T h e percutaneous toxicity of three salts of pyridinethione i n water and dimethylsulfoxide is described. Sodium and zinc pyridinethione penetrated the skin of rabbits when applied in a dimethylsulfoxide vehicle and caused hind quarter paralysis. Cadmium pyridinethione did not penetrate the skin in amounts comparable to the other two salts regardless of the vehicle. HE SALTS of 1-hydroxypyridine-2-thiol have been T shown to be effective antifungal and antibacterial agents. The zinc salt (ZnPT) is in current use as an antidandruff agent. Snyder et al. (1) have reported on the toxicity of ZnPT in a shampoo base and found no percutaneous effects in rabbits. The sodium salt (NaPT) was shown to penetrate the skin of rabbits causing hind quarter paralysis. Winek and Buehler (2) reported on the intravenous toxicity of the pyridinethiones. Following the recent usage of dimethylsulfoxide (DMSO) by Jacob et al. (3, 4) and others as a topical drug for arthritic conditions, considerable work on the enhancement of percutaneous absorption of various compounds by DMSO has been reported. Kligman (5) studied the percutaneous absorption of a large number of different types of compounds in different concentrations of DMSO and other solvents. With most, he found absorption greatly enhanced over other solvents.
The present study concerns the effects of the sodium, zinc, and cadmium salts of pyridinethione in a DMSO vehicle after application to the skin of rabbits.