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 itraconazole (as internal standard) from 500 µL plasma samples. The chromatographic separation was achieved with an Acquity UPLC BEH C18 column (1.7 µm, 2.1 × 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.