Introduction. Lately, medical services have reported a lot of cases caused by taking Tropicamide alone or with other drugs together. Moreover, it has been declared that the increase in the number of resistance cases to Tropicamide consumption has. Due to those facts, Tropicamide was included in the List of Drugs for Medical Use that should be served by the prescriptions in 2015. However, nowadays in Russia there are many combinations of medicines, for instance, Tropicamide and α-adrenergic agonist (phenylephrine) (Midrimax, Fenikamid, Appamide plus) that are not under that regulation. As a result, those medicines are served in pharmacies without any prescriptions. Thus, method developing for Tropicamide determination in the hair samples to establish his consumption period has become a perspective one.Aim. The research aimed to develop a method for the isolation and determination of Tropicamide in the hair samples.Materials and method. Reference standard of Tropicamide was used in this research. The following enzymes – papain, chymopsin, chymotrypsin, and hyaluronidase – were applied in the experiment. To design the long-term consumption of Tropicamide, laboratory animals (Guinea pigs, average masses about 200 – 250 g) with fair and brown nature colour hair were used in this research. The hair of laboratory animals was dyed by professional hair-dye "Estel Professional De Luxe". The following equipment was applied: balance "Sartorius СР224S", pH-meter " FiveEasy ", ball mill Retsch MM-200. The hair samples extracts were analyzed by gas chromatography with mass selective detection (Gas chromatograph model 7890А with mass selective detector model 5977 and MassHunter GC/MS software by Agilent Technologies).Results and discussion. All developed methods of enzymatic hydrolysis (by papain, chymopsin, chymotrypsin, and hyaluronidase) revealed comparable results for the Tropicamide determination in the hair samples. The research showed that the amount of the analyte isolated from the pigmented hair was a bit higher in comparison with the other hair samples (fair hair), despite the melanin gives chemical steadiness property to hair stuff. Moreover, the amount of Tropicamide extracted from the dyed hair samples increased by 30 %. The degradation products of the analyte of interest were not found in the extracts obtained for the dyed hair samples. Thus, the colorant does not destroy the xenobiotic during the hair dying procedure and does not impact the enzymatic hydrolysis process. The values of the validation parameters (precision and accuracy) met the required criteria for bioanalytical methods. Therefore, the enzymatic hydrolysis method can be recommended for application in laboratory practice.Conclusion. In the course of the study, a method for laboratory diagnostics of non-drug use of tropicamide was developed, the reproducibility of which meets the acceptance criteria for bioanalytical methods, which makes it possible to recommend it for work in laboratory practice.
