JOURNAL OF COSMETIC SCIENCE 106 Figure 7. Zeta potential and turbidity trend of AP-BSA mixtures which had largest amount of precipitate with pH change from 3 to 12. (A) Activated ACH-BSA, (B) ZAG-BSA, (C) Al13-BSA, (D) ZG-BSA. In all four samples, solutions were all transparent at pH = 3, precipitate was observed when pH was raised over 4, at pH between 5 and 6, the largest amount of precipitate was formed, the precipitate dissolved and mixture solution became clear as pH was over 7. It is well known that activated ACH provides much better performance than standard non-activated ACH in sweat inhibition clinical studies. In addition, studies have also shown that ASCH is more effi cacious than both activated and regular ACH (35). Com- paring the experimental results, ASCH shows the most effective neutralizing capability Table IV Precipitation pH Range of AP–BSA Mixture Solutions Samples Precipitation pH range activated ACH 5  pH  7 ZAG 5  pH  7 Al13 4  pH  6 ZG 5  pH  6

OPTIMAL ALUMINUM/ZIRCONIUM—PROTEIN INTERACTIONS 107 Figure 8. Prediction of AP effi cacy by zeta potential measurements. (A) Comparison of Al containing spe- cies, (B) comparison of Zr containing species, (C) comparison of Al polyoxocations.