A comparative in vitro study of transdermal absorption of antiemetics

Transdermal absorption of a series of antiemetics (alizapride, bromopride, clebopride, domperidone, metoclopramide, metopimazine, and scopolamine) was studied in vitro with the skin of hairless rats as the membrane. The aim of the study was to determine the permeation parameters [transdermal permeability rate constant (Kp), lag time, and flux] as a measure of the intrinsic permeability of these drugs across the skin, with a view to predicting their potential therapeutic formulation in Transdermal Therapeutic Systems. A linear correlation was established between the log Kp values corresponding to the antiemetics studied and their melting point (r = 0.8120, p < 0.05). The logarithm of Kp for the antiemetics studied can be predicted from the logarithm of the intrinsic partition coefficient (n-octanol-water) by a parabolic function (r = 0.9284, p < 0.01). Bromopride showed the shortest lag time (19.73 h), whereas clebopride was the most suitable drug as a candidate for formulation in transdermal delivery systems.