Development and validation of GC/MS method for determination of pramipexole in rat plasma

A simple, rapid and sensitive method has been developed and validated for the determination of pramipexole in rat plasma by using gas chromatography mass spectrometry. The lower limit of quantification (LLOQ) is superior to the other reported LC-MS/MS methods. After being made alkaline with NaOH, plasma samples (0.1 mL) were subjected to liquid-liquid extraction using methyl-t-butyl ether. Analytes were determined using electron impact ionization in a single quadrupole mass spectrometer. GC/MS was performed in the selected ion monitoring mode using target ions at m/z 211, 212 and 152 for pramipexole and m/z 194 and 165 for caffeine as internal standard. A linear calibration curve was plotted over the range of 20-1000 pg/mL for pramipexole (r(2) > 0.996). The LLOQ was 20.0 pg/mL, respectively, which offered high sensitivity and selectivity enough for bioanalytical investigation. Inter- and intraday precisions ranged from 0.3 to 8.8% and from 0.9 to 11.33%, respectively. The recovery of pramipexole from plasma ranged from 82.4 ± 7.1 to 87.8 ± 5.7%. The method fulfills all standards required for bioanalytical methods and can be successfully applied to a pharmacokinetic study of pramipexole in rats.