HPTLC-densitometry method development and validation for simultaneous determination of abacavir, lamivudine and zidovudine in combined dosage form

A simple, accurate and precise HPTLC- densitometry method for the simultaneousdetermination of abacavir, lamivudine and zidovudine in pharmaceutical tablet has beendeveloped. Separation of tablet components was performed on aluminum backed HPTLC plates(silica gel 60 F254 20×20 cm with 0.2 mm thickness, Camag, Muttenz, Switzerland ) usingmethanol : chloroform : acetonitrile (4 : 8 : 3 v/v). Good sensitivity for all analytes was observedwith UV detection at 275 nm. The method was validated for linearity, accuracy, precision,specificity and robustness. The method allowed quantitation over the 200–1450 ng/band rangefor the three components. Both linear and second order polynomial relationships were studied.Second order polynomial fit was found to be more suitable and its residuals plot showed a muchbetter fitting than that of linear model, indicating good correlation and determinations (r =0.99995, 0.9998 and 0.9998 and r2 = 0.9999, 0.9997 and 0.9996 for 3-TC, ABC and AZT,respectively). The method has an accuracy of 99.35, 99.19 and 99.13 % for 3-TC, ABC and AZTrespectively. The method is robust and has the potential to determine these drug substancessimultaneously from the dosage forms.