Zinc pyrithione has been proved an effective anti-dandruff agent. Several types of medicated shampoos contai ning this compound are sold and have been at the top share in the market in Japan.
Ultra fine particles of zinc pyrithione were developed to prevent their sedimentation in the shampoo formula. A stable dispersion in concentrated detergent solutions was achieved by treating the powder surface with polymers.
As compared to the commercial zinc pyrithion, the ultra fine particles of zinc pyrition in the shampoo formula showed a larger amount of and a higher rate of adsorption onto the human hair and the mouse skin.
But it showed the same percutaneous absorption into the rat skin as commercial zinc pyrithion.