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: abdullayeva19530101@gmail.com
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.
