Simultaneous determination of lamivudine, stavudine and nevirapine in antiretroviral fixed dose combinations by high performance liquid chromatography

An accurate, sensitive and specific reversed phase high performance liquid chromatographic method (RP-HPLC) for the simultaneous quantitative determination of the nucleoside reverse transcriptase inhibitors lamivudine, stavudine with the non-nucleoside reverse transcriptase inhibitor nevirapine in pharmaceutical fixed dose combinations is described. Chromatography was carried on C-18 column by gradient elution with two mobile phase components: mobile phase (A) comprising of 80% of 10 mM acetate buffer adjusted to pH 3.5 with glacial acetic acid and 20% methanol and mobile phase (B) comprising of 50% acetonitrile with 50% isopropyl alcohol. Mobile phase was pumped at a flow rate of 0.6 ml min−1 and UV detection was employed at 270 nm. The average retention times for lamivudine, stavudine and nevirapine were 5.9, 8.8 and 14.2 min, respectively. The calibration curves were linear (r > 0.999) in the range for each analyte. The method is accurate and precise with recoveries of lamivudine in the range of 98.7–100.4%, 99.2–100.6% for stavudine and 98.3–100.3% for nevirapine. No spectral or chromatographic interferences from the tablet excipients were found. This method which is rapid, simple and does not require any separation process has been successfully applied to the assay of commercial fixed dose formulations.