Introduction. Myrtle (Myrtus communis L.) is widespread in the Mediterranean region and is cultivated in many countries of the world, including the Russian Federation. There are several varieties within the Myrtus communis L. species. The most well-known varieties are common myrtle (M. communis L.) and small-leaved myrtle (M. communis var. microphylla Willk.).

Aim. A comparative analysis of the component composition of common myrtle (Myrtus communis L.) and small-leaved myrtle (Myrtus communis var. microphylla Willk.) in extracts of varying polarity (petroleum ether, hexane, methanol) to identify chemotaxonomic markers and evaluate the antiplatelet and antioxidant activity of aqueous extracts from the leaves of Myrtus communis L. and Myrtus communis var. microphylla Willk.

Materials and methods. The subjects of the study were dried leaves of M. communis and M. communis var. microphylla, collected in 2024–2025 at the educational experimental farm (limonarium) of the Ufa Forest Technical College. To analyze the chemical composition, extraction was performed using various solvents: petroleum ether, hexane, and methanol. The component composition was analyzed by gas chromatography-mass spectrometry (GC-MS) on an Agilent 8890GC chromatograph coupled with an Agilent 5977B mass spectrometer. For pharmacological studies, infusions were prepared according to pharmacopoeial methods. Pharmacological activity was studied using hemostasis models (platelet aggregation, APTT) and antioxidant activity (chemiluminescence in models of ROS generation, lipid peroxidation, and macrophage activity).

Results and discussion. In the extracts of M. communis and M. communis var. microphylla, between 10 and 20 components were identified. It was established that the content of myrtenyl acetate is characteristic only for M. communis var. microphylla in all studied extracts: in hexane (12.78 %), methanol (5.59 %), and petroleum ether (2.44 %). M. communis and M. communis var. microphylla contain β-sitosterol (10–12 % in hexane), vitamin E (3–6 %), and eicosane (6–13 %). Pharmacological studies revealed moderate anti-aggregant activity of M. communis and M. communis var. microphylla: an increase in the latency period by 5.2–6.5 % and a decrease in aggregation rate by 8.7–10.3 %. M. communis var. microphylla exhibited more pronounced antioxidant activity (reduction of lipid peroxidation by 12.1–12.4 % for M. communis var. microphylla, and by 6.2–10.4 % for M. communis).

Conclusion. The obtained data expand the understanding of intraspecific variability of the species M. communis and can be used for the development of regulatory documentation on raw materials from various varieties of myrtle, as well as for the creation of phytopreparations with antiplatelet and antioxidant properties.

Introduction. Heracleum sosnowskyi Manden. is a dangerous invasive species containing phototoxic furanocoumarins (FCs). Despite their known cytotoxicity, the antimicrobial potential of FCs has been insufficiently studied, and the contribution of FCs to the overall effect of plant extracts, taking into account technological parameters, has not been established.

Aim. A comprehensive assessment of the contribution of furanocoumarins to the antimicrobial activity of extraction products from Heracleum sosnowskyi Manden. herb, depending on the nature of the extractant, temperature, and degree of purification.

Materials and methods. Ten extraction products were obtained from raw materials collected in Perm Krai, grouped according to the principle "from native raw materials to individual compounds": juice, hexane extracts (with and without heating), petroleum ether extract, alcohol extracts from defatted raw materials, a total FC fraction, and three enriched fractions (xanthotoxin + psoralen, angelicin + bergapten, angelicin + psoralen + bergapten). The composition was analyzed by TLC and HPLC. Antimicrobial activity was determined against Staphylococcus aureus, Escherichia coli, and Candida albicans using the microdilution method.

Results and discussion. HPLC analysis revealed significant differences in the FC profiles. The juice contained a minimum of FCs (~6 %) and was inactive (MIC > 5000 μg/mL). Alcohol extracts from defatted raw materials (FC content 34–60 %) showed low activity (MIC 2500–5000 μg/mL). Lipophilic extracts (hexane, petroleum ether) were characterized by high FC content (80–98 %) and moderate activity (MIC 625–2500 μg/mL); heating during hexane extraction increased the proportion of angelicin and activity against Escherichia coli. The total FC fraction (96 % FC, predominance of angelicin) exhibited high activity (MIC 625–1250 μg/mL). The enriched fractions demonstrated the highest efficacy (MIC 62.5–250 μg/mL), with the three-component mixture (angelicin + psoralen + bergapten) outperforming binary mixtures, indicating synergism.

Conclusion. Furanocoumarins are the main carriers of antimicrobial activity in Heracleum sosnowskyi Manden. extracts. Polar components (pigments) make a minor contribution. Extraction efficiency depends on the method: heating with hexane and the use of petroleum ether (a cost-effective alternative) ensure maximum recovery of active FCs. The purified total FC fraction and enriched fractions, especially the three-component one, represent promising candidates for further development of antimicrobial drugs.

Introduction. The indolinone derivative 2-[2-[(5RS)-5-(hydroxymethyl)-3-methyl-1,3-oxazolidin-2-ylidene]-2-cyanoethylidene]-1H-indol-3(2H)-one (hereinafter referred to as GRS) is a novel soluble guanylate cyclase stimulator and serves as the active pharmaceutical ingredient in the new antithrombotic drug, capsules 20 mg. In pharmaceutical development and industrial manufacturing of medicinal products, multistage quality control is a determining factor for their efficacy and safety. Therefore, the development and validation of rapid and precise analytical methods is an important scientific and practical task.

Aim. To develop and validate a method for the quantitative determination of the active substance (GRS) in the drug product (capsules, 20 mg) using high-performance liquid chromatography with a diode array detector.

Materials and methods. The study objects included the drug containing GRS, (capsules, 20 mg), excipients used in its manufacturing, and the GRS API (powder). Chromatographic conditions were as follows: Kromasil C18 chromatographic column (250 × 4.6 mm, 5 μm); column oven temperature 40 °C; detection wavelength 372 nm; mobile phase A – acetate buffer (pH 4.0); mobile phase B – methanol. Gradient elution mode was performed over 17 min.

Results and discussion. The developed method has been validated according to the following parameters: specificity, linearity within the analytical range, accuracy, precision, and robustness.

Conclusion. The developed method of high-performance liquid chromatography for the quantitative determination of the active substance GRS in the drug product (capsules, 20 mg), has acceptable validation characteristics and is rapid and simple in terms of sample preparation, which allows it to be used in routine analysis for quality control during production.

Introduction. Combination products of linagliptin and empagliflozin are widely used for the treatment of type 2 diabetes mellitus. Both active substances belong to class III of the Biopharmaceutical Classification System (BCS), characterized by high solubility and low permeability. In the development of generic medicinal products, demonstration of therapeutic equivalence is critical; for this purpose, a comparative in vitro dissolution kinetics test is conducted within the framework of a biowaiver. However, for class III drugs, permeability is the rate-limiting step of absorption, necessitating the use of additional methodologies for its assessment.

Aim. Comparative study of dissolution and permeability profiles of linagliptin and empagliflozin from film-coated tablets of a test combination product and a reference product using the Dissoflux™ methodology to substantiate the applicability of this approach in the assessment of biopharmaceutical equivalence.

Materials and methods. The study objects were film-coated tablets of the test product (combination of linagliptin 2.5 mg and empagliflozin 10 mg) and a reference product of identical dosage. The comparative dissolution kinetics test (CDKT) was performed using a paddle apparatus (TrustE-8 basic, Electrolab, India) at 50 rpm in media with pH 1.2, 4.5 and 6.8 (volume 500 mL). Permeability studies were conducted using the Dissoflux™ system (Electrolab, India) in pH 6.8 medium (donor) and buffer solution with 0.05 % Tween 20 (acceptor, pH 7.4). Quantitative determination of the active substances was performed by HPLC-UV with gradient elution on a Symmetry® C18 column (Waters Corporation, USA).

Results and discussion. The developed HPLC-UV method demonstrated high reproducibility and accuracy. In media with pH 1.2, 4.5 and 6.8, the release of active substances from both dosage forms exceeded 85 % by 15 minutes, indicating equivalence of dissolution profiles. The permeability test results using the Dissoflux™ methodology demonstrated comparable accumulation profiles of both active substances in the acceptor chamber. The Flux ratio for linagliptin was 92.13 %, and for empagliflozin 100.31 %.

Conclusion. The comparability of dissolution profiles of linagliptin and empagliflozin from the test and reference products in all three media was demonstrated. Pilot data from the permeability test in vitro using the Dissoflux™ system demonstrated the potential of this methodology as an ancillary tool for biopharmaceutical evaluation during drug development, although final conclusions require statistical confirmation based on no fewer than three independent replicates.