267
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
RAMAN SPECTROSCOPIC IDENTIFICATION OF SULFAMETHOXAZOLE IN
PHARMACEUTICAL DOSAGE FORMS
N.B. Saidkarimova
A.N. Yunuskhodjayev
Tashkent Pharmaceutical Institute, Tashkent city, Republic of Uzbekistan
e-mail: nodira_botirovna@mail.ru
https://doi.org/10.5281/zenodo.17334129
Introduction.
Sulfonamides are a group of compounds with antibacterial activity that have
been widely used in medicine since the early 20
th
century. These substances exert a bacteriostatic
effect by inhibiting the growth and reproduction of microbial cells. The mechanism of action of
sulfonamides is based on the disruption of the biosynthesis of essential metabolites in bacteria, such
as folic acid and dihydrofolate.
Given such an important biochemical mechanism, the analysis of sulfonamides, the study of
their structure, and their accurate identification are of great significance in modern research. For this
purpose, highly sensitive and efficient spectroscopic techniques are required. In particular, Raman
spectroscopy has been recognized as a reliable and relevant method for the identification of
compounds like sulfonamides, which exhibit characteristic vibrational modes in their molecular
structure.
Materials and methods.
The analyses on Raman spectrometer were performed on a model R-
532 with a spectral range from 100 to 6000 cm
-1
, the spectral resolution of 5-8 cm
-1
, laser wavelength
532 nm, laser power 50 mW, linear CCD array, pixel number 3648, focal length 75 mm, entrance
aperture 20-30 microns, holographic diffraction grating 1800 lines/mm.
The aim of the study
is to investigate the Raman spectra of sulfamethoxazole-containing tablet
and suspension dosage forms, and to evaluate the potential of Raman spectroscopy for the
identification of the active pharmaceutical ingredient within these formulations.
In the Raman spectrum of sulfamethoxazole, one of the sulfonamide drugs containing a
heteroaromatic ring, all characteristic bands corresponding to the sulfonyl (SO
2
), aromatic ring,
isoxazole, and amino (–NH
2
) groups are present. The main peaks include characteristic sulfonyl
vibrations observed at ≈1090, 1142, and 1154 cm
-1
, which correspond to ν
sym
(SO
2
), ν
as
(SO
2
), and
their combinations. The ring-breathing mode of the para-substituted aromatic ring is clearly expressed
at ≈1003–1015 cm
-1
. In the region of 1500–1650 cm
-1
, two distinct peaks are observed at ≈1589 and
≈1634 cm
-1
, which correspond to aromatic ν(C=C) vibrations and deformation modes of the –NH
2
group, while N–H stretching vibrations are recorded in the ≈3300–3470 cm
-1
range. The skeletal
vibration of the isoxazole ring is located at 923 cm
-1
(Figure 1).
Figure 1. Raman spectrum of sulfamethoxazole substance
268
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
In the course of the study, the Raman spectra of sulfamethoxazole-containing suspension and
tablet dosage forms were also recorded, and the presence of their characteristic scattering peaks were
observed.
Conclusion.
The results of the study demonstrated that characteristic Raman scattering bands
of sulfamethoxazole were clearly observed in both suspension and tablet dosage forms. This confirms
that Raman spectroscopy can be regarded as a reliable method for the identification of
sulfamethoxazole in pharmaceutical formulations.
