Chemometric Optimization for Simultaneous Determination of Anti-retroviral Drugs by RP-HPLC

This work deals with multiple response simultaneous optimization using the Derringer’s desirability function for the development of a reversed phase HPLC method for the simultaneous determination of lamivudine, tenofovir and efavirenz in commercial pharmaceutical preparations. Twenty experiments, taking the capacity factor of the first peak, resolution between the secondand third peaks and the retention time of the thirdpeak as the responses with three important variables as organic phase composition, buffer molarity, and flow rate, were used to design mathematical models. The experimental responses were fitted into a second order polynomial and the three responses were simultaneously optimized to predict the optimum conditions for the effective separation of thestudied compounds. The optimum assay conditions were: methanol–triethylamine buffer (pH 3.0; 15.3 mM) (35:65%v/v) as the mobile phase and at a flow rate of 1.19 ml/min. While using this optimum condition, a baseline separation with a minimum resolution of 2.0 and a run time of less than 6 min wasachieved. The method showed a good agreement between the experimental data and predictive value throughout the studied parameter space. The optimized assay condition was validated according to the International Conference on Harmonization guidelines to confirm specificity, linearity, accuracy, and precision.