RAMAN SPECTROSCOPIC IDENTIFICATION OF SULFAMETHOXAZOLE IN PHARMACEUTICAL DOSAGE FORMS

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: [email protected] 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 20th 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 R532 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 (SO2), aromatic ring, isoxazole, and amino (–NH2) groups are present. The main peaks include characteristic sulfonyl vibrations observed at ≈1090, 1142, and 1154 cm-1, which correspond to νsym(SO2), νas(SO2), 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 –NH2 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.