Rapid, Sensitive, and Validated Hplc Method for Analysis of Metronidazole and Tinidazole Under Identical Chromatographic Conditions With Uv Detection and Liquid-Liquid Extraction: Application in Bioequivalence Studies Publisher



Emami J¹ ; Rezazadeh M¹
Source: Acta Chromatographica Published:2013

Abstract

A simple, rapid, and sensitive reversed-phase HPLC method was developed and validated for determination of metronidazole and tinidazole in human plasma samples under identical chromatographic conditions. This method involves liquid-liquid extraction using chloroform: isopropylalcohol (95:5). Chromatographic separation was performed using a μ-bondapack C18 (250 mm × 4.6 mm) column. The mobile phase consisted of potassium dihydrogen phosphate solution (0.005 M)/acetonitrile (80/20 v/v). The final pH of the mobile phase was adjusted to 4 ± 0.1 with orthophosphoric acid. The calibration curves were linear over the concentration range 0.1-15 μg/mL for metronidazole and tinidazole with the detection limit of 30 ng/mL. Within-and between-day precision and accuracy did not exceed 9.83% and 10.48%, respectively. Metronidazole and tinidazole were found to be stable in plasma samples with no evidence of degradation during 3 freeze-thaw cycles and 3 months storage in-70 C. The current validated bio-analytical method was finally applied in bioequivalence studies of two different metronidazole and tinidazole products according to a standard two-way cross-over design with a two-week washout period. No statistically significant difference was observed between the logarithmically transformed AUC0- and Cmax values. Therefore, generic products were considered bioequivalent with those of standards which could be used interchangeably.