HPLC Estimation, Ex vivo Everted Sac Permeability and In Vivo Pharmacokinetic Studies of Darunavir.

Darunavir ethanolate (DRV) is an efficient protease inhibitor (PI) used in the treatment of human immunodeficiency virus (HIV) type-1 patients. An isocratic reversed-phase HPLC method was developed to monitor concentration of darunavir in in vitro intestinal fluid samples in everted sac absorption model in the presence of bioenhancers, viz., piperine, quercetin, naringenin. The method was validated and successfully applied to everted sac and pharmacokinetic studies in rats. The absorption profiles of DRV and apparent permeability coefficients were determined. The proposed method was found to be simple, rapid, robust and selective and was applied for continuous ex vivo monitoring of DRV in everted sac absorption studies. Of the three bioenhancers screened at different concentrations, piperine caused highest and significant 1.5-fold increase in apparent permeability of DRV across everted sac tissue. Further, co-administration of piperine significantly increased the maximum plasma concentration of DRV by 1.18-fold confirming the enhancement in its absorption.