Development of the composition of aqueous extract of Lespedeza bicolor and gel with extract and mangifierin

Abstract

The aim of the work: research on the development and standardization of an aqueous extract of the aerial part of Lespedeza bicolor and the study of pharmacotechnological parameters of a gel with the extract and mangiferin. Materials and methods: in the studies on obtaining an aqueous extract, the aerial part of Lespedeza bicolor, harvested in the Botanical Garden of the Ivan Franko National University of Lviv (Lviv, Ukraine) in the flowering phase, was used. Identification and quantitative content of biologically active compounds in the experimental samples of the extracts were carried out by chemical reactions, thin-layer chromatography and absorption spectrophotometry. The results obtained were used to standardize the selected aqueous extract of Lespedeza (AEL). In the development of the gel, AEL, mangiferin (China, X’ian Pincredit Bio-Tech Co., Ltd. QC004) and excipients of domestic and foreign production were used. The studies used physicochemical (pH value) and pharmacotechnological research methods (thermo- and colloidal stability, dispersion analysis, dialysis method through a semipermeable membrane). Results. The conditions for obtaining AEL were experimentally substantiated. It was shown that the use of threestage remaceration with infusion for 60 minutes at a temperature of 90–100 °C ensures maximum extraction of polyphenolic compounds. The TLC method identified the presence of rutin, quercetin, chlorogenic and caffeic acids, tannins and substances of polysaccharide structure in the extract. Methods for quantitative determination of polyphenolic compounds and flavonoids by absorption spectrophotometry were developed. Based on the results of microscopic analysis, study of the osmotic activity of the base and the dynamics of mangiferin release, the composition of a dermatological gel was proposed, containing AEL, mangiferin, PEO-400, ethanol 96 %, corn oil, tween 80, carbopol, trometamol, purified water. Conclusions. The conditions for obtaining and standardizing the aqueous extract of Lespedeza bicolor were substantiated. The composition of the gel with mangiferin and AEL was proposed. It was shown that the introduction of 20 % PEO-400, 10 % ethanol 96 % and 1 % tween-80 into the gel base ensures its absorption capacity and increases the rate of mangiferin release