Quantitative methods in the analysis of clozapine in human matrices – A scoping review

Clozapine (CLZ) has retained its clinical utility in the management of schizophrenia despite the discovery of novel antipsychotics, as it possesses unique efficacy in the setting of treatment resistant schizophrenia while causing minimal extrapyramidal symptoms. However, these benefits are offset by the risk of agranulocytosis and other side effects, and therapeutic drug monitoring (TDM) is routinely recommended for patients undergoing treatment with CLZ. A multitude of approaches for the quantification of CLZ have been developed for different settings such as TDM, quality control of pharmaceutical dosage forms, and toxicology studies. Primarily, these approaches fall under one of three branches of analysis, namely, chromatography, electrochemical analysis, and spectrophotometry. This study provides a scoping review of the recent advances in the methods of quantification for CLZ and highlights the potential utility of novel methods in the field of drug quantification.