for the cyclo dipeptides and
which is miscible with the cosmetic oils.
[0019] It is an object of the present invention to provide
structured cosmetic compositions, in which a liquid carrier
material is structured using a cyclo dipeptide structurant in the
presence of a solvent for the cyclo dipeptide which is miscible
with the carrier.
[0020] Broadly, in a first aspect of the present invention, there
is provided a cosmetic composition comprising:
[0021] (i) a cosmetic active material
[0022] (ii) a continuous phase which comprises a monohydric alcohol
having a melting point of below 30.degree. C. and a boiling point
of greater than 100.degree. C. and optionally at least one
water-immiscible liquid carrier oil
[0023] (ii) a structurant for the continuous phase which comprises
a cyclodipeptide having the general formula 1 2
[0024] in which at least one of R.sub.1 and R.sub.2 which may be
the same or different represents an aliphatic group that is
optionally substituted by an aromatic or cycloaliphatic group and
the other may alternatively represent hydrogen.
[0025] Such an monohydric alcohol is miscible with commonly
employed or contemplated water-immiscible cosmetic oils and
therefore be employed to ameliorate the problems identified above,
whilst still retaining the benefits from employing such oils.
[0026] By employing a monohydric alcohol having the physical
attributes identified above as an essential component of the
continuous carrier for the cosmetic active, it is possible to
render it easier to obtain structured compositions using the
selected structurant, and can also or alternatively enable
compositions to be obtained in which the problem of undesirable
discoloration can be reduced or eliminated. The incorporation of
the selected alcohol can lower the temperature at which the desired
concentration of structurant dissolves when the carrier also
comprises a water-immiscible oil and can also increase the
concentration of the cyclic dipeptide which can dissolve in the
carrier phase, and furthermore can ameliorate or avoid the problem
of the mixture becoming immobile at an excessively high
temperature.
[0027] A solution of the structurant in the cyclo dipeptide
compound in the monohydric alcohol or its optional mixture with a
water-immiscible oil indicates herein that a separate distinct
structurant phase is no longer discernible to the human eye.
[0028] 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.
[0029] A second aspect of the invention therefore provides a
cosmetic product comprising a dispensing container having an
aperture for delivery of the contents of the container, means for
urging the contents of the container through the said aperture, and
a composition of the first aspect of the invention in the
container.
[0030] Means for urging the contents of the container to the said
aperture or apertures, for flow through them, may be moving parts
operable by the user or an orifice in the container opposite the
aperture providing digital access.
[0031] According to a third aspect of the present invention there
is provided a process for the production of a cosmetic composition
comprising the steps of:
[0032] a) forming a mixture containing a liquid carrier, a
structurant dissolved therein, and a solid or a disperse liquid
phase comprising cosmetic active in particulate or dissolved form
at a temperature of at least 40.degree. C. and is above the setting
temperature of the mixture;
[0033] b) introducing the mixture into a mould which preferably is
a dispensing container, and
[0034] c) cooling or permitting the mixture to cool to ambient
temperature, characterised in that the structurant is a cyclo
dipeptide that satisfies the general formula 1: 3
[0035] in which at least one of R.sub.1 and R.sub.2 which may be
the same or different represents an aliphatic group that is
optionally substituted by an aromatic or cycloaliphatic group and
the other may alternatively represent hydrogen,
[0036] and the carrier comprises a monohydric alcohol having a
melting point of below 30.degree. C. and a boiling point of greater
than 100.degree. C., a cosmetic active material and optionally at
least one water-immiscible liquid carrier oil,
[0037] A suspended solid may be any cosmetic active that is at
least partly insoluble in a lypophilic water-immiscible liquid
carrier in the amount incorporated therein and a disperse liquid
phase may be a solution of such an active in a hydrophilic or polar
solvent.
[0038] The cyclo dipeptide may conveniently be dissolved in the
monohydric alcohol alone or in the presence of only a fraction of
any water-immiscible cosmetic oil. Alternatively, all the cosmetic
oil can be present at the dissolution stage. The former process
variant is particularly desired.
[0039] In a fourth aspect of the present invention, the cosmetic
active comprises an antiperspirant or deodorant active. Thus,
according to the fourth aspect, there is provided a cosmetic method
for preventing or reducing perspiration or odour formation on human
skin comprising topically applying to the skin a composition
comprising a cosmetic active, a water-immiscible liquid carrier and
a structurant compound as defined above in the first aspect in
which the cosmetic active is an antiperspirant or deodorant
active.
DETAILED DESCRIPTION AND EMBODIMENTS
[0040] The present invention relates to compositions containing a
cosmetic active and a water-immiscible phase that is structured
with a cyclodipeptide, to a process for their preparation, to their
use and to products containing them. Such compositions and the
dispensing package will be described in greater detail, including
preferences for individual constituents and combinations thereof
and preferred process operations.
[0041] Structurant--Cyclo Dipeptides
[0042] The cyclo dipeptides, sometimes referred to subsequently
herein as CDPs, that can be employed in the instant invention can
comprise any cyclo dipeptide that satisfies general formula 1
above.
[0043] It will recognised that the extent to which a CDP is able to
structure a water-immiscible carrier liquid or mixture containing
it and the properties of the resultant structured material depend
upon many factors, including the CDP itself, the chemical nature of
the water-immiscible oil or mixture containing it, and the weight
ratio of DPD to the oils. For example, different CDPs have
different inherent capabilities to structure oils, often
manifesting itself in the range of oils which they can structure
and/or the long term physical stability of the resultant structured
oil and different oils have different inherent propensity to be
structured, often manifesting itself in the range of CDPs that can
structure them. An increasing ratio of CDP to carrier oil assists
in structuring the oil. Structuring herein indicates the formation
of a composition having an increased viscosity compared with a
corresponding composition free from CDP, but more desirably the
CDP/oils and proportions are chosen together such that the
composition is gelled at ambient temperature. A gelled composition
does not flow within 24 hours out of a filled container of 2 cm
diameter that is lain horizontally at 20.degree. C. It can be
assessed more quickly as having gelled by employing the test iii)
described hereinafter.
[0044] In the CDPs herein, R.sub.1 and/or R.sub.2 are desirably
linked to the cyclodipeptide nucleus through a methylene group
--CH.sub.2--. Commonly, R.sub.1 is different from R.sub.2. In many
suitable embodiments, one of R.sub.1 and R.sub.2 (the other being
H) or more preferably both R.sub.1 and R.sub.2 are selected from
aliphatic hydrocarbon groups, preferably saturated, which may be
linear or branched, optionally terminating in or substituted by an
aryl or cycloaliphatic group, and from aliphatic esters of formula
--(CH.sub.2).sub.n--CO.sub.2--R.sub.3 in which in which n is 0 or
preferably an integer of at least 1 and R.sub.3 represents an
alkyl, cycloalkyl or aryl group. The number of carbons in each of
R.sub.1 and R.sub.2 is often selected in the range of from 1 to 35
and in many instances from 1 to 20.
[0045] Examples of suitable alkyl groups for R.sub.1 and/or R.sub.2
include ethyl, isopropyl, and isobutyl groups. Others which may be
contemplated include 2-ethylbutyl, hexyl, 3-methyl-isononyl, and
dodecanyl. Examples of suitable aliphatic ester groups for R.sub.1
and/or R.sub.2 include esters in which n=0 or 1 or 2, and
particularly where n=1. In such or other ester groups, R.sub.3 can
represents an alkyl group containing at least 2 carbons,
particularly up to 20 carbons, which may be linear or branched,
such as an ethyl, isopropyl, isobutyl, 2-ethylbutyl, hexyl,
3-methyl-isononyl, dodecanyl, hexadecanyl or octadecanyl group.
[0046] In a number of preferred embodiments, R.sub.3 represents a
carbocyclic or heterocyclic group.
[0047] In such embodiments, R.sub.3 can comprise two fused rings,
but preferably comprises a single six membered ring, either
carbocyclic or heterocyclic, or a bridged ring. When R.sub.3 is
carbocyclic, it can be either saturated or unsaturated, preferably
mono- or di-unsaturated or aromatic. When R.sub.3 is heterocyclic,
it is preferably saturated.
[0048] R.sub.3 is preferably substituted by at least one alkyl
substituent, R.sub.4, either directly onto the ring or optionally
indirectly via an interposed ether or ester linkage. R.sub.4
preferably contains no more that 19 carbon atoms, such as one
having a longest chain length of up to 4 carbon atoms, and/or a
total carbon content of up to 5 carbon atoms. R.sub.4 may be linear
or branched. Preferred examples include methyl, ethyl, propyl,
isopropyl, butyl isobutyl or t-butyl or isopentyl. In a number of
very suitable cyclo dipeptides, at least two or more R.sub.4
substituents are present, both or all especially desirably being
selected from the above list of preferred examples. The R.sub.4
substituents may be the same, such as two or more methyl
substituents, or may be a combination of different substituents
such as a methyl and isopropyl substituents. When R.sub.3 is
saturated, the R.sub.4 substituents may depend from the same carbon
atom in the ring, such as two methyl groups, or from different
carbon atoms. In several highly desirable cyclic dipeptides, two
alkyl R.sub.4 substituents are meta or para to each other, for
example two methyl groups that are meta to each other or a methyl
group and an isopropyl group that are para to each other. In yet
other cyclo dipeptides, the ring may include a methylene bridge,
which preferably likewise completes a six membered ring.
[0049] When R.sub.4 is linked to the ring via an ester linkage, the
carbonyl carbon in the ester linkage is preferably directly bonded
to the ring. In various desirable cyclic dipeptides, R.sub.3
satisfies the formula --Ph--CO--O--R.sub.4 in which R.sub.4 is as
described above and particular where R.sub.4 comprises 3 to 6
carbons, such as n-butyl.
[0050] When R.sub.A is heterocyclic, the heterocyclic atom is
suitably nitrogen. Conveniently, the heterocyclic atom can be para
to the bond with the cyclo dipeptide residue. Moreover, in a number
of desirable cyclo dipeptides, the heteroatom is ortho to at least
one alkyl group R.sub.4, better in a saturated ring and especially
to up to 4 ortho R.sub.4 groups, that especially are methyl
groups.
[0051] Examples of such especially preferred R.sub.3 group include
thymol, isopinocamphenol and 3,5-dialkyl cyclohexanol such as
3,5-dimethyl cyclohexanol.
[0052] In several highly desirable embodiments, R.sub.1 represents
a benzyl group and R.sub.2 is an ester of formula
(CH.sub.2).sub.n--CO.sub.- 2--R.sub.3 especially those in which
n=1, and R.sub.3 represent a carbocylic or heterocyclic group as
described above.
[0053] Continuous Phase--Carrier Oils
[0054] Herein, the carrier oils include a monohydric alkanol oil
optionally together with at least one water-immiscible carrier
cosmetic oil.
[0055] The monohydric alkanol for employment in herein can comprise
any alkanol which has a melting point that is no higher than
30.degree. C. and a boiling point that is greater than 100.degree.
C. Preferred alkanols have a melting point that is below 25.degree.
C. and especially below 20.degree. C. Preferably, the alkanols have
a boiling point that is greater than 120.degree. C. and
particularly one that is greater than 150.degree. C. Boiling point
and melting point data for alkanols is commonly available, or can
be readily determined using standard apparatus. Without being
prescriptive, alkanols having a suitable melting point and boiling
point can be selected from intermediate chain length linear
alkanols, such as butanol through to decanol, eg octanol or
decanol; or short cycloalkanols such as cyclopentanol through to
cycloheptanol, optionally methyl substituted; intermediate or
longer chain length branched alkanols, containing for example from
5 to 24 carbons and especially at least 10 carbons, such as
secondary aliphatic alcohols, eg isolauryl alcohol isocetyl alcohol
isopalmityl alcohol and isostearyl alcohol or secondary alcohols in
which the branch contains from 2 to 10 carbons, such as octyl
dodecanol. Still other suitable alcohols can be selected from
phenyl-terminated short chain aliphatic alcohols, such a benzyl
alcohol and phenylethyl alcohol. Mixtures of such alcohols can be
employed, both within the sub-classes of alcohols and between the
sub-classes.
[0056] It is beneficial to choose monohydric alcohols that
themselves are comparatively water-immiscible or at best poorly
miscible. In practice, the monohydric alcohols above-identified by
name normally satisfy such a preference and such a property is
ascertainable from standard reference works. Any doubt can be
resolved by conducting a simple test. In such a test, preferred
alcohols are those which are incapable of forming a stable, single
phase when mixed gently with de-ionised water (ie in the absence of
any solubilising agent or hydrotrope) at 25.degree. C. in a weight
ratio of 20 parts alcohol to 80 parts water.
[0057] The continuous phase carrier liquid system commonly
comprises one or a mixture of materials which are relatively
hydrophobic so as to be immiscible in water, in addition to the
monohydric alcohol.
[0058] The weight proportion of the monohydric alcohol in the
carrier liquid is at the discretion of the user. Naturally, it will
be understood that the beneficial lowering of the gelation
temperature and/or the increase in concentration of structurant
that can be incorporated increases non-linearly with the proportion
of the monohydric alcohol in the carrier. In practice, the choice
of weight proportions takes into account many factors, such as the
extent to which a particular CDP suffers from the problems in
water-immiscible oils described in the introductory section of this
text, and/or which sensory or physical properties are more
preferred in the eventual product. The proportion of the monohydric
alcohol is normally selected in the range of from 5 to 100% of the
weight of the carrier oils. In many embodiments, its weight
proportion is at least 20%. To permit significant variation in the
sensory properties of the eventual composition, the weight
proportion of the monohydric alcohol conveniently is not more than
70% or 80% of the carrier oils.
[0059] The more the monohydric alcohol that is present, the greater
the extent to which it can enhance the solubility of the CDP and
lower the gelling temperature of the liquid carrier. In many
compositions according to the present invention, the selected
monohydric alcohol is present in a weight ratio to the CDP of at
least 1:1, particularly at least 2:1 and in many practical
embodiments is at least 4:1. Although a weight ratio to the CDP of
greater than 100:1 can be contemplated, the weight ratio is
normally up to 100:1, and in many instances is up to 70:1. In
various practical embodiments, the weight ratio to CDP is up to
20:1.
[0060] 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.
[0061] 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 to 2 kPa at 25.degree. C.
[0062] It is desirable to include volatile silicone because it
gives a "drier" feel to the applied film after the composition is
applied to skin.
[0063] Volatile polyorganosiloxanes can be linear or cyclic or
mixtures thereof. Preferred cyclic siloxanes include
polydimethylsiloxanes and particularly those containing from 3 to 9
silicon atoms and preferably not more than 7 silicon atoms and most
preferably from 4 to 6 silicon atoms, otherwise often referred to
as cyclomethicones. Preferred linear siloxanes include
polydimethylsiloxanes containing from 3 to 9 silicon atoms. The
volatile siloxanes normally by themselves exhibit viscosities of
below 10.sup.-5 m.sup.2/sec (10 centistokes), and particularly
above 10.sup.-7 m.sup.2/sec (0.1 centistokes), the linear siloxanes
normally exhibiting a viscosity of below
5.times.10.sup.-6m.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 --0--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.
[0064] 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 products available under the
trademarks Dow Corning 556 and Dow Corning 200 series. Other non
volatile silicone oils include that bearing the trademark DC704.
Incorporation of at least some non-volatile silicone oil having a
high refractive index such as of above 1.5, eg at least 10% by
weight (preferably at least 25% to 100% and particularly from 40 to
80%) of the silicone oils is often beneficial in some compositions,
because this renders it easier to match the refractive index of the
constituents of the composition and thereby easier to produce
transparent or translucent formulations.
[0065] The water-immiscible oil employed in the carrier in addition
to the monohydric alcohol may comprise from 0% to 100% by weight of
one or more liquid silicones. In some embodiments, there is
sufficient liquid silicone to provide at least 10%, better at least
15%, by weight of the whole composition. When silicone oil is used
in various embodiments, for example in emulsions, volatile silicone
preferably constitutes from 20 to 100% of the weight of the carrier
liquid. In a number of embodiments, when a non-volatile silicone
oil is present, its weight ratio to volatile silicone oil is chosen
in the range of from 5:1 to 1:50.
[0066] Silicon-free hydrophobic oils can be used instead of, or
more preferably in addition to liquid silicones. Silicon-free
hydrophobic organic oils that 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.
[0067] Other suitable hydrophobic carriers comprise liquid
aliphatic or aromatic esters. 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, di-isopropyl sebacate and di-isopropyl adipate.
[0068] 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, including in particular C.sub.12 to
C.sub.15 alkyl benzoates eg those available under the trademark
Finsolv. Other suitable aromatic esters include alkyl naphthalates,
alkyl salicylates and aryl benzoates of MP <20.degree. C.
Incorporation of such aromatic esters as at least a fraction of the
hydrophobic carrier liquid can be advantageous, because they can
raise the average refractive index of volatile-silicone-containi-
ng carriers, and thereby render it easier to obtain translucent or
transparent formulations.
[0069] 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 polygylcols such as an ether having named as
PPG-14 butyl ether by the CTFA.
[0070] Aliphatic alcohols which are liquid at 20.degree. C. and
boil at above 100.degree. C. provide an essential constituent of
the instant invention formulations, and especially desirably those
which are clearly water-immiscible. Such alcohols can often
constitute from 10% or 15% to 30% or 55% by weight of the cosmetic
composition.
[0071] Silicon-free liquids can constitute from 0-100% of the
residue of the water-immiscible liquid carrier, i.e. other than
said above-mentioned essential aliphatic alcohols, 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 to 60% by weight, eg 15 to 30% or 30
to 50% by weight, of the water-immiscible carrier liquid.
[0072] As will be explained in more detail below, in cosmetic
compositions herein, the structured water-immiscible carrier liquid
may be the continuous phase in the presence of a dispersed second
phase, which may comprise a suspension of particulate solid forming
a suspension stick or a dispersion of droplets of a lypohobic
liquid. Such a solid may be a particulate antiperspirant or
deodorant active or pigment. Such a disperse liquid phase may
comprise a solution of the aforementioned active or actives in
water or other hydrophilic ie lypophobic solvent.
[0073] As mentioned hereinabove, in accordance with the first
aspect, the invention requires a CDP structurant to structure a
carrier oil that comprises a monohydric alcohol. A cosmetic active
is present in cosmetic compositions and other materials may also be
present depending on the nature of the composition. The various
materials will now be discussed by turn and some preferred features
and possibilities will be indicated.
[0074] The proportion of the CDP structurant in a composition of
this invention is likely to be from 0.1 to 15% by weight of the
whole composition and preferably from 0.1 up to 10%. Its weight
proportion more commonly is at least 0.3% and in many instances not
more than 5%. In some especially desirable embodiments, the amount
of CDP structurant is from 0.5% to 3.5% or 5%. It will be
recognised that for any particular CDP, its maximum proportion in
the composition will vary in accordance with its solubility in the
selected monohydric alcohol and the conditions prevailing during
the dissolution process, such as temperature. Herein, unless other
wise stated, a % for the CDP is by weight based on the entire
composition.
[0075] If the composition is an emulsion with a separate disperse
phase, the amount of structurant compound(s) is likely to be from
0.3 to 20% by weight of the continuous phase, more likely from 0.6%
to 8% of this phase. In some highly desirable embodiments the
hydrophobic carrier continuous phase contains from 2 to 5% by
weight of the CDP.
[0076] Liquid Disperse Phase in Emulsions
[0077] If the composition is an emulsion in which the cyclo
dipeptide acts as a structurant in the hydrophobic continuous
phase, the emulsion will contain a more polar or lypophobic
disperse phase. The disperse phase may be a solution of an active
ingredient.
[0078] The hydrophilic disperse phase in an emulsion commonly
comprises water as solvent and can comprise one or more water
soluble or water miscible liquids in addition to or in replacement
of 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.
[0079] 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. Ethanol gives a cooling
effect on application to skin, because it is very volatile. It is
preferred that the content of ethanol or any other monohydric
alcohol with a vapour pressure above 1.3 kPa (10 mmHg) is not over
15% better not over 8% by weight of the composition.
[0080] 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.
[0081] 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 high proportion of disperse phase,
i.e. from 65 to 85% disperse phase, may be advantageous because
they can give good hardness even though the concentration of
structurant may be only a small percentage of the total
composition. However, compositions with a lower proportion of
disperse phase can also be advantageous because they tend to offer
a drier and warmer feel.
[0082] 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.
[0083] 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.
[0084] 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. C.sub.16 to
C.sub.18 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 Cl.sub.8-C.sub.22 fatty
alcohol ethers of polyethylene oxides (8 to 12 EO).
[0085] 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.
[0086] 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.
[0087] 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
PGPH.TM., Span.TM., Tween.TM., SF1228, DC3225C and Q2-5200.
[0088] Cosmetic Actives
[0089] The cosmetic actives employable herein can comprise
antiperspirant or deodorant actives or pigments.
[0090] Antiperspirant Actives
[0091] The composition preferably contains an antiperspirant
active. Antiperspirant actives, are preferably incorporated in an
amount of from 0.5-60%, particularly from 5 to 30% or 40%
and-especially from 5 or 10% to 30 or 35% of the weight of the
composition.
[0092] 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 and activated aluminium chlorohydrates.
[0093] Aluminium halohydrates are usually defined by the general
formula Al.sub.2(OH).sub.xQy.wH.sub.20 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.
[0094] Zirconium actives can usually be represented by the
empirical general formula: ZrO (OH).sub.2n-nzB.sub.z.wH.sub.20 in
which z is a variable in the range of from 0.9 to 2.0 so that the
value 2n-nz is zero or positive, n is the valency of B, and B is
selected from the group consisting of chloride, other halide,
sulphamate, sulphate and mixtures thereof. Possible hydration to a
variable extent is represented by wH.sub.20. 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.
[0095] The above aluminium and zirconium salts may have
co-ordinated 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.
[0096] 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.
[0097] 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.
[0098] Other actives which may be utilised include astringent
titanium salts, for example those described in GB 2299506A.
[0099] The proportion of solid antiperspirant salt in a suspension
composition normally includes the weight of any water of hydration
and any complexing agent that may also be present in the solid
active. However, when the active salt is incorporated in solution
in a hydrophilic solvent such as a glycol, its weight commonly
excludes any water present.
[0100] If the composition is in the form of an emulsion 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 disperse phase, particularly from 10% or 20%
up to 55% or 60% of that phase. Alternatively, the composition may
take the form of a suspension in which antiperspirant active in
particulate form is suspended in the water-immiscible liquid
carrier. Such a composition will probably not have any separate
aqueous phase present and may conveniently be referred to as
"substantially anhydrous" although it should be understood that
some water may be present bound to the antiperspirant active or as
a small amount of solute within the water-immiscible liquid phase.
In such compositions, the particle size of the antiperspirant salts
often falls within the range of 0.1 to 200 .mu.m with a mean
particle size often from 3 to 20.mu.m. Both larger and smaller mean
particle sizes can also be contemplated such as from 20 to 50.mu.m
or 0.1 to 3.mu.m.
[0101] Deodorant Actives
[0102] 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 Igasan DP300.TM. (triclosan), Tricloban.TM., and
Chlorhexidine warrant specific mention. A yet another class
comprises biguanide salts such as are available under the trade
mark Cosmosil.TM.. Deodorant actives are commonly employed at a
concentration of from 0.1 to 25% by weight.
[0103] Optional Ingredients
[0104] 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.
[0105] A further optional constituent of the formulation comprises
one or more further structurants which can be employed in addition
to the cyclo dipeptide. Herein, the CDP may be the primary
structurant, by which is meant that is employed at a concentration
that is higher than that of the further structurant. However, in
some advantageous embodiments, the further structurant may be
present in an amount that is at least that of the CDP. In such
advantageous embodiments, the CDP is acting to moderate the
properties of the further structurant such that the properties
using the combined structurant system are superior in at least one
desirable respect to using the further structurant alone. The
amount of such further structurants in the formulation is often
from zero to not more than 15% of the formulation. In some
instances, the further structurant is present in a weight ratio to
the CDP of from 10:1 to 1:10.
[0106] The further structurants employable herein can be
non-polymeric or polymeric. Solid linear fatty alcohol and/or a wax
may be included but are not preferred. In anhydrous compositions
notably antiperspirants which are suspension sticks, non-polymeric
further structurants, sometimes referred to as gellants, can be
selected from fatty acids or salts thereof, such as stearic acid or
sodium stearate or 12-hydroxy stearic acid. Linear fatty acids are
preferably not used in aqueous sticks, e.g. aqueous emulsion sticks
because they can form insoluble precipitates with aluminium ions.
Other suitable gellants can comprise dibenzylidene alditols, e.g.
dibenzylidene sorbitol. Further suitable gellants can comprise
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. When employing further structurants
comprising N-acyl amino acid derivatives, in some highly desirably
formulations their weight ratio to CDP is selected in the range of
1:1 to 6:1.
[0107] Polymeric structurants which can be employed as further
structurants 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.
[0108] It is highly desirable that any further structurant employed
herein is itself fibre-forming, that is to say forms a fibrous
structure within the hydrophobic phase. Most preferably the
fibre-forming structurant is one in which the fibrous structure is
not visible to the human eye.
[0109] Fatty alcohols which are solid at room temperature of
20.degree. C., such as linear monohydric alkanols containing at
least 12 carbons e.g. stearyl alcohol or behenyl alcohol, lead to
deposits with an opaque white appearance and are preferably
substantially absent, by which we mean present in an amount of no
more than 3% by weight of the composition, more preferably less
than 1% and most preferably are not incorporated specifically, ie
0%. As already mentioned, fatty alcohols are often regarded as
coming within the general category of waxy materials. More
generally the term "wax" is conventionally applied to a variety of
materials and mixtures (including some fatty alcohols) which have
some diversity in chemical structure but similarity in physical
properties. The term generally denotes materials which are solid at
30.degree. C., often also solid up to 40.degree. C., having a waxy
appearance or feel, but which gradually soften and eventually melt
to a mobile liquid at a temperature below 95.degree. C. usually
below 90.degree. C.
[0110] Possibly the composition does not include more than 3% of
any material which is a wax, ie a solid at 30.degree. C. but
softens at an elevated temperature and at 95.degree. C. is molten
and soluble in the water-immiscible liquid, yet which is unable to
form a network of fibres therein on cooling to 20.degree. C.
[0111] The compositions herein can incorporate one or more cosmetic
adjuncts in amounts conventionally contemplatable for cosmetic
solids or soft solids. Such cosmetic adjuncts can include skin feel
improvers, such as small particle inorganic mineral substances like
talc, finely divided silica and/or bentonite or similar clays, 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.
[0112] Product Form
[0113] The sticks produced employing the CDP structurants can be
either opaque or translucent or even transparent, depending at
least partly on the extent to which the refractive indices (RI) of
the appropriate ingredients are matched. Translucent or transparent
formulations are possible in respect of the invention formulations
because the CDP structurant forms a fibrous structure within the
liquid hydrophobic carrier that is not seen by the human eye. By
matched herein is meant that the difference between the refractive
indices is less than 0.005 and preferably less than 0.002. In
suspension sticks, to achieve at least translucency without using
exclusively sub-micron sized particles, it is necessary to match
the RI of the suspended cosmetic active, eg the particulate
antiperspirant salt, with the RI of the suspending carrier oil
mixture. This can be assisted by a suitable choice of oils, and in
particular mixtures containing those having an RI of above 1.46,
such as from 1.46 to 1.56. In regard to the suspended particulates,
RI matching can be assisted by controlling the particle size
distribution, and particularly by not permitting an excess
proportion of 1 to 10 micron particles and advantageously by
avoiding the manufacture of hollow sphere antiperspirant actives or
subsequently removing the hollows. Matching can be further assisted
by modifying the RI of the suspended cosmetic active, such as an
aluminium-containing antiperspirant active by post treating it with
water (re-hydration) or by retaining a comparatively high water
content during the manufacture process. In emulsion formulations,
the relevant ingredients to RI match comprise the disperse and
continuous liquid phases.
[0114] It is highly desirable to employ RI matching as indicated
above in conjunction with the exclusion, to the extent necessary,
of additional suspended materials having a different refractive
index from the suspending medium, such as for example a suspended
filler or additional cosmetic active, to enable the resultant
composition to transmit at least 1% light (in the test described
hereinafter).
[0115] Mechanical Properties and Product Packages
[0116] The compositions of this invention are structured liquids
and are firm in appearance. 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 an
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 at one end of the barrel.
[0117] 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 often closed.
[0118] 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 hand-wheel mounted on the barrel
at its closed end, i.e. the opposite end to the delivery
opening.
[0119] 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.
[0120] Composition Preparation
[0121] Compositions of this invention can be produced by process
similar to conventional processes for making cosmetic solids. Such
processes involve forming a heated mixture of the structurant in
the carrier oil, in this case the monohydric alcohol and optionally
together with a fraction or even all of any other oil, at a
temperature which is sufficiently elevated that all the 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 fibres
extending through the water-immiscible liquid phase. The employment
of the monohydric alcohol in the continuous carrier enables the
benefits of higher CDP concentration and reduced gelling
temperature to be attained
[0122] A convenient process sequence for a composition which is a
suspension comprises first forming a solution of the structurant in
the monohydric alcohol and optionally a fraction of or even all the
water-immiscible liquids. This is normally carried out by agitating
the mixture at a temperature sufficiently high that all the
structurant dissolves (the dissolution temperature) such as a
temperature in a range from 50 to 140.degree. C. Thereafter, the
particulate constituent, for example particulate antiperspirant
active, is blended with the hot mixture. This may be done slowly,
and/or the particulate solid preheated, in order to avoid premature
gelation. The resulting blend is then introduced into a dispensing
container such as a stick barrel. This is usually carried out at a
temperature 5 to 30.degree. C. above the setting (gelling)
temperature of the composition. The container and contents are then
cooled to ambient temperature. Cooling may be brought about by
nothing more than allowing the container and contents to cool.
Cooling may be assisted by blowing ambient or even refrigerated air
over the containers and their contents.
[0123] In a suitable procedure for making emulsion formulations, a
solution of the structurant in the continuous carrier 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). If possible, 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 it is necessary to work at a
temperature above the boiling temperature of the disperse phase, or
at a temperature where evaporation from this phase is significant,
a pressurised apparatus could be used to allow a higher temperature
to be reached. 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 as described above for suspension
sticks.
[0124] Many of the cosmetic compositions according to the present
invention employ a mixture of at least one hydrophobic cosmetic oil
(carrier fluid) with the monohydric alcohol. In some convenient
preparative routes, it is desirable to dissolve the CDP structurant
in the alcohol, optionally in conjunction with a minor proportion
of an alcohol having some water-miscibility and boiling point above
the dissolution temperature of CDP in the alcoholic fluid. This
enables the remainder of the carrier fluids to avoid being taken to
the temperature at which the CDP dissolves or melts. The proportion
of the carrier fluids for dissolving the CDP is often from 15 to
85% by weight of the carrier fluids, and particularly from 20 to
40% or 70%. In one variation, the CDP structurant is first
dissolved by heating to an elevated temperature with stirring in a
mixture comprising the monohydric alcohol plus up to a quarter or
even up to half of the total of any water-immiscible cosmetic oil
employed in the composition, and there after mixing the solution of
the CDP with the remainder of the cosmetic oil and the cosmetic
active, such a particulate antiperspirant or an aqueous solution of
an antiperspirant. The remainder of the cosmetic oil and of the
cosmetic active are taken to a suitable temperature such that the
temperature of their mixture with the CDP solution is still above
the gelling temperature of the composition, preferably no more than
5 or 10.degree. C. above the gelling temperature, which may have
been determined in a previous trial.
[0125] Structurant Preparation
[0126] CDP structurants can be made by one or more of the general
preparative routes published in the above-identified papers by
Hanabusa with appropriately chosen reagents to obtain the desired
substituent groups R.sub.1 and R.sub.2 of the cyclo dipeptide,
and/or by variations described hereinbelow or the general method
described herein to make the materials CDP1 to CDP13.
[0127] One route of general applicability described by Hanabusa
comprises the cyclisation of dipeptide ethyl esters under reflux in
1,3,5-trimethyl benzene, the esters being obtained by catalytic
hydrogenation of the corresponding N-benzoylcarbonyl dipeptide
ethyl ether with 10% Pd-C. In a variation thereof, ester groups in
an existing ester CDP can be replaced in a conventional
transesterification process in the corresponding alcohol, eg
3,7-dimethyloctanol. Various of the CDPs are derivable indirectly
from aspartame by esterifying cyclo[(R)-phenylalanyl] that is
obtainable by heating aspartame, preferably in the presence of a
substantial excess of a low molecular weight aliphatic alcohol,
such as isopropanol, under reflux for a long period. Desirably, the
alcohol is employed in a weight ratio to aspartame of greater than
50:1 such as up to 100:1, and the reaction is continued for at
least 10 hours at reflux temperature, such as from 15 to 24 hours.
During the reaction, the aspartame gradually dissolves. On cooling,
the resultant solution yields a white powder. Removal of the
solvent from the filtrate yields a solid which, after washing with
acetone, provides a further amount of the white product, confirmed
by a combined yield of the CDP precursor acid of 79%.
[0128] The precursor acid can be reacted with the relevant alcohol
of formula R.sub.AOH, preferably in a mole ratio to the precursor
of at least 1:1 to 10:1, particularly from 1.5:1 to 7:1 and
especially at least 2:1 in dimethyl sulphoxide, conveniently in a
ratio of at least 4:1 (vol:wt), preferably from 6:1 to 12:1, and
preferably in the presence of a promoter, such as a
carbonyldiimidazole, in an amount preferably from 0.5 to 2 moles of
promoter per mole of precursor acid. The reaction is conveniently
carried out at a mildly elevated temperature, such as up to
60.degree. C. and particularly from 40 to 60.degree. C. for a
period of at least 6 hours and preferably from 9 to 24 hours. The
resultant solution is quenched in excess ambient or cooler water,
desirably after the solution has cooled to ambient, a solid
precipitates and is filtered off, water washed until no residual
diimidazole remained and then can be purified by washing with
diethyl ether or toluene, and dried.
EXAMPLES
[0129] Preparation of CDP Structurants
[0130] The cyclo dipeptide structurants employed in the following
Examples and Comparisons were made by the following general method
employing (2S-cis)-(-)-5-benzyl-3,6-dioxo-2-piperazine acetic acid
(DOPAA) which was reacted with the alcohols specified in Table 1
below.
[0131] A 250 ml 3 necked round bottomed flask equipped with a
stirrer was charged with
(2S-cis)-(-)-5-benzyl-3,6-dioxo-2-piperazine acetic acid (DOPAA)
(18.4 mmol), and dimethyl sulfoxide (8mls per 1 g of DOPAA) was
then introduced at laboratory ambient temperature (about 22.degree.
C.) with stirring. The DOPAA dissolved only partially.
1,1'-carbonyldiimidazole (22 mmol) was then introduced with
stirring in the amount specified in the Table. Vigorous
effervescence occurred and the react mixture was left stirring at
room temperature for 45 minutes after which time the reaction
mixture went clear. The specified alcohol (92 mmol) was stirred
into the clear reaction mixture and maintained at 50.degree. C.
overnight (between 16 and 20 hours), whereupon it was allowed to
cool to ambient temperature (about 22.degree. C.), and poured into
water, producing a precipitate which was filtered off and washed
with further quantities of water until any residual diimidazole had
been removed (as shown by .sup.1Hnmr). The washed precipitate was
then washed with diethyl ether. The washed product was dried in a
vacuum oven to constant weight and its melting point determined,
the results quoted herein being obtained by DSC with a heating rate
of 10.degree. C./min, except for those marked .sup.ET, which were
obtained using a an Electrothermal 9109 digital melting point
measuring apparatus.
1TABLE 1 Purity Melting CDP Alcohol % Point .degree. C. CDP1
(1S,2R,5S)-(+) Menthol 98.7 238 CDP2 Thymol 99.3 212 CDP3
1R,2R,3R,5S-(-)-iso- 68 >200 pinocamphenol CDP4
3,5-dimethyl-cyclohexanol 94 212 CDP5 phenol 99.7 246 CDP6
butyl-4-hydroxy benzoate 98.5 217 CDP7 iso-propanol 98.5 215 CDP8
n-propanol 98.2 >200 CDP9 4-t-butylphenol 99.1 237 CDP10 carveol
65.0 215.sup.ET CDP11 carvacrol 99.1 229.sup.ET CDP12
5,6,7,8-tetrahydronaphth-2-ol 99.3 220.sup.ET CDP13
2-isopropoxyphenol 98.8 178.sup.ET
[0132] Materials
[0133] The materials used in gel studies or the preparation of
cosmetic formulations, and their proprietary names, other than the
structurants CDP1 to CDP9, are summarised in Table 2:
2 TABLE 2 Abrev CFTA name Trade Name/supplier Monohydric Alcohols 1
ISA Isostearyl Alcohol Pricerine 3515 .TM. - Uniqema 2 ODA Octyl
Dodecanol Eutanol G .TM. - Cognis 3 BMA Benzyl Alcohol Acros 4 8MA
octyl Alcohol Sigma 5 10MA decyl Alcohol Sigma 6 ICA iso-cetyl
Alcohol Eutanol G16 - Cognis Water-immiscible oil 7 TN C.sub.12-15
alkyl Finsolv TN .TM. from Finetex benzoate Inc 8 245
Cyclomethicone DC 245 .TM. - Dow Corning Inc 9 364 Hydogenated
Silkflo 364 NF .TM. - Albemarle Polydecene 10 704
1,1,5,5-tetraphenyl DC704 .TM.: Dow Corning Inc trisiloxane
Auxiliary Structurant 11 GP1 N-lauroyl-L- Gp-1 .TM.Ajinomoto Co Inc
glutamic acid Di-n- butylamide 18 DBS dibenzylidene Roquette
sorbitol 19 HSA 12-hydroxystearic 12-HSA (CasChem) acid 20 930
Polyamide Versamid 930 .TM. (Cognis) Emulsifier 12 EM90 Dimethicone
Abil EM90 .TM. - Th. Goldschmidt Copolyol AG 21 P135 dipolyhydroxy-
Arlacel p135 .TM. (Uniquema) stearate Cosmetic Active 13 R908 Al/Zr
Reach 908 .TM. - Reheis Inc Tetrachlorohydrex glycine complex 14
A418 Milled A418 .TM. - Summit Macrospherical AACH 15 Z50 50%
aqueous Zirconal 50 .TM. - BK Giulini solution of Al/Zr
pentachlorohydrate 16 R67* Water-modified Rezal 67 .TM. modified
in-house AZAG 22 36GP solid Al/Zr tetra- Rezal 36GP .TM. Reheis Inc
chlorhydrex glycine 23 P5G Al/Zr pentachloro- P5G .TM. (BK Giulini)
hydrex glycine complex (RI 1.530) Water-miscible liquids 17 GOH
Glycerin Glycerol - Aldrich 24 PG propane-1,2-diol Fisher 25 DPG
di(propane-1,2- Fisher diol) 26 TPnB tri(1,2-propane- Dowanol TPnB
.TM. - Dow Corning diol) n-butylether Inc Other Ingredients 27 H30
silica H30 .TM. - Wacker-Chemie GmbH 28 H30R silica H30RX .TM. -
Wacker-Chemie GmbH X 29 H18 silica H18 .TM. - Wacker-Chemie GmbH
16--R67* was made in house by freeze drying an AZAG solution (Rezal
67 .TM.) and sieving to obtain particulate solid free from hollow
particles (.about.37% of particles <10 .mu.m) and water treated
to RI = 1.526. 23--P5G was free from hollow particles and contained
.about.25% particles of <10 .mu.M)
Example 1
[0134] Structured Gels
[0135] In this Example, gels were made or attempted to be made in a
number of representative organic solvents, using the structurants
CDP1 to CDP13.
[0136] The gels were prepared in 30 ml clear glass bottles. The
solvent and gelling agent were weighed directly into the bottle to
give a total mixture weight of 10 g. A small Teflon.TM. stirrer bar
was placed in the bottle and the mixture stirred and heated until
the cyclo dipeptide had dissolved. The bottle was then removed from
the heat and the solution allowed to cool and gel under quiescent
conditions.
[0137] The ease of gel formation was assessed by determining for
each of the cosmetic base formulations the temperature at which the
CDP structurant dissolved in the chosen oil(s) and if dissolution
was observed, the temperature at which a gel formed on cooling the
formulation. The results are summarised in Table 3.
[0138] These Examples and comparisons demonstrate the relative ease
or difficulty of forming gelled cosmetic base formulations,
depending on which oils are employed during the dissolution of the
CDP structurant and the subsequent formation of a gel as the
composition cools. The results are representative of corresponding
formulations in which a cosmetic active is also introduced.
3 TABLE 3 Example/Comp 1.1 1.2 1.3 1.4 1.5 1.6 1.7 C1.1 C1.2 C1.3
C1.4 Ingredients % by weight CDP1 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5
1.5 1.5 1.5 1-ISA 98.5 49.25 49.25 49.25 49.25 2-ODA 98.5 3-BMA 7.4
7-TN 49.25 98.5 8-245 49.25 98.5 9-364 49.25 98.5 10-704 49.25 91.1
98.5 Gel Formed? yes yes yes yes yes yes yes no yes yes no Diss'n
Temp .degree. C. 120 131 138 105 125 123 148 dnd 142 .about.150 dnd
140 Gelling Temp .degree. C. 35 65 65 43 41 46 75 -- 79 126 --
Example/Comp 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18
1.19 1.20 Ingredients % by weight CDP2 1.5 1.5 1.5 1.5 1.5 1.5 1.5
1.5 1.5 1.5 1.5 3.75 4.0 1-ISA 98.5 49.25 49.25 49.25 24.62 49.25
12.02 26.88 2-ODA 24.62 3-BMA 7.4 12.02 9.60 4-8MA 24.62 5-10MA
24.62 6-ICA 98.5 7-TN 49.25 6.72 8-245 49.25 52.8 9-364 49.25
10-704 49.25 73.88 73.88 73.88 73.88 91.1 72.21 Properties Gel
Formed yes yes yes yes yes yes yes yes yes yes yes yes yes Diss'n
Temp .degree. C. 111 115 137 127 136 118 114 114 134 136 130 119
130 Gellng Temp .degree. C. 29 33 58 50 58 25 30 28 62 56 61 55 66
Example/Comp 1.21 1.22 C1.5 C1.6 C1.7 C1.8 1.23 C1.9 1.24 1.25 1.26
1.27 Ingredient % by weight CDP2 15.0 3.0 1.5 1.5 1.5 3.75 CDP5 1.5
1.5 CDP6 1.5 1.5 1.5 1.5 1-ISA 51.0 19.4 98.5 49.25 49.25 3-BMA
34.0 9.7 24.62 14.77 8-245 98.5 7-TN 98.5 49.25 9-364 10-704 67.9
98.5 98.5 73.88 98.5 49.25 83.73 Properties Gel Formed? yes yes yes
no yes yes yes no yes yes yes yes Diss'n Temp .degree. C. 123 130
133 dnd 148 dnfd 134 dnd 140 145 130 140 135 Gelling Temp .degree.
C. 69 70 84 98 .about.120 69 -- 62 86 78 76 Example/Comp C1.10
C1.11 1.28 1.29 1.30 1.31 1.32 1.33 1.34 1.35 C1.12 1.36 1.37 C1.13
Ingredient % by weight CDP6 1.5 1.5 CDP7 1.5 1.5 CDP8 1.5 CDP3 1.5
1.5 CDP4 1.5 CDP10 1.5 1.5 1.5 CDP11 1.5 1.5 1.5 1-ISA 98.5 24.62
98.5 98.5 49.25 98.5 98.5 24.62 98.5 3-BMA 24.62 7-TN 98.5 49.25
9-364 10-704 98.5 73.88 73.88 98.5 73.88 98.5 Properties Gel
Formed? yes yes yes yes yes yes yes yes yes yes yes yes yes yes
Diss'n Temp .degree. C. dnfd dnfd 113 134 107 138 150 130 111 139
dnfd 110 90 146 Gelling 143 120 45 77 49 25 39 57 38 66 94 98 25
118 Temp .degree. C. Composition (%) 1.38 C1.14 1.39 1.40 C1.15
1.41. C1.16 1.42 C1.17 1.43 C1.18 CDP12 1.5 1.5 CDP13 1.5 1.5 1.5
CDP14 1.5 1.5 CDP15 0.5 0.5 1.5 1.5 1-ISA 98.5 24.62 99.5 3-BMA
24.62 24.62 24.62 10-704 73.88 98.5 73.88 98.5 73.8 98.5 99.5 73.88
98.5 Gel Formed yes yes yes yes yes yes no yes no yes no
Dissolution 121 dnfd 85 95 102 148 DND 129 DND 128 DND Temperature
(.degree. C.) 150 Gelling 58 128 25 25 79 95 42 75 Temperature
(.degree. C.)
[0139] In Table 3 above, dnd indicates that the structurant did not
dissolve, and dnfd that it did not fully dissolve, in each case at
150.degree. C. unless otherwise indicated.
[0140] From Table 3, it can be seen that the employment of the
specified monohydric alcohols, viz materials (1) to (6), enabled
the resultant composition to gel at a lower temperature. Thus, for
example, a comparison of Ex 1.2 with C1.1 shows that the CDP
dissolved in the invention mixture at 131.degree. C., but had not
dissolved at 140.degree. C. in solely the volatile silicone.
Similar improvements can be seen by comparing Ex 1.3 or 1.4 with
C1.4 and C1.3 respectively. Of course, where the structurant had
not dissolved, it could not subsequently form a distributed network
through the carrier liquid and hence was not able to form a gel.
Where it did dissolve, though at a higher temperature as in C1.3,
the composition gelled at a much higher temperature of
significantly over 100.degree. C. compared with the gelling
temperature of the directly comparable invention composition, Ex
1.3. Ex 1.21 shows the formation of a concentrated solution/gel
that can subsequently be diluted with other cosmetic oils during
stick preparation.
Examples 2 to 5
[0141] Cosmetic Stick Formulations
[0142] A number of cosmetic stick compositions were prepared,
containing the ingredients specified in Tables 4 to 10 below. Their
properties were measured by the methods described hereinafter and
at the times indicated in the summaries.
Example 2
[0143] Opaque Suspension Sticks
[0144] In Example 2, opaque sticks were made by dissolving the
specified cyclo dipeptide structurant in isostearyl alcohol whilst
with heated and stirring using an overhead paddle stirrer until
complete dissolution had occurred. In formulations additionally
containing GP1, the latter was dissolved into solution of the cyclo
dipeptide structurant at a temperature of about 5 to 10.degree. C.
lower. The remaining carrier oils were heated to approximately
50.degree. C. and stirred using a stirrer bar and the desired solid
antiperspirant active was introduced slowly and with gentle
stirring into them. When all the active had been added, the mixture
was sheared using a Silverson mixer at 7000 rpm for 5 minutes to
ensure the active was fully dispersed. The active/oil mixture was
then heated in an oven to 85.degree. C. and mixed into the
structurant solution which had been allowed to cool to 90.degree.
C. The temperature of the stirred mixture was kept at 85.degree. C.
until it was poured into conventional commercial 50 g stick barrels
and allowed to cool except for formulations containing GP1 which
were poured at approximately 75.degree. C.
[0145] The formulations and properties of the sticks are summarised
in Table 4 below.
4TABLE 4 Example No 2.1 2.2 2.3 2.4 2.5 Ingredient % by weight CDP2
2.5 2.5 1.5 1 CDP3 1.5 1.ISA 35.75 35.75 30 28.2 30 7 TN 35.75 20.9
8.245 20.9 10.704 35.75 40 40 11.GP1 2.5 3.0 2.5 13.R908 26.0 26.0
26.0 26.0 26.0 Properties Hardness (mm) 16.5 15.2 13.8 18.6 14.3
pay.off (g) at t.sub.o 0.35 0.25 0.31 0.27 0.3 on WetorDry
whiteness t = 24 hr 13 16 14 27 20 on WetorDry pay.off (g) at
t.sub.o 0.99 0.63 0.82 0.63 1.08 on wool whiteness t = 24 hr 17 17
16 15 20 on wool
[0146] From Table 4, it can be seen that sticks of acceptable
firmness can be obtained using the invention structurants at
comparatively low concentrations of the structurant and also in the
presence of an additional structurant, also at a low
concentration.
Example 3
[0147] Transparent Suspension Sticks
[0148] The sticks in this Example were made using the process of
Example 3 together with a preparatory step. In the preparatory
step, the RI of the antiperspirant active was first measured using
a standard procedure (Becke line test). The proportions of each of
the carrier oils were then determined (through calculation and
measurement) such that their weight averaged refractive index was
closely matched to that of the active. In Example 3.8, the CDP
structurant was fully dissolved in the mixture of monohydric
alcohols before being mixed with the remainder of the carrier oils
and subsequently with the antiperspirant active. The formulations
are summarised in Table 5 below.
5TABLE 5 Example No 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Ingredient
% by weight CDP2 1.51 1.5 1.5 1.0 2.81 CDP4 0.70 CDP1 1.0 CDP5 1.5
CDP9 3.0 1-ISA 18.34 17.61 17.36 17.55 17.61 17.36 16.71 8.81 3-BMA
8.81 19.68 7-TN 12.21 22.83 10-704 55.03 52.89 52.14 52.7 52.89
52.14 54.29 42.36 29.47 11-GP1 3.0 4.0 4.05 3.5 4.0 3.0 14-A418
25.12 25.0 25.0 25.0 25.0 25.0 25.0 25.0 16-R67* 25.0 Hardness mm
23 14.7 13.1 16.1 14.8 n/d 16.2 14.0 20.1 Clarity % T 44 12.7 15.4
12.0 9.9 1.6% 0.7 23.0 6.1 Example No 3.10 3.11 3.12 3.13 3.14 3.15
3.16 3.17 3.18 Ingredient % by weight CDP2 1.5 1.7 1.5 1.5 1.7 2.0
CDP10 1.0 CDP11 0.7 CDP12 0.4 11-GP1 2.0 4.0 2.0 2.0 4.0 4.0 4.0
18-DBS 0.25 0.4 19-12-HSA 5.0 1-ISA 17.8 18.46 15.51 15.735 16.14
17.98 15.848 15.916 15.32 10-704 53.45 52.48 52.99 53.765 55.16
51.1 54.152 54.384 53.30 3-BMA 1.96 1.92 1.98 7-TN 14-A418 25.0
25.0 25.0 25.0 25.0 25.0 25.0 23-PSG 25.0 25.0 Properties Hardness
mm 13.5 17.2 13.3 12.1 14.4 14.2 13.7 14.2 16.9 Clarity % T 19.4
15.3 12.2 2.2 13.2 26.6 27.5 15.0 8.7 Clarity- 2 3 0 -9 7 6 4 1 0
visual score
[0149] From Table 8, it can be seen that clear cosmetic sticks are
obtainable using various combinations of oils as continuous carrier
phase together with the CDP structurants, either alone or with a
co-structurant.
Example 4
[0150] Opaque Emulsion Sticks
[0151] In a first step in making opaque emulsion sticks according
the present invention, a solution of the selected invention
structurant, and if present GP1, in ISA was made by the same method
as in the process for making suspension sticks (Example 3). The
remaining water immiscible carrier oils together with an
emulsifier, Abil EM 90, were heated to 85.degree. C. in an oil bath
whilst being shear mixed at 2500 rpm. The solution of
antiperspirant active was heated to 80.degree. C. and introduced
gradually into the oil/emulsifier mixture, and the resultant
mixture was kept constant by heating at 85.degree. C. and sheared
at 7500 rpm for 5 minutes. The emulsion was the mixed into the
solution of the structurant solution which had been allowed to cool
to .about.90.degree. C. The resultant mixture was stirred briefly
to achieve complete mixing, poured into commercial 50 g stick
barrels at approximately 80.degree. C. and allowed to cool. The
formulations and properties of the sticks are summarised in Table 9
below.
6 TABLE 6 Example No 4.1 4.2 Ingredient % by weight CDP1 1.5 CDP2
1.5 1-ISA 29.0 27.0 7-TN 29.0 27.0 11-GP-1 4 12-EM90 0.5 0.5 15-Z50
40.0 40.0 Properties Hardness (mm) 27.8 17.1 pay-off (g) at t.sub.o
on wool 0.66 0.80 whiteness t = 24 hr on wool 17 18
[0152] From Table 6, it can be seen that the use of the monohydric
alcohol in conjunction with the other water-immiscible oils enables
the emulsion formulations to be made quite easily.
Example 5
[0153] Clear Emulsion Stick
[0154] In this Example, the general method of making emulsion
sticks described in Example 5 was followed, preceded by a
preparatory step for refractive index matching in order to obtain a
translucent emulsion stick.
[0155] In the preparatory step, the refractive indices of the
ingredients of the organic and aqueous phases in the emulsion were
obtained or measured, and proportions of those ingredients
estimated, based on calculation and measurement, such that the two
phases had roughly matched refractive indices. The two phases
containing the estimated proportions of ingredients were prepared,
their refractive indices measured and the proportions of the
carrier oils in the continuous (water-immiscible) phase were
adjusted to the extent necessary to more closely match the RI of
the disperse aqueous phase. In Example 5.2, the CDP structurant was
fully dissolved in the mixture of monohydric alcohols before being
mixed with the remainder of the carrier oils and subsequently with
the antiperspirant active.
[0156] The Versamid polymer when employed was dissolved
simultaneously with the cyclic dipeptide structurant. Any silica
was incorporated in suspension in a fraction of the
water-immiscible oil(s) and any antiperspirant active supplied as a
solid was first dissolved in the specified weight of water.
[0157] The formulation and its properties are summarised in Table 7
below, in which nd indicates that a particular test was not carried
out.
7 TABLE 7 Example No 5.1 5.2 5.3 5.4 5.5 Ingredient % by weight
CDP2 1.5 2.0 2.0 1.5 2.0 1-ISA 21.14 12.84 18.51 20.92 43.45 3-BMA
4.61 7-TN 5.71 8.22 5.05 5.65 8-245 21.14 26.83 20.44 20.93 11.77
12-EM90 0.5 0.5 1.0 1.0 0.49 15-Z50 40.0 40.0 40.0 40.0 water 16.52
22-36GP 24.77 17-GOH 10.0 10.0 10.0 10.0 Fragrance 1.0 Properties
Hardness mm 18.6 16.1 13.4 11.9 17.2 Clarity % T 6.7 1.9 n/d n/d
n/d Clarity 1 nd n/d n/d n/d (visual score) Example No 5.6 5.7 5.8
5.9 5.10 Ingredients % by weight CDP2 2.0 2.0 2.0 1.5 1.5 1-ISA
42.66 41.08 43.05 20.6 21.65 7-TN 5.55 3.95 8-245 11.56 11.14 11.67
20.60 21.65 17-GOH 10.0 10.0 15-Z50 40.0 40.0 water 17.58 17.78
17.78 22-36GP 23.71 23.71 13-R908 23.71 12-EM90 0.49 0.49 0.49 0.75
0.75 20-930 1.0 2.0 1.0 1.0 27-H30 0.50 28-H30RX 1.0 2.0 29-H18 0.5
Properties Hardness (mm) 14.4 19.9 17.2 14.8 14.7 Clarity (% T)
42.0 19.0 58.4 0.82 0.74 Clarity (visual 4 -1 7 n/d n/d score)
[0158] From Table 7 it can be seen not only that clear emulsion
sticks can be made that include a faction of a water-miscible
liquid, glycerol, but also that it can be made easily employing
prior dissolution of the structurant in the monohydric
alcohols.
[0159] Test Methods
[0160] i) Purity of CDP
[0161] The purity of CDP materials Al to A9 was measured by reverse
phase HPLC with ultraviolet (UV)detection.
[0162] A mobile phase was made comprising 300ml aliquot of
deionised water, to which was added a 700ml aliquot of HPLC grade
acetonitrile and 1.0 ml of trifluoroacetic acid (Aldrich
spectrophotometric grade, TFA) and mixed thoroughly. 0.00 lg of CDP
sample was weighed into a 2 ml HPLC vial and made up to volume with
the mobile phase.
[0163] The sample was then analysed in a Hewlett Packard HPLC
analyser equipped with a Hypersil ODS 5.mu.m C.sub.18,
250.times.4.6mm @ Room Temp column, a Hewlett-Packard 1050 Series
Autosampler and Hewlett-Packard 1050 UV Diode Array @ 210nm
Detector. The analysis was carried under the following
conditions
8 Isocratic/gradient Isocratic Flow rate 1.2 ml/minute Run time 5
minutes Temperature Ambient Injection volume 20 .mu.l
[0164] ii) Dissolution Temperature
[0165] The dissolution temperature of the CDP was determined by
forming a mixture of the particulate CDP and the selected carrier
liquid at ambient temperature keeping the particulates in
suspension with a mixer bar and raising the temperature of the
mixture at a rate that was initially faster and later of
approximately 2.degree. C. per minute as the dissolution
temperature was approached more closely. The dissolution
temperature was assessed as the temperature at which particulates
were no longer visible.
[0166] iii) Gelling Temperature
[0167] The gelling temperature of a gelled oil phase was determined
by first preparing a solution of the CDP in the selected oil(s) in
glass tubes, having a diameter of 20mm and equipped with a glass
thermometer resting on the bottom of the tube, in accordance with
the description for Example 1 herein, and thereafter permitting the
resultant solution in the tubes to cool naturally under quiescent
conditions, ie without any cooling air being blown over the tubes
and without the solution being stirred. External laboratory air
temperature was about 23.degree. C. Periodically, the thermometer
was lifted by a few mm and if liquid had not flowed to fill the
void under gravity, was carefully replaced on the tube bottom. The
solution was considered to have formed a gel when it did not flow
underneath the thermometer.
[0168] Stick Characterisation--Measurement of Properties
[0169] iv) Stick hardness--Penetrometer
[0170] 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.
[0171] 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. 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 5mm to 20 mm.
[0172] 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.
[0173] v) Deposition by firm sticks (pay-off)
[0174] Another property of a composition is the amount of it which
is delivered onto a surface when the composition is drawn across
that surface (representing the application of a stick product to
human skin), sometimes called the pay-off. To carry out this test
of deposition when the composition is a firm stick, able to sustain
its own shape, 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. A specific
procedure for such tests of deposition and whiteness applicable to
a firm solid stick 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.
[0175] The substrates used were:
[0176] a: 12.times.28cm strip of grey abrasive paper (3M.TM. P800
WetorDry.TM. Carborundum paper)
[0177] b: 12.times.28cm strip of black Worsted wool fabric.
[0178] The substrates were weighed before use. The sticks were
previously unused and with domed top surface unaltered.
[0179] 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.
[0180] 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. The whiteness of the deposit could subsequently
be measured as described at (v) below.
[0181] vi) Whiteness of Deposit
[0182] The deposits from the at test (ii) above, were assessed for
their whiteness shortly after application (ie within 30 minutes) or
after an interval of 24 hours approximately.
[0183] This was done using a Sony XC77 monochrome video camera with
a Cosmicar 16mm focal length lens positioned vertically above a
black table illuminated from a high angle using fluorescent tubes
to remove shadowing. The apparatus was initially calibrated using a
reference white card, after the fluorescent tubes had been turned
on for long enough to give a steady light output. 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.TM. image analyser. This notionally divided the image
into a large array of pixels and measured the grey level of each
pixel on a scale of 0 (black) to 255 (white). The average of the
grey intensity was calculated. This was a measure of the whiteness
of the deposit, with higher numbers indicating a whiter deposit. It
was assumed that low numbers show a clear deposit allowing the
substrate colour to be seen.
[0184] vii) Clarity of formulation--Light transmission
[0185] 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.
[0186] This test was carried out using a dual-beam Perkin Elmer
Lambda 40 spectrophotometer. The sample of composition was poured
hot into a 4.5 ml cuvette made of poly(methyl-methacrylate) (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. 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.
[0187] viii) Clarity of Formulation--Visual assessment score
[0188] A gel contained within a 1 cm thick cuvette was placed
directly on to a sheet of white paper on which 21 sets of figures
where printed in black. The size and thickness of the figures
varied systematically and were numbered from -12 (the largest,
thickest set) through 0 to 8 (the smallest thinnest set) The score
given to each gel was the highest numbered set which could be read
clearly through the gel, the higher the number, the higher the
clarity.
* * * * *