www.pharmanest.in PHARMANEST Vol.1 (1) Sep-Oct-2010 An International Journal of Advances In Pharmaceutical Sciences 22 RESEARCH ARTICLE VALIDATED HPLC METHOD FOR DETERMINATION OF LAMIVUDINE AND STAVUDINE IN THEIR FORMULATIONS CH.BALASEKARREDDY 1 , BAHLUL Z.AWEN 2 , CH.BABU RAO* 2 , N.SREEKANTH 3 and P.RAMALINGAM 4 1 Apotex research Pvt.ltd. (A division of Canadian MNC), Bangalore-560099, India. 2 Faculty of Pharmacy, Al-Jabal Al-GharbiUniversity, Alzawia, Libya. 3 Department of Pharmacy, College of Public Health and Medical sciences, Jimma University, Jimma, Ethiopia. 4 Raghavendra Institute of Pharmaceutical Education and Research, Ananthapur, (A.P), India. ABSTRACT A simple, rapid, precise and accurate isocratic reverse phase stability indicating RP-HPLC method was developed and validated for the simultaneous estimation of Lamivudine and Stavudine in commercial tablets. The method has shown adequate separation for Lamivudine (RT-3.087) and Stavudine (RT-6.09) respectively. Separation was achieved on an YMC pack, C8, 150mmX4.6mm, 5μ column using a mobile phase consisting of buffer pH 3.5 and methanol in the ratio of 90:10v/v at a flow rate of 1.0ml/min. the detection was carried out by PDA detector at the wavelength maximum of 265 nm. The drugs were subjected to acid degradation, base degradation, peroxide degradation, thermal degradation, photolytic degradation and humidity degradation. The linearity of proposed method was investigated in the range of 5-50 μg/ml (r= 0.99989) for Stavudine and 20-220μg/ml (r= 0.99997) for Lamivudine, respectively. KEY WORDS: Stavudine, Lamivudine, Degradation, RP-HPLC. INTRODUCTION Fig.1.Chemical structures of Stavudine and Lamivudine Lamivudine is a synthetic nucleoside analogue, showing a potent inhibition of the human immunodeficiency virus (HIV–1) the causative agent of acquired immunodeficiency syndrome (AIDS). Chemically Lamivudine is a (2R-cis)-4-Amino-1-[2- (hydroxymethyl)-1, 3-oxathiolan-5-yl-2(1H)- pyrimidinone having molecular formula C8H11N3O3S. Lamivudine is a nucleoside reverse transcriptase (NRT) inhibitor of human immunodeficiency virus type 1 (HIV-1). It is a chain terminator, and all three phosphorylation events to give the triphosphate are carried out by cellular enzymes. The chemical structures of Stavudine and Lamivudine was shown in Fig.1. The first phosphorylation is by a cellular deoxy cytidine kinase rather than a viral kinase .Intracellularly, Lamivudine is phosporylated to its active 5 1 – triphosphate metabolite, Lamivudine triphosphate (L- TP). The principal mode of action of L-TP is the