Study And Application Of A Quantification Method For Determination Of Gliclazide In Human Plasma By LC/MS/MS

Aim To develop and validate a rapid, sensitive and selective LC/MS/MS method for the determination of gliclazide in human plasma and to evaluate the bioequivalence of gliclazide modified release tablet by the validated LC/MS/MS method.Method After a simple liquid-liquid extraction, the analyte and internal standard glibenclamide was chromatographed on a Zorbax SB C₈ column by a mobile phase of acetonitrile-water-formic acid (180: 20: 1, v/v/v). A tandem mass spectrometer equipped with atmospheric pressure chemical ionization source was used as the detector and was operated in the positive ion mode. Detection of the ions was performed in the selected reaction monitoring (SRM) mode by monitoring the transitions of m/z 324→m/z 127 for gliclazide, m/z 494→m/z 369 for glibenclamide (IS), respectively. The bioequivalence studies of gliclazide modified release tablet were conducted on 20 or 22 healthy male volunteers after a single or multiple doses of 30 mg gliclazide. The pharmacokinetic parameters of test and reference formulations were calculated by non-compartment method. The bioequivalence was assessed through two one-sided test procedures and 90% confidence intervals.Results The assay was reproducible and linear over the range of 1.0 - 4000 ng·mL^-1. The lower limit of quantification of the analyte was 1.0 ng·mL^-1. The intra-day and inter-day precision (RSD) was less or equal to 4.2% and accuracy (RE) was within ±5.1%. The recoveries of the analyte at each concentration level were more than 78%. Each plasma sample was chromatographed within 2.8 min. More than 150 plasma samples could be assayed within each day. Following a single dose of gliclazide test formulation, 90% confidence interval for AUC_0→t and C_max were 96.9% - 118.9% and 86.3% - 111.6%, respectively; Following multiple doses of gliclazide test formulation, 90% confidence interval for AUC_0→t and C_max were 101.1% -120.6% and 103.7% - 125.4%, respectively; And 90% confidence interval for C_min and C_av were 96.1% - 121.8% and 101.8% - 120.4%, respectively. Thus the test formulation of gliclazide was considered bioequivalent to the reference formulation according to both the rate and the extent of absorption.Conclusion The developed LC/MS/MS method is proved to be superior in sensitivity and...