| ABSTRACT The aim of the present study was to investigate the effect of donor pH on the transdermal permeability of the model drugs across rat skin and also to determine the major route of transport of the drugs. Weakly acidic drugs (partition coefficient) ibuprofen (3.6), aceclofenac (3.9), glipizide (1.9) and weakly basic drugs olanzapine (3.6), telmisartan (6.0), and sildenafil citrate (1.9) were selected for the study. The ex vivo permeation studies of these drugs at different donor pH (pH - 1.2, 4, 5, 6.8, 7.4, and 8) using Franz diffusion cell (area, 7.54 cm2) has shown a pH-dependent permeability. Among these drugs the weakly acidic drugs has shown higher permeation rates compared to the weakly basic drugs. The permeability coefficient and the... |
