Validation of method for the quantitative determination of carbamazepine in blood serum and urine by high performance liquid chromatography using an internal standard

Introduction. According to the Order of the Ministry of Health of the Russian Federation dated June 30, 2022 No. 453n "On approval of the Procedure for dispensary supervision of a person suffering from chronic and prolonged mental disorder with severe persistent or often aggravated painful manifestations", it is required to measure the concentration of drugs in patients 2 times a year. The heads of the executive bodies of the subjects of the Russian Federation in the field of healthcare are recommended to organize control over the treatment of socially dangerous patients. The list of medicines to be controlled includes: chlorprotixen, thioridazine, respiridon, triftazine, haloperidol. chlorpromazine, carbamazepine, quetiapine, etc. There is an urgency in the development of quantitative determination techniques both for the observation of persons suffering from mental disorders and for the production of research in medical toxicology. Validation of the methods serves as a guarantee that the results of the analysis are reliable and accurate.

Goal – to develop and validate a methodology for the quantitative determination of carbamazepine by high-performance liquid chromatography (HPLC) with diode-matrix detection using an internal standard.

Material and methods. The quantitative determination of carbamazepine by HPLC was carried out in model mixtures of blood serum and urine after introducing an internal standard into them and extraction with chloroform. The following are determined: linearity, specificity, correctness, precision (under conditions of repeatability). The minimum analyzed concentration of carbamazepine is 0.50 mcg/ml, the maximum is 50.0 mcg/ml.

Results. It was established: the dependence graphs are linear in nature, for blood serum the correlation coefficient was 0.99933, for urine – 0.99900; the methods are specific, which is confirmed by the absence of extraneous peaks in extracts from "blank" samples of blood serum and urine, coinciding in retention time with the studied substances; indicators of relative standard deviation they do not reach 7%, the relative error is less than 8%.

Conclusions. The features of the quantitative determination of carbamazepine by HPLC using an internal standard have been studied. The obtained results are reproducible and, with the help of validation, their suitability for therapeutic monitoring, chemical and toxicological research, and forensic chemical analysis has been confirmed.