Development and Validation of HPLC/UV-Spectrophotometric Procedures for Metronidazole Quantitative Determination

Abstract

Metronidazole is the most popular representative of antiprotozoal medicines from the group of 5-nitroimidazoles. Metronidazole blocks the enzymes of alcohol dehydrogenase and acetaldehyde dehydrogenase, therefore when its joint taking with alcohol it is observed the strong intoxication syndrome and fatal poisonings too. Therefore metronidazole can be a potential object of chemical toxicological investigations. The purpose of our paper is to develop HPLC/UV-procedure of metronidazole quantification with application of the system of HPLC-analyzer MiLiChrome® A-0230 implemented in practice of forensic medical laboratories in Russia and Ukraine and carry out step-by-step validation of the developed procedure. Chromatographic conditions: Eluent A (0.2 M LiClO4 – 0.005 M HClO4) and Eluent B (acetonitrile) wereused as the mobile phase components; HPLC microcolumn Ø2×75 mm and ProntoSIL 120-5-C18 AQ, 5 μm were used as an analytical column; temperature was 40°С; flow rate was 100 μl/min; gradient elution mode was from 5% to 100% Eluent B for 40 min, then 100% Eluent B for 3 min; detection was performed at 277 nm. Retention time for metronidazole is 5.95 min. Since metronidazole is easy soluble and stable enough in the solutions of diluted alkalis 0.001 M sodium hydroxide solution has been proposed for preparation of the solutions in developing HPLC/UV-procedure of metronidazole quantification. Validation of the procedure has been carried out in the variants of the method of calibration curve and method of standard by such parameters as in process stability, linearity/calibration model, accuracy and precision within 3 different analytical runs using different batches of reagents and different glassware; experiments have been performed by three different analysts. New procedure of metronidazole quantitative determination by the method of HPLC/UV has been developed. Its validation has been carried out and acceptability for application has been shown.