Reliable GC Method for Related Substances in Divalproex Sodium Drug.

A specific GC method has been developed, optimized and validated for the determination of seven related substances namely N,N-dimethyl valpronamide, valeric acid, 2-methyl valeric acid, 2-ethyl valeric acid, 2-isopropyl valeric acid, 2-n-butyl valeric acid and 2-propyl-2-pentenoic acid in divalproex sodium (DPS) drug substance. Chromatographic separations of these seven impurities were achieved on DB-FFAP column (30 m × 0.53 mm, 1.0 μm), which consists nitroterephthalic acid modified polyethylene glycol material as stationary phase. DPS is a coordination complex of the sodium valproate and valproic acid (VPA). Nonanoic acid is used as internal standard. All the seven related substances, VPA and nonanoic acid were extracted into dichloromethane and monitored by GC with flame ionization detector. The performance of the developed method was assessed by evaluating specificity, linearity, sensitivity, precision, accuracy and robustness. Forced degradation experiments were conducted to evaluate the degradation behavior of DPS. The established limits of detection (LODs) and limits of quantification (LOQs) values for the related substances were in the ranges of 4-5 and 12-15 μg mL-1, respectively. Further, for VPA, LOD and LOQ values were 4 and 12 μg mL-1, respectively. The correction factors of these related substances with respect to VPA and lie between 0.92 and 1.44. The average recoveries were in the range of 92.4-108.4%. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Citation

S Raghavender Reddy, K Hussain Reddy, P Madhava Reddy, G Amarnatha Reddy, M Narendra Kumar, Hemant Kumar Sharma. Reliable GC Method for Related Substances in Divalproex Sodium Drug. Journal of chromatographic science. 2017 Oct 01;55(9):891-898

PMID: 29048489

search → result