[Studies for analyzing restricted ingredients such as phenylbenzoimidazole sulfonic acid].

Phenylbenzoimidazol sulfonic acid (PBS) is a kind of sunscreens in cosmetics and is nominated as the restricted ingredients in cosmetics in Japanese Pharmaceutical Affairs Act. So the analytical method for PBS was investigated by HPLC. 1.

[Studies for analyzing restricted ingredients such as sodium benzoate].

Sodium benzoate is a kind of preservatives in cosmetics and is nominated as the restricted ingredients in cosmetics in Japanese Pharmaceutical Affairs Act. So the analytical method for sodium benzoate was investigated by HPLC. After adding 5 ml of tetrahydrofuran to 0.

[Studies for analyzing the restricted ingredients such as 2-(2'-hydroxy-5'-methylphenyl)-benzotriazole].

2-(2'-hydroxy-5'-methylphenyl)-benzotriazole (HMB) is nominated as the restricted ingredients in cosmetics in Japanese Pharmaceutical Affairs Act. So the analytical method for HMB was investigated by HPLC. After dissolving HMB in cream or oil with tetrahydrofuran and making the constant volume with methanol, the test solution was prepared.