STABILITY-INDICATING METHOD DEVELOPMENT AND VALIDATION OF LAMIVUDINE AND TENOFOVIR DISOPROXIL FUMARATE BY USING RP-HPLC
A novel rapid, sensitive and reproducible stability-indicating RP-HPLC method has been developed and validated for quantitative analysis of Lamivudine (LAM) and Tenofovir disoproxil fumarate (TDF) in the bulk drug and in a pharmaceutical dosage form. Use of Thermo C18 analytical column (250mm×4.6 mm, 5.0μm) with 20mM KH2PO4: methanol 30:70% v/v as isocratic mobile phase enabled separation of the drug from its degradation products. UV detection was performed at 270nm. The method was validated for linearity, accuracy (recovery), precision, specificity and robustness. The linearity of the method was satisfactory over the range 5-25μg/ml (correlation coefficient 0.999 for LAM and 0.998 for TDF). The limits of detection and quantification of LAM and TDF were 0.45, 0.35 and1.35, 1.15μg/ml respectively. Recovery of LAM and TDF from the pharmaceutical dosage form ranged from 98.75-99.87 and 98.63-99.30% respectively. LAM and TDF were subjected to stress conditions (hydrolysis (acid, base), oxidation and thermal degradation). Samples were analyzed by this method. Extensive degradation of LAM was found under acid and alkaline hydrolysis. The degradation products were well resolved from main peak. The forced degradation study prove the stability indicating power of the method and therefore the validated method may be useful for routine analysis of LAM and TDF in bulk drug and respective dosage forms for dissolution studies and as stability indicating assay method in pharmaceutical laboratories and industries.
Keywords: Lamivudine, Tenofovir disoproxil Fumarate, RP-HPLC, Method validation, Forced degradation