RESEARCH ON DETERMINATION OF QUANTITATIVE QUERCETIN CONTENT IN COMBINED GEL FOR TREATMENT OF RADIATION SKIN DAMAGE

Abstract

Introduction. Increased interest in phytotherapy can be explained mainly by its relative safety and effectiveness, as well as the lower cost of drugs derived from herbal raw materials, compared to synthetic remedies. With this in mind, as a result of experimental research, we have developed a technology for complex processing of large grass stonecrops in order to obtain juice and aqueous extract from the pomace after squeezing the juice and investigated their quality indicators.

The aim of the study – to conduct experimental research to develop methods for determining the quantitative content of quercetin in the combined gel under the conditional name “Biosedum Plus” for the treatment of radiation damage to the skin.

Research Methods. The objects of the study were model samples of the combined gel. TLC plates with a layer of silica gel and a fluorescent indicator F₂₅₄ (s. HX04954354, Merk, Germany), a standard sample of quercetin, Evolution 60s spectrophotometer (Thermo Fisher Scientific, USA), analytical scales “AXIS” (Poland), measuring instruments of class A and reagents that meet the requirements of the State Pharmacopoeia of Ukraine (SPhU) were used.

Results and Discussion. An intensely expressed maximum absorption of the substance at a wavelength of 438 nm after the reaction with boric acid was chosen to develop the method of quantitative determination of quercetin in the studied gel by the method of absorption spectrophotometry in the visible region. The specificity of the technique was proved by the formation of a coloured complex of quercetin with boric acid in the presence of a mixture of formic and acetic acids. The precision of the experimental results was characterized by low standard deviation in the studied range of quercetin concentrations (RSD = 0.46 %), and the systematic error was 0.01 %, the correlation coefficient of the proposed method r = 0.9995. When studying the robustness of the method, it was found that the stability of the absorption of solutions over time is observed after 30 minutes and the solutions are stable for 60 minutes.

Conclusions. A method of spectrophotometric quantitative determination of quercetin in a gel after the reaction of formation of a complex with boric acid at a wavelength of 438 nm was developed. According to such validation characteristics as linearity, precision, accuracy and robustness, the method is correct (using eligibility criteria for content tolerances + 5.0 %).