HPTLC-densitometric method development and validation for simultaneous determination of lamivudine, nevirapine and zidovudine in fixed dose combinations

Abstract

In this study an HPTLC-densitometric method was developed for the simultaneous determination of lamivudine, nevirapine and zidovudine in pharmaceutical dosage forms which are used widely as first line HIV/AIDS treatment. Chromatographic separation of the drugs was performed on precoated silica gel 60F254 (0.2 mm thickness) plates using n-hexane: chloroform: methanol (1:7:2, v/v) as a mobile phase. A TLC scanner set at 275 nm was used for the direct evaluation of the chromatogram in reflectance-absorbance mode. The three drugs were satisfactorily resolved with Rf values of 0.22 ±0.03, 0.55 ±?0.03 and 0.73 ±?0.03 for lamivudine, zidovudine and nevirapine, respectively. Calibration curves were polynomial in the range 100-1300 ng/band for both lamivudine and nevirapine, and from 100-1700 ng/band for zidovudine. Correlation coefficients (r) values were 0.9999 for lamivudine and 0.9998 for nevirapine and zidovudine. A low relative standard deviation (<2%) was found for both precision and robustness study showing that the proposed method was precise and robust. The method had an accuracy of 98.93%, 99.45% and 99.21%; and percentage assay of 99.91%, 98.72% and 99.34% for lamivudine, nevirapine and zidovudine, respectively. Method had the potential to determine these drugs simultaneously from dosage forms without any interference.