Tandem Mass Spectrometric Method for the Estimation of Meloxicam in Plasma Samples: Application to Pharmacokinetic Studies

Abstract

A simple sensitive and specific tandem mass spectrometric (LC-MS/MS) method for the determination of meloxicam in human plasma using Phenomenex Gemini C₁₈ column (50 mm × 4.6 i.d, 5 μm) was developed. The analyte and the internal standard repaglinide were extracted from plasma by liquid-liquid extraction and a mixture of 5 mM ammonium acetate (pH 5.5 ± 0.3) and acetonitrile in the ratio of 10:90 (v/v) was used as mobile phase. The retention times of meloxicam and internal standard were 0.96 and 1.52 min, respectively. Detection was carried out using API 3200 (MDS Sciex) with a mass spectrometer operating in selected reaction monitoring mode. The flow rate maintained was 0.800 mL/min with a run time of 2.2 min. The method had a lower limit of quantification of 1 ng/mL. The calibration curve was demonstrated to be linear over the concentration range of 1.00 to 2503.85 ng/mL. The within-batch and between batch precision values for meloxicam at lower limit of quantification are 5.8 to 7.9 % and 7.9 % and accuracy are 93.6 to 103.8 % and 97.9 %, respectively. The pharmacokinetic parameters for meloxicam was found to be T_max-4.6 h, C_max-1014.2 ng/mL, t_1/2- 18.8 h, AUC_0-T-10142.0 ng/mL and AUC_0-¥-10333.5 ng/mL. The entire results obtained in the study were well acceptable to a pharmacokinetic study in human volunteers.