TRANSDERMAL PROPERTIES OF TIMOLOL AND FACTORS AFFECTING ITS PERMEABILITY IN VITRO

V-C horizontal diffusion cell has bee nsed to carry out the initialstudy of timolol across intact and stripped hairless mouse skin and human cadaver skin.Also, we have systematically studied the effect of some factors such as hydration time,me-dium pH value as well as various transdermal enhancers on the Permeability of timolol invitro. We investigated the determination method of timolol by RP-HPLC using YWG-C18 column with water-acetonitrile-triethylamine (87: 13: 1) as the mobile phase.The results indicated the feasibility of transdermal absorption of timolol. The Perme-abilities of timolol raised significantly With properly extending of hydration time, increa-sing of medium pH and with presence of various kinds of transdermal enhancers. With10% propylene glycol and 1% azone were used conjunctly, they showed obviouslysynergistic effects. All these studies contributed theoratically and practically to the furtherdevelopment and utilization of timolol in the form of transdermal patch.