Abstract

An assay method for the evaluation of topically applied anticholinergic agents was described. Evaluation of mydriatic agents in mice was reliable, convenient, and simple, readily permitting the use of enough animals for statistical analysis of the data. The potency of topically applied scopolamine hydrobromide and atropine sulfate and their quaternary derivatives were evaluated by this method. The topically applied tertiary compounds were more potent than their quaternary analogs; the onset of their action was more rapid and their duration shorter. The potency of these compounds was influenced markedly by the vehicle. Their potency in three types of vehicles was compared: Hind-Goyan II buffer, aqueous solutions of the surface-active agents benzalkonium chloride and miranol, and distilled water. Drug activity was least in Hind-Goyan II buffer and was increased by the other vehicles. The quaternary derivatives were significantly more affected by the vehicle. No specific enhancing effect could be ascribed to the surface-active agents.