HPLC analysis of generic antiretroviral drugs purchased in Rwanda

A reversed phase HPLC method using photo diode array detection for the simultaneous quantification of lamivudine, stavudine, nevirapine, zidovudine, methyl paraben and propyl paraben in solid and liquid drug formulations was developed and validated. The separation was achieved using a Waters Symmetry C8 column, using a mobile phase gradient comprising 50 mM NaH2PO4 (pH 3.8) and acetonitrile (95:5 to 45:55, v/v) and a flow gradient (0.5 to 1.0 ml/min). The limits of detection and quantification were below 19 ng/ml and 55 ng/ml respectively. The intra- and inter-day assay precisions were within 4.4% relative standard deviations. The developed method was applied to 12 different generic antiretroviral medications, consisting of tablets, capsules and solutions, produced by two Indian manufacturers and purchased by the Central Agency of Essential Drug Procurement of Rwanda for the ESTHER project in Rwanda. The average content of the antiretroviral agent(s) compared to the labeled amount(s) was 101.4%. Methyl paraben and propyl paraben, added to solutions as preservatives, were within the FDA recommended limits.