Effects of breed, season, temperature, and solvents on the permeability of frozen and reconstituted cattle skin to levamisole.

In vitro measurements have been made of the permeability of frozen and reconstituted cattle skins to levamisole. Breeds used were Red Poll cross, Hereford/Shorthorn cross, Hereford/Santa Gatrudis cross (or Brahman), Friesian (or Friesian/Jersey cross), and Hereford cattle killed in early fall, early summer, or winter. Inter- and intrabreed differences in skin permeability were small, but skin permeability in summer and fall was appreciably greater than in winter. Increases in skin temperature also increased skin permeability. The solvent properties of the skin toward neutral molecules appeared to be similar to those of water, suggesting that skin is a relatively polar barrier.