Validated specific HPTLC method for simultaneous estimation of zidovudine and lamivudine in its combined dosage form

Abstract

The objective of current study was to develop a validated, specific stability indicating normal-phase high performance thin layer chromatographic method for simultaneous estimation of zidovudine and lamivudine in their combined dosage form. The forced degradation studies were performed on pure zidovudine and lamivudine and also on their combined dosage form using acid, base, neutral, oxidation, thermal and photo stress to show the stability indicating capability of the developed method. Significant degradation products of zidovudine and lamivudine were observed in acidic, basic, neutral, oxidation and photo stress. No degradation products were obtained after thermal stress condition. The chromatographic method was optimized using samples generated in forced degradation studies. Good separation between the peaks corresponding to the zidovudine, lamivudine and degradation products from the analyte were achieved on silica gel 60F₂₅₄ TLC plate using toluene: ethyl acetate: methanol: formic acid 6.5:2.5:1.5:1.5 (v/v) as mobile phase. Densitometric quantification was performed at 276 nm by reflectance scanning. Validation of the developed method was conducted as per ICH requirements. The limit of detection and limit of quantitation of zidovudine and lamivudine were established. The developed HPTLC method was found to suitable to check the quality of zidovudine and lamivudine in combined dosage form.