Determination of Residual Epichlorohydrin in Sevelamer Hydrochloride by Static Headspace Gas Chromatography with Flame Ionization Detection

A sensitive static headspace gas chromatographic method was developed and validated for the determination of residual epichlorohydrin (ECH) in sevelamer hydrochloride (SVH) drug substance. This method utilized a Phenomenex Zebron ZB-WAX GC column, helium as carrier gas with flame ionization detection. The critical experimental parameters, such as, headspace vial incubation time and incubation temperature were studied and optimized. The method was validated as per United States Pharmacopoeia (USP) and International Conference on Harmonization (ICH) guidelines in terms of detection limit (DL), quantitation limit (QL), linearity, precision, accuracy, specificity and robustness. A linear range from 0.30 to 10 μg/mL was obtained with the coefficient of determination (r²) 0.999. The DL and QL of ECH were 0.09 μg/mL and 0.30 μg/mL, respectively. The recovery obtained for ECH was between 91.7 and 96.6%. Also, the specificity of the method was proved through gas chromatography mass spectrometry (GC-MS). This method was applied successfully to determine the content of residual ECH in SVH bulk drug.