Objects – amlodipine besylate, verapamil hydrochloride, diltiazem hydrochloride, sodium 1,2-naphthoquinone-4-sulfonate, bromocresol green, spectrophotometry, quantitative determination, validation; aim – development and validation of non-extractive methods of spectrophotometric determination of drugs, calcium channel blockers; methods – general scientific, physical and chemical, mathematical and statistical; novelty – the possibility of using sodium 1,2-naphthoquinone-4-sulfonate and bromocresol green in the practice of pharmaceutical analysis for quantitative spectrophotometric determination of drugs, calcium channel blockers, was first experimentally proved and scientifically substantiated; optimal conditions for the reaction of used colorreagents with medicinal substances, calcium channel blockers, namely sodium 1,2-naphthoquinone-4-sulfonate with amlodipine besylate, bromocresol green with verapamil hydrochloride and diltiazem hydrochloride, without extraction of ionic associates, are calculated, analytical sensitivity parameters are calculated; methods of quantitative determination of amlodipine besylate, verapamil hydrochloride and diltiazem hydrochloride in 13 pharmaceutical forms of industrial production have been developed, validation characteristics are proved the correctness of the proposed methods; the stoichiometric ratio of "reagent - drug substances" was determined and the probable chemistry of the reactions of the proposed color reagents with the investigated drugs was proposed; the products of the BCG reaction with verapamil hydrochloride and diltiazem hydrochloride were isolated and identified; results - the quantitative determination of drugs, calcium channel blockers, was carried out by absorption spectrophotometry in the visible spectral region, taking into account the requirements of the article of the State Pharmacological Center "Absorption spectrophotometry in the ultraviolet and visible spectral regions"; to process the received spectra, the software package WinASPECT 2.2.1.0 .; the stoichiometric ratio of the reactants was determined by spectrophotometric methods: the saturation method (by the molar ratio method), the method of continuous changes (by the method of isomolar series) and the method of relative yield (by the Staryk-Barbanel method); determination of the structure of the reaction products between the investigated medicinal substances and bromocresol green was carried out by IR spectrophotometry, 1H NMR spectrometry; validation of the developed methods and statistical processing of the obtained results were carried out in accordance with the requirements of the Ukrainian State Pharmacopeia; introduced – into the educational process of higher educational institutions; branch – pharmacy.
