Development of a new liquid chromatography method for quantitative analysis of isoniazid and determination of impurities in active pharmaceutical substances and finished medicinal products.

Isoniazid inhibits DNA-dependent RNA polymerase and the synthesis of mycolic acids in Mycobacterium tuberculosis cells. The drug exhibits high bacteriostatic activity against tuberculosis mycobacteria, effectively halting their growth. Isoniazid is particularly effective in treating acute and active forms of tuberculosis and is included in the tuberculosis management guidelines of all countries. During the quality control stage of pharmaceutical products containing isoniazid, it is necessary to perform quantitative analysis of isoniazid in the tablets and determine any impurities. According to the World Health Organization, current pharmacopoeia methods used for the quality control of isoniazid have flaws, particularly regarding repeatability and stability. Consequently, the World Health Organization has requested the development of a new method. The aim of this master's thesis is to develop a new, stable, and reproducible liquid chromatography method for the quantitative analysis of isoniazid in active pharmaceutical substances and finished medicinal products, as well as for the determination of impurities. In our experiments, we tested analytical columns based on the octadecyl silica gel stationary phase with varying parameters, including column length, inner diameter, pore size, and particle size. We selected the column with optimal characteristics. Subsequently, based on experimental trials, we identified the optimal mobile phases and gradient for this column. Validation of the new method confirmed that it is stable, reproducible, and reliable. Based on this method, the determination of isoniazid and its impurities in active pharmaceutical substances and finished medicinal products yields accurate and reliable results.

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