Anhydrous antiperspirant compositions

Abstract

Anhydrous antiperspirant stick or soft solid composition comprising an antiperspirant active system, thickening agent, and non-aqueous carrier oil, characterized in that the particulate antiperspirant active system comprises an aluminium sesequichlorohydrate of formula Al.sub.2OH.sub.4.4Cl.sub.1.6 to Al.sub.2OH.sub.4.9Cl.sub.1.1 activated with a water soluble calcium salt.

Claims

1. An anhydrous antiperspirant stick or soft solid composition comprising an antiperspirant active system, thickening agent, and non-aqueous carrier oil, characterised in that the particulate antiperspirant active system is composed of a water soluble calcium salt, an amino acid and an aluminium sesquichlorohydrate of formula Al.sub.2(OH).sub.4.7Cl.sub.1.3 to Al.sub.2(OH).sub.4.9Cl.sub.1.1 heat activated with a water soluble calcium salt and an amino acid, wherein the aluminium sesquichlorohydrate in the antiperspirant active system has a molar ratio of calcium to aluminium of at least 1:20 and a molar ratio of amino acid to aluminium of at least 1:10 and wherein the particulate antiperspirant active system has a mean particle size (D50) of from 2 to 30 microns, wherein the antiperspirant active system is present in a concentration of 17.5% to 25%, by weight of the composition, and wherein the amino acid is glycine.

2. The composition according to claim 1, wherein the aluminium sesquichlorohydrate in the antiperspirant active system has a Band III content of at least 40%.

3. The composition according to claim 1, wherein the aluminium sesquichlorohydrate in the antiperspirant active system has a molar ratio of calcium to aluminium of at least 1:15 and the molar ratio of amino acid to aluminium of at least 1:4.

4. The composition according to claim 1, wherein the water soluble calcium salt is calcium chloride.

5. The composition according to claim 1, wherein the aluminium sesquichlorohydrate in the particulate antiperspirant active system has a Band III to Band II ratio of 5:1 or greater.

6. The composition according to claim 1 wherein the particulate antiperspirant active system has a mean particle size (D50) of from 2 to 10 microns.

7. The composition according to claim 1 wherein the composition is in the form of an anhydrous antiperspirant stick.

8. A method of manufacture of an antiperspirant composition according to claim 1, wherein a solution of aluminium sesquichlorohydrate of formula Al.sub.2(OH).sub.4.7Cl.sub.1.3 to Al.sub.2(OH).sub.4.9Cl.sub.1.1 is heated with a water soluble calcium salt to achieve a Band III content of at least 40% before being spray dried to give a powder which is subsequently formulated with thickening agent and non-aqueous carrier oil to give a composition having a penetration force value of at least 500 gram-force, wherein both calcium and amino acid are present and the molar ratio of calcium to aluminium is at least 1:20 and the molar ratio of amino acid to aluminium is at least 1:10.

9. The method according to claim 8, wherein the solution of aluminium sesquichlorohydrate of formula Al.sub.2(OH).sub.4.7Cl.sub.1.3 to Al.sub.2(OH).sub.4.9Cl.sub.1.1 is heated with a water soluble calcium salt and an amino acid to achieve a Band III content of at least 60% before it is spray dried.

10. The method according to claim 8, wherein the water soluble calcium salt is calcium chloride.

Description

EXAMPLES

(1) In the following examples, all percentages are by weight, unless otherwise indicated.

(2) The ASCH used was approximately 80% anhydrous ASCH solids (and 20% water) and was obtained from Summit as Reach 301.

(3) The ASCH used was activated with calcium chloride and glycine and treated as follows.

(4) 30 parts of Reach 301 powder, 4.0 parts calcium chloride dihydrate and 9.4 parts glycine were combined with 56.6 parts water. 60 L of this solution was heated at 85 C. and then maintained at this temperature for 5 hours in a corrosion resistant 70 L vessel.

(5) The resulting solution was spray-dried using a large scale spray dryer (inlet temperature 290+/5, outlet temperature 117+/2, rotary atomisation).

(6) The particulate AASCH obtained from the above process had a mean (D50) particle size of 27 microns, a Band III content of 66%, and a ratio of Band II to Band III of 1:7.13. It comprised 19.3% Al, 2.8% Ca, and 26.0% glycine. This powder was jet milled to give a mean (D50) particle size of 4.3 microns. The milling resulted in an increase in the water content of the powder of from 3.3% to 7.5%.

(7) The powder resulting from the above processes was formulated with the other components indicated in Table 1 by methods known in the art to give Examples 1 to 4, varying only in the amount of AASCH employed.

(8) Comparative Example A was also prepared by methods known in art, using a commercially available activated zirconium aluminium glycinate (AZAG) antiperspirant active (Reach 908, ex Summit) at 25%, i.e. equivalent to the AASCH level used in Example 2.

(9) TABLE-US-00001 TABLE 1 Examples 1 to 4 and Comparative Example A Component Example Chemical name Trade name 1 2 3 4 A AASCH.sup.1 30.0 25.0 17.5 10.0 AZAG Reach 908 25.0 Cyclomethicone DC 245 24.75 29.75 37.25 44.75 29.75 C.sub.12-15 alkyl Finsolv TN 13.75 13.75 13.75 13.75 13.75 benzoate PPG-14 butyl Fluid AP 8.0 8.0 8.0 8.0 8.0 ether Stearyl alcohol Lanette C18 Deo. 18.0 18.0 18.0 18.0 18.0 Castor wax MP80 3.5 3.5 3.5 3.5 3.5 Polyethylene wax Performalene 400 1.0 1.0 1.0 1.0 1.0 Fragrance Parfum 1.0 1.0 1.0 1.0 1.0 SWR (%) vs. A +31 +27 +14 7 0 .sup.1Prepared as described above.

(10) Sweat Weight Reduction (SWR) results were obtained for each Example in direct comparison with a standard AZAG stick product (Comparative Example A) using a test panel of 30 female volunteers. Test operators applied ca. 0.3 g of Example 1, 2, 3, or 4 to one axilla and Comparative Example A (ca 0.3 g) to the other axilla of each panelist. This was done once each day for three days for each comparison. After the third application, panelists were requested not to wash under their arms for the following 24 hours.

(11) 24 hours after the third and final product application, the panelists were induced to sweat in a hot-room at 40 C. (2 C.) and 40% (5%) relative humidity, for 40 minutes. After this period, the panelists left the hot-room and their axillae were carefully wiped dry. Pre-weighed cotton pads were then applied to each axilla of each panelist and the panelists re-entered the hot-room for a further 20 minutes. Following this period, the pads were removed and re-weighed, enabling the weight of sweat generated to be calculated.

(12) The SWR for each panelist was calculated as a percentage (% SWR) and the mean % SWR was calculated according to the method described by Murphy and Levine in Analysis of Antiperspirant Efficacy Results, J. Soc. Cosmetic Chemists, 1991 (May), 42, 167-197.

(13) From the results in Table 1 it can be seen that the stick with 25% AASCH (Example 2) gave a SWR reduction that was 27% greater than the standard AZAG stick product, a remarkable result. Also, a stick with only 17.5% AASCH (Example 3) gave a SWR reduction that was marginally better the standard AZAG stick product.

(14) The soft solid compositions detailed in Table 2 (Examples 5 to 9) may be prepared using the same AASCH as used for Examples 1 to 4, using methods known in the art.

(15) TABLE-US-00002 TABLE 2 Examples 5 to 9 Example Chemical name 5 6 7 8 9 AASCH 28.0 26.3 25.0 20.0 20.0 Cyclopentasiloxane To 100 To 100 To 100 To 100 To 100 Silicone elastomer.sup.1 4.0 4.0 4.0 4.0 4.0 Fumed silica 1.0 1.0 1.0 1.0 1.0 Dimethicone 5.0 5.0 10.0 (350 mPa .Math. s) PPG-14 butyl ether 10.0 5.0 C.sub.12-15 alkyl benzoate 10.0 5.0 Sunflower seed oil 0.5 0.5 0.5 0.5 0.5 Microcrystalline wax 3.5 3.5 3.5 3.5 3.5 (MP 80-87 C.) Paraffin wax 3.5 3.5 3.5 3.5 3.5 (MP 60-62 C.) Fragrance 0.8 0.8 0.8 0.8 0.8 .sup.1DC9040, ex Dow Dorning. 70-90% Cyclopentasiloxane.