DEVELOPMENT OF A METHODOLOGY FOR THE ANALYSIS OF SOME PSYCHOTROPIC SUBSTANCES BY THE TLC METHOD

235 Volume 5, Issue 10: Special Issue (EJAR) ISSN: 2181-2020 MPHAPP THE 6TH INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE “MODERN PHARMACEUTICS: ACTUAL PROBLEMS AND PROSPECTS” TASHKENT, OCTOBER 17, 2025 in-academy.uz DEVELOPMENT OF A METHODOLOGY FOR THE ANALYSIS OF SOME PSYCHOTROPIC SUBSTANCES BY THE TLC METHOD Abdullayeva M.U. Olimov N.K. Sidametova Z.E. Shermatova M.I. Tashkent Pharmaceutical Institute, Tashkent city, Republic of Uzbekistan e-mail: [email protected] https://doi.org/10.5281/zenodo.17333411 Relevance. The study of medicinal products containing psychotropic substances should be carried out using a simple, accessible, and rapid method - thin-layer chromatography. The advantages of the method - rapid separation, high resolution, sensitivity, and ease of sorbent preparation - are the main reasons for its widespread use in the expert analysis of numerous pharmaceutical products and complex medicinal mixtures. The TLC method offers significant advantages over chemical methods, particularly when analyzing multicomponent drug mixtures. It enables the separation and identification of individual constituents, as well as substances with similar chemical structures and properties. The aim of our research is to develop a methodology for investigating certain psychotropic substances frequently encountered in forensic practice using the TLC method. The selection of a solvent system is carried out taking into account the polarity of the studied compounds, as well as the activity of the sorbent. When separating substances with similar absorption properties, a mixture of solvents located close to each other in the eluotropic series should be used. The content of the more polar solvent in this mixture typically ranges from 1 to 10%. The final choice of solvent system is achieved through experimental analysis. Materials and Methods. The study subjects were standard solutions of psychotropic substances of the benzodiazepine series. The analysis was performed using a laboratory thin-layer chromatography equipment set consisting of an ultraviolet light source (illuminator), an iodine chamber, UV-254 silufol tablets, Dragendorff-Mounier reagent, an MS-10 microsyringe, a crucible, a sprayer, and organic solvents: benzole, ethanol, diethylamine, chloroform, and ethyl acetate. Psychotropic tablets are ground to a powder and used to prepare 0.1% and 0.2% alcohol solutions. Alcohol solutions are filtered through filter paper and analyzed using thin-layer chromatography. Results. The results of a study of the chromatographic mobility of psychotropic benzodiazepine derivatives in thin layers of a benzole-ethanol-diethylamine (9:1:1) sorbent system are presented in Table 1. Table 1. N Name Rf Glow Under UV rays Detection in iodine vapor Dragendorff reagent 1 2 3 4 5 Alprozalam Bromazepam Diazepam Clonazepam Lorazepam 0,45 0,57 0,51 0 0,44 light lilac - " - dark violet - lilac bright yellow - " - white - yellowе orange orange yellow - orange 236 Volume 5, Issue 10: Special Issue (EJAR) ISSN: 2181-2020 MPHAPP THE 6TH INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE “MODERN PHARMACEUTICS: ACTUAL PROBLEMS AND PROSPECTS” TASHKENT, OCTOBER 17, 2025 in-academy.uz Analysis of the table data indicates that the elution capacity of this solvent system varies for the psychotropic substances studied. For example, the system is ideal for separating alprazolam, bromazepam, diazepam, and lorazepam, but is ineffective for clonazepam. Conclusions. A system consisting of benzole - ethanol - diethylamine = 9:1:1 is ideal for the separation of psychotropic substances - benzodiazepine derivatives alprazolam, bromazepam, diazepam, lorazepam. In this case, their Rf values, the color of the spots when illuminated by UV rays, developed in iodine vapor and with the Dragendorf reagent were determined.