Rapid and Simple Method for the Determination of Pregabalin in Human Plasma using Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS): Application to a Bioequivalence Study of Daewoong Pregabalin Capsule To Lyrica®Capsule (Pregabalin 150 mg)

Abstract

Method using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of pregabalin in plasma samples. Acquisition was performed by monitoring the tran- sitions: m/z 160.1→142.2 for pregabalin and m/z 423.2→207.1 for losartan (as an internal standard). After cold acetonitrile- induced protein precipitation of the plasma samples, separation was performed with C18 column by isocratic mobile phase consisted of 10 mM ammonium acetate and acetonitrile (15:85, v/v). Results were linear over the concentration ranged from 0.1 to 10 µg/mL and the correlation coefficients (r) were ≥0.99. Intra- and inter-day precisions were ≤6.02 and ≤11.04%, respectively, and intra- and inter-day accuracies were 96.60-101.09 and 98.10-102.60%, respectively. This validated method was successfully applied to a bioequivalence study of two formulations of pregabalin, Daewoong pregabalin capsule (Dae- woong Pharm. Co., Ltd.) and Lyrica ® capsule (Pfizer Korea Ltd.) in twenty eight healthy Korean volunteers. The subjects received a single oral dose of each formulation (150 mg as pregabalin) in a randomized 2 × 2 crossover study and plasma samples were obtained from each subject at predetermined time intervals. Then, the pharmacokinetic parameters (AUC0-t, Cmax and Tmax) were calculated and statistically analyzed to assess the differences between two formulations. The 90% con- fidence intervals for the log-transformed data were acceptable range of log 0.8-log 1.25 (e.g., log 1.0048-log 1.0692 for AUC0-t, log 0.9142-log 1.0421 for Cmax). Thus, AUC0-t and Cmax met the criteria of the Korea Food and Drug Administration (KFDA) for bioequivalence test indicating that Daewoong pregabalin capsule was bioequivalent to Lyrica ® capsule.