Buccal absorption of phenol and p-chlorophenol in rats.

Abstract

In dental treatment some drugs containing phenol are used. Especially the‘compound iodine glycerin’, a remedy for oral mucous diseases, contains 0.43 to 0.53 % phenol. It is directly applied to the mucous membrane, although there are some opinions that phenol is contraindicative for the mucous membrane because of its systemic toxicity. In this experiment buccal absorption of phenol or p-chlorophenol was examined for a period of 120 minutes using the rat. The absorption increased with an increase in the fraction of the nonionized molecules existing in the solution in association with its pH. Reflecting the larger partition coefficient of p-chlorophenol, a much larger-amount of p-chlorophenol was absorbed from the buccal membrane than phenol. In both phenol and p-chlorophenol, a linear relationship was found between the logarithmic absorption and time. This means that their buccal absortion was a first order rate process. Moreover, the absorption rate was independent from the concentration of the solution, indicating that the buccal absorptions of phenol and p-chlorophenol was governed by a passive transfer mechanism.