A novel method for the therapeutic drug monitoring of biperiden in plasma by GC-MS using salt-assisted liquid–liquid microextraction

Abstract

Biperiden is an anticholinergic agent with central effects. It is used in Parkinson's syndromes and in the treatment of extrapyramidal symptoms that occur with the use of various agents (neuroleptics, antipsychotics). It causes anticholinergic syndrome in high doses. For this reason, therapeutic drug monitoring of biperiden is important. This study, it was aimed to develop a validated GC-MS method for the therapeutic monitoring of biperiden in human plasma. Biperiden and internal standard biperiden-d5 were extracted from plasma using the salt-assisted liquid–liquid extraction method. The method was validated according to the European Medicines Agency (EMA), Bioanalytical method validation guidelines. The lower limit of quantification of the developed method was chosen as 0.5 ng/mL. The calibration curve of biperiden for the method was validated between 0.5 and 15 ng/mL, showing correlation coefficients >0.99. In addition, the developed method was used for the therapeutic drug monitoring of biperiden in real patient plasma.