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Ascorbic acid (vitamin C) is involved in many vital biochemical processes in the human body. Rose hips are a natural source of ascorbic acid. Rose hips are used in decoctions and many vitamin herbal teas. Russian compendial methods for the quantitative determination of ascorbic acid have certain limitations precluding its objective measurement in herbal drugs, herbal drug preparations, and herbal medicinal products.The aim of the study was to develop an analytical procedure for the quantitative determination of ascorbic acid in herbal drugs, herbal medicinal preparations, and herbal medicinal products using high performance liquid chromatography (HPLC).Materials and methods. The study involved two herbal medicinal products, Rose Hips (rose hips) and Vitamin Herbal Tea 2 (rose hips and rowan fruits), and reference standards for ascorbic acid, rutoside, quercetin, gallic acid, caffeic acid, chlorogenic acid, luteolin-7-glucoside, citric acid, DL-malic acid, thiamine, and pyridoxine hydrochloride. The authors used a 1260 Infinity II chromatograph with a diode array detector by Agilent and an Inertsil ODS-3 chromatographic column (250 mm × 4.6 mm, 5 µm) by GL Sciences. The HPLC system was operated in gradient elution mode, and the detector was set at 244 nm.Results. Ascorbic acid content in herbal drugs, herbal medicinal preparations, and herbal medicinal products can be determined by HPLC. Adequate sample preparation and chromatography conditions allow for inhibiting ascorbic acid oxidation in aqueous solutions for a period sufficient to complete testing (not less than 8 h).Conclusions. The authors developed a highly sensitive and selective HPLC procedure for the quantitative determination of ascorbic acid intended for the standardisation of herbal drugs, herbal medicinal preparations, and herbal medicinal products. The procedure is worthy of inclusion in the Rose Hips and Vitamin Herbal Tea 2 monographs of the State Pharmacopoeia of the Russian Federation. Switching to HPLC should not require lowering the limit for ascorbic acid (not less than 0.2%) established in the Rose Hips and Vitamin Herbal Tea 2 monographs for the titration method. The ascorbic acid content was below this limit in the vast majority of study samples. However, this discrepancy may be explained by the presence of dog rose (Rosa canina) species low in vitamin C, which should normally be used only as choleretics.

When used to quantify alkaloids in thermopsis dry extract, acidimetric titration has several limitations, including insufficient specificity of the method and arbitrary selection of a titration endpoint. Different parts of the Thermopsis lanceolata plant produce alkaloids in different proportions: the herb is rich in thermopsine, whereas the seeds are rich in cytisine. Since thermopsine and cytisine have different pharmacological effects, it is important to identify and quantify individual alkaloids in thermopsis dry extract.The aim of the study was to develop and validate an analytical procedure for identifying and quantifying total alkaloids in thermopsis dry extract by high-performance thin-layer chromatography (HPTLC) with densitometric detection.Materials and methods. The study included samples from two pilot-scale batches of thermopsis dry extract and reference standards for cytisine and thermopsine. The authors used Merck HPTLС Silica Gel 60 F254 20×10 cm plates for chromatographic separation and analysed the results with a CAMAG® TLC Scanner 4 densitometer and the winCATS software.Results. The authors identified thermopsis dry extract using HPTLC separation followed by spectrodensitometry. The alkaloid-specific solution applied to chromatography plates helped to identify the three most abundant and four minor alkaloids of thermopsis. The most abundant alkaloids were thermopsine, cytisine, and an unidentified alkaloid with a retention factor of approximately 0.2. These three alkaloids accounted for almost 80% of the total alkaloid content of the dry extract. The authors quantified cytisine, thermopsine, and total alkaloids expressed as thermopsine.Conclusions. The authors developed and validated an analytical procedure for identifying and quantifying total alkaloids in thermopsis dry extract. This procedure offers the possibility of reducing the analysis time from 4–5 hours to 2–2.5 hours.

Currently, there is an increase in pre- and post-approval testing of medicinal products containing diosmin and hence a need to unify approaches to standardisation of this group of pharmaceuticals. Moreover, the State Pharmacopoeia of the Russian Federation lacks a monograph for these products.The aim of the study was to determine an approach to standardisation of medicinal products containing diosmin.Materials and methods: the study analysed scientific publications, as well as monographs of leading foreign pharmacopoeias. Experimental work was carried out using samples of diosmin-containing pharmaceuticals in the form of 500 and 1000 mg film-coated tablets produced by Russian and foreign manufacturers. The study involved high performance liquid chromatography with UV detection using an Agilent 1260 Infinity II liquid chromatography system with a diode array detector. The following reference standards were used: a diosmin RS, USP grade; a hesperidin CRS, Ph. Eur. Grade; and a diosmin CRS for testing chromatography system suitability for identification of impurities A, B, C, D, E, and F, Ph. Eur. grade.Results: the authors reviewed quality requirements for pharmaceutical products containing diosmin and analysed experimental data obtained during pre- and post-approval testing of Russian and foreign medicines. The comparison of regulatory documents for registered diosmin-containing medicinal products showed a difference in approaches to assessing the contents of related substances and active pharmaceutical ingredients. Having analysed the literature, experimental data and regulatory requirements for standardisation of diosmin-containing pharmaceuticals, the authors recommended an approach to standardisation. According to the approach, concomitant flavonoids (hesperidin, isorchoifolin, linarin, and diosmetin) contributing to the pharmacological activity of a medicinal product are specified as part of Assay, and process-related by-products (impurities A and D) are specified and evaluated as part of Related substances tests.Conclusion: the authors propose to evaluate the contents of concomitant flavonoids (hesperidin, isorchoifolin, linarin, diosmetin) under Assay and to specify impurities A and D, as well as single unidentified impurities and total amount of impurities under Related substances.

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.

A differential quantitative determination method for tannins in herbal raw materials and medicines is described. The main feature of the method is the ability to vary the analysis conditions (reference standards, analytical wavelength, sample weight) considering the structural class of the extracted tannins.