Alina Alekseevna Posokhina

Spectrophotometry is a reliable and widespread physical-chemical method used for the quantitative analysis of pharmaceutical products. However, its use for the analysis of substances is limited due to the lack of government-approved standard samples. Currently, the search for optical reference samples and the development of methods using them are relevant tasks in pharmaceutical analysis. The study focused on the antiretroviral drug darunavir, as it is a preferred choice in antiretroviral therapy regimens. The article discusses the optical properties of darunavir, including the choice of the analytical wavelength of 263 nm, optimal solvent methylcarbaryl solution 95%, the analytical concentration, and the optical reference sample of nicotinic acid. The external optical reference sample was selected based on the analytical wavelength of darunavir, the optimal solvent, and the optimal absorption region of the reference sample. The high degree of purification of the nicotinic acid sample, as well as the stability of the concentration of the resulting solutions based on it, allows us to use nicotinic acid as a standard for the quantitative determination of substances using spectrophotometry. The developed method for the quantitative determination of darunavir in substances and dosage forms using spectrophotometry is a modern tool for assessing the quality of drugs. This method allows for accurate measurement of the concentration of the active substance, as well as the registration and evaluation of the intensity of light absorption by the drug molecules in a specific wavelength range, using reference samples. Based on the validation of the specificity, scope of application, linearity, and convergence of the analysis results, the method can be used for the pharmaceutical analysis of darunavir. The relative error of the spectrophotometric determination of darunavir based on nicotinic acid does not exceed 0.57% in the substance and 1.62% in the tablets. The data obtained confirm that the method is sufficiently accurate and allows for reproducible and reliable results both when analyzing the pure substance of the drug and in the composition of the tablet

Angioprotective collection includes raw materials: Aesculi hippocastani semina, Calendulae officinalis flores, Aroniae melanocarpae sicco fructus, Bupleuri multilervis herba, Filipendulae ulmariae flores, Fragariae vescae folia. In terms of the content of biologically active substances (BAS), the raw materials of the collection components met the requirements of regulatory documents. The purpose of the study was to determine the quantitative content in the collection of BAS, which are the main contribution to the development of angioprotective action. The task of the study was to determine the content of BAS of a phenolic nature, amino acids, ascorbic acid, carotenoids, saponins, elements. The quantitative content of flavonoids was determined by spectrophotometric method in the differential version, the analytical wavelength 415 nm was determined, the percentage content of flavonoids in terms of rutin was calculated. The total flavonoid content was 3.28–4.94%. The content of phenylpropanoids (3.32–3.67%), tannins (4.36–5.12%), anthocyanins (0.54–0.80%), triterpene saponins (0.95–1.08%), amino acids (6.24–6.42%), carotenoids (0.08–0.09%) was determined spectrophotometrically; by titrimetric methods – ascorbic acid (0.30–0.38%), organic acids (1.75–1.90%). 8 macronutrients (calcium 10800 mg/kg, potassium 24000 mg/kg, magnesium 3600 mg/kg), 20 micronutrients (manganese 53 mg/kg, zinc 2 mg/kg, selenium 0.13 mg/kg) were identified. The standards for the content of flavonoids in the collection are not less than 3.0%, the sum of phenylpropanoids is not less than 2.5%, total ash is not more than 11%, ash insoluble in hydrochloric acid is not more than 3.5%. The established parameters determine the quality of collection of angioprotective action.