ASSESSMENT OF THE SUITABILITY OF ENZYME-BASED SCREENING IMMUNOASSAY METHOD FOR ESTABLISHING THE WITHDRAWAL PERIOD OF VETERINARY DRUGS BASED ON TRIMETHOPRIM FROM THE ORGANISM OF PRODUCTIVE ANIMALS

In recent years, Ukraine has developed a significant regulatory framework for ensuring the quality of medicines. Accordingly, the requirements for the quality of clinical trials, their legal and methodological framework are constantly increasing, which necessitates further work in this direction. Today, in Ukraine, the main governing document regulating the use of veterinary drugs is the Law of Ukraine "On Veterinary Medicine". In accordance with these requirements, only drugs that are included in the state register and for which a full set of studies to prove efficacy, safety and quality have been conducted, are allowed to be used for the treatment of farm animals. The article summarizes the experience gained by the National Reference Laboratory of Veterinary Drug Residues Control, when using the enzyme-linked immunosorbent assay (ELISA) method to study the withdrawal of trimethoprim from the tissues of productive farm animals to safe residue concentration levels established by the legislation of Ukraine (Order of the Ministry of Health of Ukraine No. 2646 dated 12/23/2019). The stages of clinical trials of veterinary antimicrobial drugs containing the antibiotic trimethoprim are considered, which illustrate the use of standardized approaches to assess the suitability of the above-mentioned methods for experimental purposes. The results of the verification and validation of new Trimethoprim ELISA test kit, developed by EuroProxima (Netherlands), are presented, in accordance with the criteria established by the European Commission Decision 808/2021/EC and the recommendations of EU reference laboratories in the field of residues control of 20/1/2010. In order to confirm the reliability of the results obtained by screening method for tissue samples of target productive animals, the study was carried out by the confirmatory UPLC-MS/MS method. The results of comparative studies are presented in tables. The article also discusses the features of the method, analyzes the possibilities of their influence on the obtained research results, and describes statistical approaches when calculating the predicted withdrawal periods for productive animals in accordance with the recommendations of EMEA/CVMP/036/95-FINAL.