Application of the chromatographic method for the analysis of azithromycin in a model mixture

Application of the chromatographic method for the analysis of azithromycin in a model mixture
Kasimova D.B., Tillaeva G.O’., Gaibnazarova D.T., Sadikova G.I., Allanazarova M.,

Tashkent Pharmaceutical Institute, Tashkent, Uzbekistan

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Azithromycin is the most commonly prescribed macrolide, which is associated with a number of unique pharmacokinetic and pharmacodynamic properties of the drug, allowing it to be one of the most popular macrolide antibiotics for various types of infectious diseases for more than 10 years.
Azithromycin is a semi-synthetic antibiotic of the third generation and has a high microbiological and clinical efficacy in the treatment of a number of severe infections of the respiratory tract, skin and soft tissues, and some urogenital infections.
Purpose: The purpose of this study was to develop a thin layer chromatography (TLC) method for the determination of azithromycin.
Methods and materials. Azithromycin in a model mixture, thin layer chromatography.
Results and discussion. When developing a technique for chromatography in a thin layer of a sorbent, the substance of azithromycin was used, which meets the requirements of the pharmacopoeial article of the State Pharmacopoeia, XXII ed. (FS 42-0213-07), organic solvents of different polarity, analytical grade. Chromatographic studies were carried out in a glass N-chamber of rectangular cross section in height, which was preliminarily saturated with mobile phase vapor for 30 min at a constant temperature. Upward chromatography was performed on Silufol UV-254 100x100 mm plates. The height of the eluent front was 100 mm. In parallel, by successive dilutions, solutions of the working standard sample (RCO) of azithromycin were prepared with a concentration of 0.1% (solution A), 0.05% (solution B), 0.02% (solution C). Only freshly prepared solutions were used in the work. Taking into account the requirements for sample preparation and the solubility of the analyte, chloroform was chosen as a solvent. The plate with the applied samples was dried and chromatographed by the ascending method. The spots of the obtained chromatograms were opened when viewing in UV light at a wavelength of 254 nm, while comparing the Rf values ​​of the studied samples and RCO. The suitability of the chromatographic system was evaluated by the following parameters: a spot is clearly visible on the chromatogram of solution C of azithromycin. Statistical processing of the research results was carried out according to GFCI ed. using the Microsoft Excel 2011 software package (product number 54521-701-3227086-17559). The significance of differences was assessed using Student's t-test at a significance level of p <0.05.
The composition of the mobile phase was selected by mixing solvents from the beginning and end of the eluotropic series in various ratios. The polarity of the combined eluents was estimated from the value of the permittivity and the volume fraction of the individual solvents that make up the PF. It was found that the optimal mobility of azithromycin is observed in the binary systems chloroform-acetone (1:5) - Rf=0.58 and chloroform-ethanol (1:1) - Rf=0.51, for which the average approximate value of the permittivity was 17.9 and 14.6 respectively.
Conclusion. Thus, on the basis of the study, the choice of solvents and conditions for the identification of azithromycin from the model mixture by TLC was made, and a method for extracting the antibiotic from the model mixture was proposed, some metrological characteristics of the qualitative analysis of the model mixture of azithromycin using thin layer chromatography were found.