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Arbutin is the main active ingredient in many herbal medicinal products that have diuretic, antimicrobial, bactericidal, and antioxidant effects. Many of these products are mixtures of different herbal substances. Therefore, the approaches to quality control of HMPs can vary significantly. The aim of the study was to compare arbutin assay procedures used in quality control of arbutin-containing products. Materials and methods. Samples of the following HMPs were used in the study: monocomponent Bearberry Leaf and multicomponent Brusniver® (herbal mixture, powder). The test methods used were titrimetry, ultraviolet-visible spectrophotometry, and high-performance liquid chromatography (HPLC). Results. The authors compared five arbutin assay procedures described in the monographs and product files for arbutin-containing HMPs. Conclusions. It has been established that the analysed procedures cannot be used interchangeably as equivalent test methods; the limits for arbutin have to be established for each specific procedure. Iodometric titration is the most labour- and time-consuming method, and the determined titration endpoint is a subjective assessment. Spectrophotometric methods do not require the use of an arbutin reference standard, but they can give overestimated results as compared to the HPLC and titrimetry methods. HPLC methods are more selective, but they require the use of reference standards. The recommended test methods for HMP quality control are HPLC and visible spectrophotometry; the titrimetric method is recommended for replacement.

Specialists in pharmacognosy are facing an important task of improving quality control methods for combination herbal medicinal products in order to enable reliable assessment of the content of active substances that are responsible for the drug’s pharmacological effect.The aim of the study was to investigate the possibility of using the European Pharmacopoeia method to determine the total content of anthracene derivatives in the antihaemorrhoidal medicinal herb mixture Proctophytol® and to propose limit values for the total content of anthracene derivatives.Materials and methods: individual mixture components containing anthracene derivatives, such as senna leaves and frangula bark, as well as model mixtures containing these individual components in a 1:1 ratio, and a model mixture imitating Proctophytol® were used in the study. The determination of the anthracene derivatives content was carried out using spectrophotometry.Results: it was demonstrated that the European Pharmacopoeia method could be used to assess the quality of Proctophytol® in terms of anthracene derivatives total content. The spectrophotometric method described in the European Pharmacopoeia has advantages over the methods described in manufacturer specifications for Russian products, because it allows for thorough extraction of the active substances and is standardized for anthracene derivatives.Conclusions: the European Pharmacopoeia method was adjusted to determine anthracene derivatives in the medicinal herb mixture Proctophytol®. It was proposed to use 70% ethanol instead of 70% methanol as extraction solvent. The authors identified optimum sample weights and test solution dilutions, and calculated and verified the limit for anthracene derivatives content—“Not less than 1.9%”. The adjusted method can be recommended for inclusion in the monographs of the State Pharmacopoeia of the Russian Federation for medicinal herb mixtures similar to Proctophytol®.

The process of harmonisation of Russian and foreign approaches and requirements in the field of medicines quality assurance calls for revision of quality control procedures included in various regulations and guidelines. The monograph FS.2.5.0062.18 “Hawthorn flowers” of the State Pharmacopoeia of the Russian Federation XIV edition includes a test procedure for determination of flavonoids by a chromatospectrophotometric method. This procedure does not take into account current scientific capabilities and has a number of shortcomings, therefore it was necessary to revise the existing test procedure and develop a new approach to the standardisation of the hawthorn flower herbal substance.The objectiveof the studywas to develop an assay method for standardisation and evaluation of hawthorn flower using high performance liquid chromatography (HPLC).Materials and methods:the study was performed using samples of hawthorn flowers by Russian manufacturers. Quercetin (USP RS) and Hyperoside (HWI, primary standard) were used as the reference standards. The HPLC analysis was performed using an Infinity II 1260 DAD LC system (Agilent), and the UV spectra were recorded on a Cary 100 Varian spectrophotometer. A TLC Visualizer (CAMAG) was used to obtain digital images of thin layer chromatography plates.Results:the authors developed an HPLC test procedure for quantitative determination of total flavonoids, expressed as hyperoside, in hawthorn flowers. The developed procedure gives reliable and reproducible results and is characterised by high sensitivity and selectivity. The results of quantitative determination of the total flavonoid content in hawthorn flowers were used to propose the standard for the total content of flavonoids, expressed as hyperoside, of “not less than 0.5%”.Conclusions:the developed assay method for determination of active pharmaceutical ingredients in hawthorn flower products by HPLC can be recommended for inclusion into the Assay part of the “Hawthorn Flowers” monograph of the State Pharmacopoeia of the Russian Federation.

The use of assay methods with different test conditions for determination of anthracene derivatives in herbal substances and herbal medicinal products requires adjustment of the established limits for total anthracene derivatives content based on the test method used.The aimof the study was to compare different pharmacopoeial methods of quantitative determination of anthracene derivatives, and established limits for the active substance content, and to analyse the possibility of adjusting the limits based on the test method used.Materials and methods: the total content of anthracene derivatives was measured in the samples of frangula bark (fragmented bark and powder) and senna leaves (fragmented leaves and powder) using the test methods described in the State Pharmacopoeia of the Russian Federation (XI and XIII editions), and the European Pharmacopoeia.Results:the analysis of Russian and foreign pharmacopoeial requirements for determination of anthracene derivatives in laxative herbal medicinal products demonstrated differences in extraction solvents, extraction conditions, and calculation methods used. The experiments showed that the optimal extraction solvent was 70 % alcohol solutions, and that an indirect cobaltic chloride reference standard should be replaced by specific absorbance of glucofrangulin A and sennoside B. It was shown that the limits for total anthracene derivatives content should be chosen based on the extraction conditions used.Conclusions:comparative theoretical research and experimental studies helped to determine optimal assay conditions and respective limits for total anthracene derivatives content to be used in quality control of herbal substances and herbal medicinal products.