MXPA99004548A - Antiperspirant cosmetic composition - Google Patents

Abstract

A suspension antiperspirant composition for topical application to the human skin comprising a solid particulate antiperspirant active suspended in a cosmetic base, characterised in that the antiperspirant active comprises a blend of relatively small particles with a volume average particle size in the range 0.5 to 8&mgr;m and relatively large particles having a volume average particle size in the range greater than 12 to less than 50&mgr;m.

Description

COSMETIC COMPOSITION ANT I TRANSP I RANTE DESCRIPTION OF THE INVENTION This invention relates to cosmetic compositions in the form of a bar. In particular, it relates to compositions for topical application to human skin which are compositions an t i t r ansp an t e s. Such bar compositions can typically be used in conjunction with a bar holder for convenience of use. The anti-antiresorptive bars are known for the type of emulsion, wherein for example an antiperspirant active material is dissolved in an aqueous internal phase of an emulsion. Alternatively, it is known by the antiperspirant active, which is typically a metal salt, such as an ammonium or zirconium salt, to be suspended in small particles in a different solid cosmetic base. Such suspension bars are typically based on a gelling agent such as a wax material sometimes in combination with a carrier fluid that is typically an oil material such as a silicone fluid. A problem associated with the suspension bar is that which is desired to improve the sensory properties of the product, such as the feeling of the product on the skin during application. In such suspension bars, the average particle size volume of the suspended antiperspirant active material is typically in the range of 0.5 to about 8 μ. It has been found that the incorporation of particles of the largest antiperspirant active material (ie having an average volume of particle size larger than about 12 μm and smaller than about 50 μm and typically in the region of 15 to 25 μm) in such suspension bars it contributes positively to the sensory properties of the cosmetic bar in the application. In particular, the improved "sliding" of the bar on the skin has been observed. In addition it has been found that by using a mixture of relatively fine particle size (ie an average volume of particle size from 0.5 to 8 μm) and an asset of relatively large particle size, (typically of an average volume) of particle size greater than 12 μm and less than 50 μm, and notably of an average particle size volume of 15 to 25 μm) in such a "topical" composition provides a sensory benefit compared to a bar containing only the active size of relatively fine particle In particular, it has been found that when such a combination of larger and smaller average volume particle size active assets is used, a settlement of the larger particle size material during manufacturing of the product is prevented, by therefore avoids an uneven distribution of the antiperspirant active in the product Formulations of antiperspirant stick containing an active Antiperspirant particles are described in USP 4822603 and WO 94/24995. However, no specification describes a bimodal distribution of antiperspirant activity or the manner in which a bimodal distribution can provide a sensory benefit while improving the problems of the particles. Thus, according to the invention, there is provided * a suspension antiperspirant composition for topical application to human skin comprising an antiperspirant active in solid particles suspended in a cosmetic base, characterized in that the antiperspirant active comprises relatively small particles with a average volume of particle size in the range of 0.5 to 8 μm and relatively large particles that have an average particle size volume in the range of 12 to 50 μm Preferably, the relatively large to relatively small particle percentage in the composition is in the region of 5: 1 to 1: 5 by weight, more preferably in the region of 3: 1 to 1: 3 by weight. Conveniently, the cosmetic base material of the composition may be based on a mixture of a gelling agent with a carrier fluid, for example, a long chain fatty alcohol and a volatile silicone, although the cosmetic base can be any known cosmetic base composition. Where the cosmetic base is a mixture of a long chain fatty alcohol and a volatile silicone, the fatty alcohol may for example be fatty alcohol from Cs to C22 / - such as cetyl alcohol, stearyl alcohol, myristyl alcohol, lauryl alcohol, behenyl alcohol and mixtures thereof. Typically, such long chain fatty alcohols may be present in the composition at a level of 5 to 25 1 by weight.

The volatile silicones useful in such solid stick compositions can be either cyclic or linear, cyclic or linear, containing 3 to 9, preferably 4 to 5, silicone atoms. Suitable materials include silicones presented by Dow Corning Corporation, for example, Dow Corning 344, 345 and 200, Union Carbide, including silicone 7207 and Silicone 7158, and Stauffer Chemical, such as SWS-03314. Other suitable components of the composition include waxes, such. as, beaver wax, fatty acids, silicone waxes and glycerol monostearate, with wax levels typically being in the region of 0.5 to 25% by weight. Preferably, the composition according to the invention is essentially anhydrous - that is, it comprises less than about 1% by weight of water. The antiperspirant active in the composition can be any known antiperspirant active provided suspended in the composition but can in particular comprise a metal salt, based on aluminum and / or zirconium. The total amount of antiperspirant active material typically present in the composition is at a level of at least 10% by weight or more, to provide an antiperspirant benefit. Typically, 'the composition will contain no more than 26% by total weight of active' antiperspirant. For additional guidance regarding antiperspirant metal assets, an unrestricted list of anti-thiamine metal salts is provided by the FDA in "Altiperspirant drug products for over the counter human use, a tentative final monograph", Federal Register 47: 36592 (1982). The average particle size volume of the smallest particle material is in the region from Q.5 to 8 μm, and is preferably in the region from 3 to 6 μ. The average particle size volume of the material of the largest particle size is the region of greater than 12 to less than 50μm, and may preferably be in the region of 12 to 35μm, more preferably in the region of 15 to 25μm, more preferably about 18 μ. It was found that around this average particle size volume of optimal sensory benefits were achieved, and that the tendency of the largest particle size material to test established is minimized.

Alternatively, the asset of relatively large particle size can be characterized by the measurement of the particle size distribution and the derivation of a peak value of particle size, and mapping a range of particle size on either side of the peak value on the which particle population is at least half the peak particle size, wherein the lowest of these so-called "average peak height" particle size values is greater than 10 μm. It was also found that the relatively small and relatively large particle size average active volume mixtures in the compositions according to the invention often produce more than one peak above 2 μm (i.e., two distinct peaks are visible). ) when it is seen as a distribution of the number of particles against the particle size that uses laser scattering techniques. The average volume of particle size of active agents used in the compositions according to the invention is determined by laser scattering techniques using a light scattering instrument such as a Malvern MasterSizer. A suitable technique used refers to "The Basic Principles of Particle Size Analysis" by Dr. Alan Rawlw of Malvern Instruments Ltd. Spring South, Marvern, Wo r ce s t er shir a, England. Annotation materials of different sizes of average volume particles are available as proprietary materials, for example AZG 7167 (eg Summit, which has an average particle size volume of about 5μm), AZG 6313 (eg Summit, which has an average particle size volume of about 18 μm), and Westchlor ZR30B DM HBD (for example, Westwood which has an average volume of particle size of about μm). In a preferred embodiment of the invention, the composition additionally comprises a masking oil, which can typically be presented at a level of from 3 to 40% by weight of the composition. Suitable masked oils include, for example, polydecene, polybutene, PPG-14 butyl ether, non-volatile silicones, isopropyl myristate, isopropyl palmitate, C 1 -C 15 alkylbenzene, and mineral oils. The antiperspirant composition according to the invention it can comprise other ingredients that depend on the properties required in the finished product. Examples of other ingredients that may optionally be present in a cosmetic base in a composition according to the invention include: cosmetically acceptable carriers, such as straight chain and lower alcohols. branched, P. or r example ethanol, isopropanol, or isobutanol; -non-volatile silicates; -compounds of antimicrobial soda, which include desoperfumes and compounds that may also act as anti-microbial agents, such as unsaturated fatty acids or other antimicrobial agents, for example, or DP300, former Ciba Geigy; -improving skin feel, such as talcum powder and finely divided polyethylene, an example of which is Acumist B18; humectants, such as polyols, for example glycerols; -elements; -blockers; -'per fu is; -preservatives and antioxidants; - beneficial agents for the skin, such as all ant or ina; -colors; skin-cooling agents, such as menthol and menthol derivatives; -other attached cosmetics conventionally used in antiperspirant bar products. The remainder of the composition (may be from 76 to 90% by weight) may typically comprise any of the above components in the cosmetic base. The compositions according to the invention can typically be prepared by heating the carrier fluid (for example volatile silicone) and any gelling agent such as waxes to 80% ° C, and stirring the melted mixture. The powder components of the composition are then added (for example, active materials ant i tr ansp r an t, talc) and carefully mixed. The composition is then cooled to 65 ° C, and any perfume is added. The composition is then cooled to 58 ° C, and poured into the bar barrels and then further cooled to form a solid stick.

The invention will now be further described, by way of example only.

Compositions The following compositions are prepared according to the method described in the foregoing, and are in accordance with the invention: Except as specifically mentioned, all quantities are percentages by weight of the composition. (1) - the average particle size volume of about 5 μm for example Summit (2) - average volume of particle size of about 18 μm, for example Summit (3) - Lorol C18 Deo, for example Henkel ( 4) - Castorwax MP80, for example Caschem (5) - Estol E04DS3724, for example Unichema (6) - Suprafino tale, for example Cyprus I ndus tries (7) - DC 345, for example Dow Corning Test The bars according to the above compositions, together with a standard bar antiperspirant (in which total of the active anti-ansp anne has an average volume of particle size of less than 8μm) and one in which the total of the active was of the size of the largest particles (in the region 16-20μm) were evaluated for the distribution of the antiticide active in the bar, and also the panel tested in volunteers to smooth an application.

The method of determining the concentration of the anti-stress active in different parts of the bar is by means of conductivity measurements, which involve the immersion of a given weight of a product from a part of the bar (ie, upper, medium or lower) in a controlled temperature water bath, and measure conductivity. An increased level of conductivity indicates a higher concentration of ions in the solution, which in turn refers to the level of the antiperspirant active material present in that bar segment. The conductivity measurements carried out in the bar containing only an asset with an average volume larger than the particle size (ie 16-20μm) that indicated that a degree of establishment of the asset occurred at the time of taking it for the bar to solidify, and therefore there was a deficiency of active anti-perspirant in one part of the bar. However, conductivity measurements indicate that this sedimentation problem was alleviated with compositions 1-3 containing larger and smaller particle size mixtures of the active materials.

In addition, as indicated by the following average panel score, the compositions comprise mixtures of antiperspirant active materials of different average particle size volumes demonstrating, improved smoothness in one application over a standard bar containing only fine active material (less than 8 μm), and a similar degree of smoothness when the bar contains only 16-20 μm act io.

"Standard" softness bar (0.5-8μm active) 43 Bar containing 16-2fJμm active 62 Composition 1 59 Composition 2 63 Composition 3 72 This analysis was carried out using the established descriptive sensory analysis methodology (Stone, H & Sidel, JL; Sensory Evaluation Practices, Academic Press, Inc. 1985) in which sensory properties are evaluated using a panel of specialized judges to evaluate a range of well-defined sensory attributes. An O score indicates minimal softness while a score of 100 indicates maximum softness.

Claims (8)

1. An anticoagulant composition intended for suspension for topical application to human skin comprising an antiperspirant active in solid particles suspended in a cosmetic base, characterized in that the antiperspirant active comprises a mixture of relatively small particles with an average volume of particle size in the range of 0.5 to 8 μm and relatively large particles having an average volume of particle size in the range greater than 12 at less than 5 Q μm.

2. The suspension composition in suspension according to claim 1, wherein the antiperspirant active having an average volume of particle size in the range of 12 to 50 μm has a particle size of 12 to 35 μm.

3. The antiperspirant suspension composition according to claim 1, wherein the antiperspirant active having an average volume of particle size in the range of 12 to 50 μm has a particle size of 15 to 25 μm.

4. The antiperspirant composition in suspension according to any of the preceding indications, wherein the weight ratio of the antiperspirant active having a smaller average volume of the particle size to the antiperspirant active having a larger average volume of the particle size in the composition is in the region of 5: 1 to 1: 5 by weight.

5. The suspension antiperspirant composition according to claim 4, wherein the percentage is in the region of 3: 1 to 1: 3 therefore.

6. The antiperspirant suspension composition according to any of the preceding claims, wherein the antiperspirant active comprises 10-26% by weight of the composition.

7. The antiperspirant suspension composition according to any of the preceding claims, which additionally comprises a coating oil

8. The suspension antiperspirant composition according to any of the preceding claims wherein the composition is essentially anhydride.