Bioanalytical method for quantification of Solifenacin in rat plasma by LC-MS/MS and its application to pharmacokinetic study

Background: Solifenacin succinate is a competitive muscarinic acetylcholine receptor antagonist used in the treatment of overactive bladder with or without urge incontinence. Methods: Liquid chromatography–tandem mass spectrometry method was used for quantification of Solifenacin (SF) in rat plasma. Solifenacin-d5 (SFD5) used as an internal standard. Chromatographic separation was performed Gemini-NX C18, 50 × 4.6 mm, 5 μm, 110 Å column. Mobile phase composed of 5 mM Ammonium formate, pH 3.0: methanol (20:80 v/v), with 0.4 mL/min flow-rate. Drug and IS were extracted by Liquidliquid extraction method. SF and SFD5 were detected with proton adducts at m/z 363.2®193.2 and 368.2®198.2 in multiple reaction monitoring (MRM) positive mode respectively. The method was validated with the correlation coefficients of (r2) ≥ 0.9975 over a linear concentration range of 0.1-100.0 ng/mL. Results: This method demonstrated intra and inter-day precision within 1.09 to 4.84 and 1.75 to 7.68 % and accuracy within 101.21 to 106.67 and 97.94 to 104.79 % for SF. Conclusions: This method is successfully applied in the Pharmacokinetic study of rat plasma.