Stability Indicating RP-HPLC Method for Simultaneous Estimation of Atazanavir and Cobicistat in Tablets

Aim: The aim of this study was to develop a stability indicating RP-HPLC method for simultaneous quantitative analysis of atazanavir and cobicistat in tablets.

Place and Duration of Study: At Rainbow Pharma Training Lab, Kukatapally, Hyderabad, India and Department of chemistry, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur, India in between October 2015 and February 2016.

Methodology: Atazanavir and cobicistat was eluted on the Inertsil C8, 150 mm x 4.6 mm, 5 µm analytical column with a mobile phase consisting of 0.1 M ammonium acetate and methanol (50:50 v/v), pumped at 1.2 mL/min flow rate. The column was maintained at 30°C and 10 μl of the solutions were injected. UV detection was performed at 234 nm. According to ICH guidelines, the method was validated.

Results: Under the optimized chromatographic conditions the retention times of atazanavir and cobicistat were 2.559 min and 3.576 min, respectively. Linearity was observed in the concentration range of 45-135 μg/mL for atazanavir and 22.5-67.5 μg/mL for cobicistat. The percent recovery and percent relative standard deviation for both the drugs were in the range of 99.311-100.342% and 0.290-0.401%, respectively. The results of forced degradation studies demonstrated the stability-indicating power of the method.

Conclusion: The proposed method was found to be appropriate for the quality control of atazanavir and cobicistat hydrochloride simultaneously in a bulk drug as well as in a pharmaceutical dosage forms.