The surface activity and self-association of some beta-adrenoceptor blocking agents in aqueous solution

The surface activity at the air-solution interface of a series of beta-adrenoceptor blocking agents has been determined. The drugs investigated included, propranolol, sotalol, oxprenolol, labetolol, timolol, metoprolol and acebutolol. Correlation between surface activity and local anaesthetic potency of the drugs is examined. Light scattering measurements have indicated self-association of sotalol, oxprenolol, acebutolol and metoprolol in 0.5 mol kg-1 sodium chloride. Critical micelle concentrations and aggregation numbers are reported.