Stability indicating RP-HPLC method for simultaneous estimation of darunavir and ritonavir in pure drug and tablet dosage form

Abstract

This project presents a sensitive, rapid, precise and accurate stability indicating RP-HPLC technique for the estimation of two antiviral drug combination, ritonavir and darunavir in bulk and tablet form. Ritonavir and darunavir are extracted with mobile phase from the tablets. Analysis was done on a C8 YMC column by detection with photodiode array detector. Mobile phase composition with 0.1M potassium dihydrogen phosphate and methanol in proportion of 65:35 v/v is employed for analysis. The limits of quantification were 0.160 µg/ml and 2.359 µg/ml for ritonavir and darunavir, respectively.The limits of detection for ritonavir and darunavir are 0.048 µg/ml and 0.708 µg/ml, respectively. The precision (ritonavir – 0.142% RSD and darunavir – 0.116% RSD ) and accuracy (ritonavir – 99.77% to 99.94% recovery and darunavir – 99.39% to 99.65% recovery) remained within standard limits while validation study. Ritonavir and darunavir were degraded applying acid, alkali, oxidative, neutral, thermal and photo degradation conditions. While degradation study, no substantial interfering peaks are seen in chromatograms of all tested degradation conditions at the retention time of ritonavir and darunavir. Finally it was concluded that the quantitative RP-HPLC method developed and validated can be utilized in routine analysis of ritonavir and darunavir in tablets and for stability related studies of ritonavir and darunavir in tablets.