Method Development and Validation of Stability Indicating RP-HPLC Method for Simultaneous Estimation of Atazanavir and Ritonavir in Bulk and Its Pharmaceutical Formulations

A new rapid, precise and sensitive reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the estimation of Atazanavir and Ritonavir simultaneously in combined dosage form. The two components Atazanavir and Ritonavir were well resolved on an isocratic method, C18 column, utilizing a mobile phase composition of acetonitrile: 0.02M ammonium acetate buffer (40:60), v/v, pH 4.0) at a flow rate of 1.0 mL/min with UV detection at 205 nm. The retention time of Atazanavir and Ritonavir were 2.8 min and 5.7 min respectively. The developed method was validated for specificity, linearity, precision, accuracy, limit of detection (LOD), limit of quantification (LOQ) and robustness as per ICH guidelines. Linearity for Atazanavir and Ritonavir were found in the range of 18.0-42.0 µg/ml and 5.0-14.0 µg/ml, respectively. The percentage recoveries for Atazanavir and Ritonavir ranged from 98.9-101.0 % and 98.2-100.1 %, respectively. The proposed method could be used for routine analysis of Atazanavir and Ritonavir in their combined dosage forms.