Herbal drugs and herbal medicinal products remain of interest to Russian researchers both in terms of the development, efficacy, and safety of medicines, and in terms of the research methodology applicable to these medicine, as well as the use of new analytical methods expanding the boundaries of contemporary science and medicine. In this interview, Vladimir G. Luzhanin (Candidate of Sciences, Associate Professor, Rector of the Perm State Pharmaceutical Academy), Vladimir A. Kurkin (Doctor of Pharmaceutical Sciences, Full Professor, Chairman of the Department of Pharmacognosy with Botany and the Basics of Phytotherapy, Samara State Medical University), and Irina V. Gravel (Doctor of Pharmaceutical Sciences, Full Professor, Professor of the I.M. Sechenov First Moscow State Medical University) share their views on the application potential and future quality assessment of herbal medicines.

According to the authors’ analysis of regulatory documents for homoeopathic medicines of Virginian witch hazel (Hamamelis virginiana L.), there is a need to transform quality assessment approaches and to unify analytical procedures for identification and assay tests.

The aim of the study was to determine approaches to identification and assay of homoeopathic mother tinctures of Virginian witch hazel leaves and bark and medicinal products based on the tinctures.

Materials and methods: in order to select quality evaluation procedures, the authors analysed scientific literature, Russian and foreign pharmacopoeias and regulatory documentation regarding homoeopathic medicines of Witch hazel. The authors performed practical evaluation of the selected procedures based on thin-layer chromatography, spectrophotometry, qualitative reactions, and titrimetry, using samples of homoeopathic mother tinctures of Witch hazel leaves and bark, as well as corresponding homoeopathic medicinal products in various dosage forms.

Results: the authors proposed identification and assay procedures for the studied active pharmaceutical ingredients (APIs) and homoeopathic medicinal products and prepared the drafts of pharmacopoeial monographs Hamamelis virginiana e foliis (Hamamelis, Folium) homoeopathic mother tincture and Hamamelis virginiana (Hamamelis) homoeopathic mother tincture. The unified procedures were included in the draft monographs for homoeopathic medicinal products Hamamelis, homoeopathic drops; Hamamelis D1, homoeopathic ointment; Hamamelis, folium D1, homoeopathic ointment; Hamamelis virginiana e foliis D1, rectal homoeopathic suppositories.

Conclusions: the developed procedures are compatible with the principle of holistic, end-to-end standardisation, as they make it possible to carry out identification tests and assays using the same class of biologically active compounds throughout the whole range of homoeopathic medicines from APIs to finished products. The authors proposed the methodology for assessing homoeopathic medicinal products’ quality, taking into account the degree of dilution of the homoeopathic tinctures used.

Essential oils are a common group of bioactive compounds, yet their standardisation remains relevant.

The aim of the study was to compare pharmacopoeial approaches to the standardisation of herbal drugs and herbal drug preparations containing essential oils using the examples of the State Pharmacopoeia of the Russian Federation (14th edition) and the European Pharmacopoeia (10th edition).

The advantages of Russian pharmacopoeial approaches include testing for additional groups of bioactive compounds that contribute significantly to the pharmacotherapeutic effect of extractive preparations. The main compendial method for the component analysis of essential oils is gas chromatography with a flame ionisation detector; its limitations include the need for a considerable number of reference standards. The essential oil content limits established by the two pharmacopoeias for the same types of herbal drugs are not the same. The differences may be associated with differences in sample preparation conditions and analytical procedures for the determination of essential oil content, as well as with growth conditions of plants used to obtain data sets for the standardisation of this quality attribute. As a particular medicinal plant may have several chemotypes differing in the essential oil composition, it seems relevant to consider this composition in the studies of pharmacological activity of herbal drugs associated with essential oils.

Brown seaweeds (Laminariaceae) vary considerably in the content of toxic and essential elements; these variations depend on the taxonomic group and geographical factors. Seaweeds are extensively used in the food industry and widely applied in medicine for both humans and animals. Therefore, it is relevant to examine the correlation between the elemental composition and the geographical origin of kelp thalli obtained from different sources.

The aim of the study was to collect, collate, and analyse primary and secondary data on the accumulation of essential, toxic and potentially carcinogenic elements, including iodine, in the thalli of brown seaweeds (Laminariaceae).

Materials and methods. This study investigated the concentrations of 17 elements in Laminaria spp. (Al, As, Cd, Cr, Co, Cu, Fe, Hg, Mn, Mo, Ni, Se, Pb, Sr, V, Zn, and I). Experiments were conducted on an Agilent 7900 inductively coupled plasma mass spectrometer. The authors studied publications on the elemental composition of brown seaweeds (Laminariaceae) using literature search and data analysis methods.

Results. This article reflects the updated classification of brown seaweeds (Laminariaceae) and summarises information about the mechanisms by which iodine and other elements accumulate in the thallus. The authors established species-specific variations in the order of element uptake and in the accumulation of elemental toxicants. The mutual influence of elements on their accumulation in brown seaweeds (Laminariaceae) was evaluated using Spearman’s rank correlation coefficients.

Conclusions. The study results can inform the implementation of a risk-based quality control strategy for herbal medicinal products aimed at reducing human exposure to toxic elements. The authors suggest that the upper limit of iodine content in kelp-based food products should be standardised.

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 chromato-graphic 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.

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.

Currently, there is an increase in preand 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 preand 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.

Kelp can accumulate large quantities of arsenic compounds even in the absence of considerable environmental pollution. A substantial difference in toxicity between organic and inorganic arsenic compounds makes the form of arsenic relevant for the risk assessment of consuming kelp thalli and kelp-based products.

The aim of the study was to develop an analytical procedure for the selective quantification of organic and inorganic arsenic in kelp thalli by inductively coupled plasma mass spectrometry and solid-phase extraction without scheduled precursors.

Materials and methods. The authors studied samples of Laminaria saccharina and Laminaria japonica, spiking mixtures of chemical compounds containing arsenic in different oxidation states, and bioactive dietary supplements based on kelp thalli. Solid-phase extraction was performed using Maxi-Clean SAX cartridges. The arsenic content was determined using an Agilent 7900 inductively coupled plasma mass spectrometer.

Results. Microwave-assisted extraction with deionised water ensures 91% recovery of arsenic-containing compounds from kelp thalli, and the addition of hydrogen peroxide to the extractant provides complete extraction. Solid-phase extraction with an eluent based on 3% H2O2 can extract the organic fraction from a mixture of organic and inorganic arsenic compounds without washing the inorganic fraction off the cartridge.

Conclusions. The authors offer an effective analytical procedure for the selective quantification of organic and inorganic arsenic in kelp thalli and kelp-based products. This procedure allows for the isolation of arsenic-containing compounds from the organic matrix of kelp with 3% hydrogen peroxide. Solid-phase extraction with this extractant can effectively separate organic and inorganic fractions without prior neutralisation of the test solution.

Sea buckthorn fruits are a pharmacopoeial raw material used to produce sea buckthorn oil. Other parts of the plant (bark, leaves, and shoots) are objects of research aiming to expand the raw material base and use limited natural resources rationally. Sea buckthorn leaves are rich in biologically active compounds, including flavonoids.

The aim of the study was to develop and validate an analytical procedure for the quantification of flavonoids in sea buckthorn leaves using spectrophotometry in the visible spectral region.

Materials and methods. The study focused on dried leaves of sea buckthorn harvested in the Voronezh region in 2022. These leaves were collected from wild plants at three phenological stages: fruit setting (I), single fruit ripening (II), and mass fruit ripening (III). To quantify flavonoids in sea buckthorn leaves, the authors used an analytical procedure based on measuring the absorbance of a solution containing products of the reaction between flavonoids and aluminium chloride.

Results. The absorption maximum of the complex between the alcohol extract of sea buckthorn leaves and aluminium chloride was observed at 402±2 nm; the wavelength corresponds to the absorption maximum of luteolin. The optimal extraction conditions included 70% ethanol as the extraction solvent, a raw material to solvent ratio of 1:150, a particle size of 0.5 mm, and a single extraction cycle of 45 min.

Conclusions. The authors developed and validated a spectrophotometric procedure for the quantification of total flavonoids, expressed as luteolin, in sea buckthorn leaves. The procedure can be used to standardise this herbal drug. As observed in the study, the total flavonoid content was the highest (up to 1.5%) in the raw material at phenological stage I (collected in mid-June) and gradually decreased through mid-July to the end of August. Since sea buckthorn is the source of sea buckthorn oil and the early collection of leaves may decrease its value or lead to non-compliance with pharmacopoeial requirements, the recommended time for harvesting leaves should coincide with that for harvesting fruits. Collected at this stage of growth and development, sea buckthorn leaves still contain sufficient flavonoids (up to 0.8%) and can be used as an individual herbal drug.

The World Health Organisation develops and promotes international standards for pharmaceutical products, in support of efforts to increase access to quality-assured medicines for all, and to safeguard patients from substandard and falsified medicines. The International Pharmacopoeia is a key output of this work. Its focus, processes to establish texts for inclusion or revision, response to COVID-19 and the collaboration with other Pharmacopoeias shall be discussed in this review. Pharmacopoeias provide public standards (written norms as well as physical reference standards), which ensure the quality of medicines by defining the attributes that are essential to their safety and efficacy. They consist of analytical methods to test for the identity, purity and content of pharmaceutical products, together with acceptance criteria to evaluate test results, and information about storage, labelling and production. Pharmacopoeias greatly facilitate the development of multi-source medicines (generics) by defining minimum quality standards that a group of medicines must meet in order to be considered of commensurate safety, quality and effectiveness as the originator product(s). The added value of The International Pharmacopoeia lies in its focus on monographs of particular relevance to lowand middle-income countries which may not have sufficient resources to develop national pharmacopoeias. In a globalised world, where medicines and health products are frequently sourced from several countries with differing regulatory standards and requirements, and when the response to Public Health Emergencies of International Concern, like the COVID-19 pandemic, necessitates swift and equitable access to urgently needed quality-assured therapeutics, such a resource is indispensable.