Formulation Development and Characterization of Darunavir and Ritonavir Immediate Release Tablets using Quality by Design approach

Darunavir is a nonpeptidic inhibitor of protease and is primarily metabolized by cytochrome P450 3A (CYP3A) isoenzymes. It is usually Coad ministered with low-dose ritonavir (Darunavir/r). Ritonavir is an inhibitor of CYP3A isoenzymes and pharmacologically enhances Darunavir which leads to increased plasma concentrations of darunavir and allows for daily lower dose. Here, we have developed combination IR formulation of Darunavir and Ritonavir and evaluated. In vitro drug release of all formulations was carried out in dissolution medium 900ml of pH 3.0 0.05 M Sodium Phosphate Buffer + 2% Tween 20 for 75 Min USP II apparatus (paddle). The results shown that, all the formulations of matrix tablets shown the good release of drug from trialed formulations however all formulations were not releasing the drug in enough amount. In matrix tablets F8, the release of drug shows 99%. So, the formulation F8 has been considered as suitable for the immediate release of Darunavir and Ritonavir. Tablets were also evaluated for physic chemical properties, dissolution studies and though Quality by Design (QbD) method.