Evaluation of Topical Bioavailability of Clotrimazole Using Dermato Pharmaco Kinetic Method

In this single-dose-one arm, open label two way parallel design, pharmacokinetic study of two marketed formulations of Clotrimazole using 12 healthy Indian male subjects the pharmacokinetic parameters of two marketed Clotrimazole topical formulations were compared . Marketed Clotrimazole topical formulations (A & B) were applied on the pre-marked forearms of the subjects as per the dosing schedule. Treatment sample B was used as a reference sample. Subjects received treatment A & treatment B on both the arms simultaneously, following open label two way parallel design. Skin Stratum Corneum samples were collected in sterile glass test tubes during the study period. The samples were collected predose and at 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, & 6.0 hours post-dose application. The Stratum Corneum samples were analysed for Clotrimazole concentrations only. Pharmacokinetic parameters of Clotrimazole were calculated as Cmax, tmax, AUC (0-t) and AUC (0-∞) Clotrimazole was estimated in Stratum Corneum using a validated Spectroscopic method. If the point estimate of the geometric mean ratio and the confidence intervals for the entire log transformed pharmacokinetic parameters [Cmax, AUC (0-t) and AUC (0-∞)] were entirely included in the range of 80-125%, then the treatments were claimed to be bio-equivalent.