Abstract
Permeabilities of acetaminophen, bucolome (5-n-butyl-1-cyclohexyl-2, 4, 6-trioxo-perhydropyrimidine), salicylic acid, aminopyrine, sulfamethizole, sulfisomidine, and p-aminobenzoic acid through a collagen membrane were measured at different pH values. The effect of pH of the media on permeation of acetaminophen, an unionizable drug in the pH range studied, was minor. Drugs in molecular form permeated faster than those in ionic form. Amphoteric drugs in cationic form permeated slower than those in corresponding anionic form. Little effect of charges of the drug molecules was observed on drug permeation through a cellophane membrane.