Abstract: Morphological properties of flocculation in anti-dandruff shampoo,deposition of zinc pyrithione (ZPT) on human skin as well as combing performance of human hair were examined.Effect of various cationic polymers and particle size of silicones with respect to uniformity of ZPT covering and deposition were compared.The results showed that since the co-existence of small particle size silicone (SPS) in the system and over-flocculation of ZPT,most of cationic polymers are not suitable to be used in anti-dandruff shampoo;while surface modified cationic guar which helps to avoid formation of over-flocculation,can provide better conditioning performance and deliver high effective deposition of ZPT in SPS anti-dandruff shampoo.For anti-dandruff shampoo with large particle size silicone (LPS),the deposition effect of ZPT is direct proportional to the charge density and molecular weight of cationic polymer in the shampoo.

Key words: anti-dandruff shampoo, zinc pyrithione, silicone, cationic polymer, flocculation, deposition