Development and Validation of HPLC Method for Simultaneous Estimation of Reduced and Oxidized Glutathione in Bulk Pharmaceutical Formulation

The objective of this study was the development, optimization, and validation of a RP-HPLC method for the quantification of reduced glutathione (GSH) and oxidized glutathione (GSSG) in pharmaceutical formulations The separation utilized a C18 column at room temperature with absorption wavelength 210nm. The mobile phase was an isocratic flow of a 95:5 (v/v) mixture of 25mM phosphate buffer (pH 2.7) and methanol with flow rate at 1.0 mL/min. Validation of the method assessed with the methods ability in seven categories: linearity, range, limit of detection, limit of quantification, accuracy, precision, and selectivity. The method show an acceptable degree of linearity with r²=0.9994 and 0.999 over a concentration range of 10-200 μg/mL for GSH and GSSG respectively. The detection limit and quantification limit for GSH 20.7μg/mL and 69.24μg/mL and for GSSG 17.22μg/mL and 57.42μg/mL respectively. The percent recovery of the method was 99.98-100.93 %. Following validation, the method was employed in the determination of glutathione in pharmaceutical formulations in the form of a liposome. The proposed method offers a simple, accurate, and inexpensive way to quantify reduced glutathione.