Influence of Vehicle Composition on the Penetration of Indomethacin through Guinea-Pig Skin

In order to investigate the process of percutaneous absorption of indomethacin (IND) from aqueous ethanol solution, the flux of IND was determined under various conditions by using a specially designed diffusion cell which was attached to the back of a guinea-pig. It was found that the flux of IND was governed by the initial concentration of IND, pH, the amount of ethanol in the vehicle and the amount of additive ester : the flux increased with increase in the concentrations of IND and added ester, but decreased with increase in pH and the amount of ethanol. The interactions of the components of the vehicle with IND and the skin appeared to influence the process of the percutaneous absorption of IND very strongly.