Original Articles: 2011 Vol: 3 Issue: 4
A Validated LC Method for the Determination of Chiral Purity of (S)-2-azido-3-methylbutanoic acid: A key Raw material of Valganciclovir hydrochloride
Abstract
A simple and accurate normal phase liquid chromatographic method was developed for the determination of chiral purity of (S)-2-azido-3-methylbutanoic acid, S-enantiomer used as key starting raw material in the manufacturing of valganciclovir hydrochloride bulk drug. Chromatographic separation between (S)-2-azido-3-methylbutanoic acid and its opposite enantiomer (R)-2-azido-3-methylbutanoic acid, R-enantiomer was achieved using a Chiralpak IA column using a mobile phase containing n-hexane, ethanol, isopropyl alcohol and tri-fluoro acetic acid (98:1.5:0.5:0.1 v/v/v/v). The resolution between the two enantiomers was found to be more than 2.0. The limit of detection (LOD) and limit of quantification (LOQ) of the Renantiomer
was 0.15 and 0.5 μg mL-1, respectively, for 10 μL injection volume. The percentage recoveries of the R-enantiomer ranged from 96.5 to 105.3 in the samples of (S)-2-azido-3-methylbutanoic acid. The test solution and mobile phase was observed to be stable up to 24 h after the preparation. The developed method was validated as per International Conference on Harmonization guidelines in terms of LOD, LOQ, precision, linearity, accuracy, robustness and ruggedness.