Analytical Method Development and Validation for the Simultaneous Estimation of Darunavir and Cobicistat by RP- HPLC Method

Dr. K. Nageswara Rao^1*, Raghava Doonaboyina², T. Naga Sirisha Devi^3
1Professor and Head, Department of Pharmaceutical Analysis, K.G.R.L College of Pharmacy, KGRL Road, Bhimavaram, West Godavari, Andhra Pradesh, India.
²Associate Professor and Head, Department of Pharmaceutical Chemistry, K.G.R.L College of Pharmacy, KGRL Road, Bhimavaram, West Godavari, Andhra Pradesh, India.
³K.G.R.L College of Pharmacy, KGRL Road, Bhimavaram, West Godavari, Andhra Pradesh, India.

A B S T R A C T
A new method was established for simultaneous estimation of Cobicistat and Darunavir by RP-HPLC method.  The chromatographic conditions were successfully developed for the separation of Cobicistat and Darunavir by using XterraC185µm (4.6*250mm) column, flow rate was1ml/min, mobile phase ratio was Phosphate buffer (0.05M) pH4.6: ACN (55:45%v/v) (pH was adjusted with orthophosphoricacid), detection wave length was 255nm. The instrument used was WATERS HPLC Auto Sampler, Separation module 2695, PDA Detector 996, Empower-softwareversion-2.Theanalyticalmethodwas validated according to ICH guidelines (ICH, Q2(R1)). The linearity study for Cobicistat and Darunavir was found  in  concentration  range   of  1μg-5μg  and  100μg-500μg   and correlation coefficient(r2)was found to be 0.999and 0.999,%mean recovery was found to be 100% and 100.5%, %RSD for repeatability was.0.2 and 0.4, %RSD for intermediate precision was 0.5and 0.1 respectively.
Keywords: Cobicistat Darunavir, RP-HPLC, Phosphate buffer, ACN