QUANTITATIVE EVALUATION OF IMPURITIES G AND S IN VALACICLOVIR HYDROCHLORIDE HYDRATE ACTIVE PHARMACEUTICAL INGREDIENT USING LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY ANALYTICAL METHOD

Current work makes known that Liquid Chromatography-Mass Spectrometry (LC-MS) method development and validation for the impurity G (N, N -dimethylpyridin-4-amine) and impurity S (2-[(2-amino-6-oxo-1,6-dihydro-9H-purin-9-yl) methoxy] ethyl N-[1,1-dimetylethoxy) carbonyl]-L-valinate) in Valaciclovir Hydrochloride Hydrate active pharmaceutical ingredient (API). The developed LC-MS analytical method is complimentary to the thin layer chromatography (TLC) method available for impurity G and impurity S quantitation in the Valaciclovir Hydrochloride Hydrate API monograph. Impurity G and Impurity S were determined by the LC-MS method in Q1 Multiple ion mode using Ascentis Express C18 (15cm X 4.6 mm) 2.7µm analytical HPLC column. A gradient system was employed for the elution of analytes using acetonitrile (Eluent B) and 0.01M Ammonium Formate, LC-MS compatible volatile buffer, pH 3.0 (Eluent A) in distinct compositions. The gradient system (T/%B) was applied as 0.01/5, 4.00/5, 7.50/80, 10.00/80, 12.50/5, and 20.00/5. A method developed was validated considering the International Conference on Harmonization pharmaceutical guidelines. The quantitation limit found for Impurity G and Impurity S were 207.20ppm and 216.00 ppm.