Determination of Pinaverium Bromide in Human Plasma by a Sensitive and Robust UPLC-MS-MS Method and Application to a Pharmacokinetic Study in Mexican Subjects

A high-throughput ultra-performance liquid chromatography coupled to tandem mass spectrometry (LC-ESI-MS-MS) method was developed for the determination of pinaverium bromide in human plasma. Protein precipitation with acetonitrile was used to extract pinaverium and itraco-nazole (as internal standard) from 500 mu L plasma samples. The chromatographic separation was achieved with an Acquity UPLC BEH C18 column (1.7 mu m, 2.1 x 100 mm) using a mixture of acetonitrile-5 mM ammonium formate (80:20, v/v) as mobile phase. Isocratic elution at 0.3 mL/min was used. Detection was performed by positive ion electrospray tandem mass spectrometry on a XEVO TQ-S by multiple reaction monitoring mode. The mass transitions monitorized were as follows: m/z 511.2 -> 230 for pinaverium bromide, and m/z 705.29 -> 392.18 for the itraconazole. The method was validated over a concentration range of 12-12,000 pg/mL. The chromatographic method runtime is 2.5 min and was applied to characterize the pharmacokinetics of pinaverium bromide after the oral administration of 100 mg to healthy Mexican subjects.