Development and validation of an HPLC/MS/MS method for determining the thiazolidinone PG15 in rat plasma

A rapid, sensitive, and simple HPLC/MS/MS method was developed and validated for the determination of (5Z,E)-3-[2-(4-chlorophenyl)-2-oxoethyl]-5-(1H-indol-3-ylmethylene)-thiazolidine-2, 4-dione (PG15) in rat plasma using chlortalidone as an internal standard (IS). Analyses were performed using a C18 column and isocratic elution with acetonitrile-water (90 + 10, v/v) containing 10 mM ammonium hydroxide (pH 8.0) as the mobile phase pumped at 0.3 mL/min. Detection was performed by MS with negative ion mode electrospray ionization. Rat plasma samples were prepared by deproteinizing with acetonitrile. Detected fragments were 395.1 > 171.9 for PG15 and 337.3 > 189.9 for the IS. Calibration curves were linear from 10 to 1000 ng/mL, with the determination coefficient > 0.99. The intraday and interday precisions were less than 12.2 and 11.3%, respectively. The applicability of the HPLC/MS/MS method for pharmacokinetic studies was tested using plasma samples obtained after oral administration of PG15 to rats, and it provided the necessary sensitivity, linearity, precision, accuracy, and specificity.