Patent ID: 7087220

Claim:
A method of making an antiperspirant liquid composition having improved efficacy and a pH value of at least 3.5 when dissolved as 15% by weight aqueous solution and wherein the composition comprises an antiperspirant active selected from (i) basic aluminum salts having the formula Al 2 (OH) 6-a X a wherein X is Cl, Br, I or NO 3 , a is from about 1.1 to about 6, at a concentration of about 20% to about 40% by weight of anhydrous solid and having an aluminum to anion mole ratio of about 1.0 to about 1.8 and (ii) aluminum-zirconium salts having an Al:Zr ratio of from about 2:1 to about 10:1 that are obtained by adding to the salts of formula (i) a zirconium compound selected from those having the formula ZrO(OH) b X 2-b wherein b is a number from 0 to 1.2, and X is Cl, Br, I or NO 3 , the steps comprising: (1) treating the aqueous reaction mixture of said antiperspirant active with from about 0.1% to about 2% by weight of an additive selected from the group consisting of strongly alkaline water insoluble calcium and strontium compounds and mixtures thereof, and (2) mixing and reacting said mixture, wherein said additive is activated by contact with said antiperspirant active, until a stable solution with respect to HPLC Band III and Band II area ratio of at least 0.5 is obtained.