SPECTROPHOTOMETRIC DETERMINATION OF IZONIAZID AND ITS DERIVATIVES BY REACTION OF FORMATION THE POLYMETHINE DYE WITH 4-OXOURACIL

The process of tuberculosis treatment requires monitoring of the concentration of antituberculosis drugs in the blood, as well as their distribution and elimination from the body to prevent overdose of antituberculosis drugs. Individualizing the dose of drugs possibly including individual activity of the enzyme N-acetyltransferase, may be determined indirectly by biotransformation product of antituberculosis drugs. Currently existing methods for detecting the content of the test drug acetylation of isoniazid - mass spectrometry, high performance liquid chromatography have several major limitations such as the high cost, complexity of tests methods in experimentation. This article demonstrates the results of development of unified methods of quantitative determination of antituberculosis drug isoniazid and its conjugate - acetylizoniazid. The basis of spectrophotometric method is the cleavage reaction of isoniazid pyridine ring to form glutaconic aldehyde and its subsequent combination with the 4-oxouracil with the formation of a polymethine dye. The developed method allows to carry out quantitative determination of isoniazid in the pharmaceuticals forms as well as isoniazid and its derivatives in body fluids (urine), which indirectly makes it possible to evaluate the activity of N-acetyltransferase during pharmacokinetic studies.