Spectrophotometric and Chromatographic Assessment of Total Polyphenol and Flavonoid Content in Rhododendron tomentosum Extracts and Their Antioxidant and Antimicrobial Activity.

In the literature, the chemical composition of Rhododendron tomentosum is mainly represented by the study of isoprenoid compounds of essential oil. In contrast, the study of the content of flavonoids will contribute to the expansion of pharmacological action and the use of the medicinal plant for medical purposes. The paper deals with the technology of extracts from Rh. tomentosum shoots using ethanol of various concentrations and purified water as an extractant. Extracts from Rh. tomentosum were obtained by a modified method that combined the effects of ultrasound and temperature to maximize the extraction of biologically active substances from the raw material. Using the method of high-performance thin-layer chromatography in a system with solvents ethyl acetate/formic acid/water (15:1:1), the following substances have been separated and identified in all the extracts obtained: rutin, hyperoside, quercetin, and chlorogenic acid. The total polyphenol content (TPC) and total flavonoid content (TFC) were estimated using spectrophotometric methods involving the Folin-Ciocalteu (F-C) reagent and the complexation reaction with aluminum chloride, respectively. A correlation analysis was conducted between antioxidant activity and the polyphenolic substance content. Following the DPPH assay, regression analysis shows that phenolic compounds contribute to about 80% (r2 = 0.8028, p < 0.05) of radical scavenging properties in the extract of Rh. tomentosum. The extract of Rh. tomentosum obtained by ethanol 30% inhibits the growth of test cultures of microorganisms in 1:1 and 1:2 dilutions of the clinical strains #211 Staphylococcus aureus and #222 Enterococcus spp. and the reference strain Pseudomonas aeruginosa ATCC 10145.

Investigation of the Rheological Properties of Ointment Bases as a Justification of the Ointment Composition for Herpes Treatment

Objectives: Combinatorial drugs are among the leading pharmacotherapeutic agents, including those used for the treatment of herpetic infections, which require complex treatment. We have developed a soft dosage form of ointment, which includes acyclovir and miramistin, which have antimicrobial, anti-inflammatory, and local immunoadjuvant activity. The study aimed to investigate the rheological properties of ointment bases in order to substantiate the composition of a soft dosage form with antiviral effect using the active ingredients miramistin and acyclovir. Materials and Methods: The object of the study was to determine the heterogeneous and homogeneous composition models of the bases made using a wide range of excipients. Structural and mechanical studies were performed using the "Rheolab QC" rotary viscometer by Anton Paar (Austria) with coaxial cylinders CC27/S-SN29766. The rheological parameters were investigated at a temperature of 25°C±0.5°C. The samples were thermostated using a thermostat MLM U15c. The batch of sample weighing about 15.0±0.5 g was placed in the container of an external stationary cylinder. The required temperature of the experiment was set and the thermostating time was 20 min. The device is equipped with RheoPlus 32 V3.62 software. Results: The rheological behavior of the model compositions was analyzed in terms of indicators, such as yield strength, hysteresis square, coefficients of dynamic flow, and mechanical stability. It was found that all samples have a non-Newtonian pseudoplastic type of flow. The model of spreading optimums was used to evaluate consumer properties. According to the rheological parameters, it is advisable to use the sample based on paraffin and vaseline oil for further research. Conclusion: The findings from this study will be relevant in the development of the soft dosage form for the treatment of herpes viral diseases.