¹Department of Chemistry, Acharya Nagarjuna University, Nagarjuna nagar, Guntur-522510, Andhra Pradesh, India
²Department of Applied Sciences and Humanities, Sasi Institute of Technology and Engineering, Tadepalligudem-534101, Andhra Pradesh, India DOI : 10.12991/mpj.20162036176 A simple, sensitive and precise stability indicating reverse phase high performance liquid chromatographic method has been developed and validated for the estimation of darunavir and cobicistat simultaneously in combined dosage form. The stationary phase used was Phenomenex C18 (150 x 4.6 mm, 5 μm particle size). The mobile phase used was a mixture of 0.1 M NaH2PO4 and methanol (70:30 v/v). Quantification was done with photodiode array detection at 260 nm over the concentration range of 80-240 μg/mL and 15-45 μg/mL for darunavir and cobicistat, respectively. The method had accuracy in the range of 100.11-100.31% for darunavir and 99.87-99.89% for cobicistat. Darunavir and cobicistat were also subjected to acid, base, oxidation, heat, photo and UV degradation. The degradation products obtained were well resolved from the darunavir and cobicistat with different retention times. Since the method can effectively separate the darunavir and cobicistat from its degradation products, it can be used as stabilityindicating method. Keywords : RP-HPLC, darunavir, cobicistat, stability indicating method