The manufacture of ethanol-free propolis solutions offers a broader application. A few trials with Lithuanian propolis have been conducted. The aims of the study are to manufacture propolis water and water-free solutions and evaluate the quality and antimicrobial activity of these solutions. The studied solutions containing 2.5%, 5%, and 10% propolis are prepared. As solvents, purified water, 70% v/v ethanol, 96.3% v/v ethanol, propylene glycol, and their systems were used. Determination of total levels of phenolic compounds (FAE mg/g) is based on colour oxidation-reduction reaction using Folin-Ciocalteu reagent under alkaline conditions and performed at 765 nm wavelength using UV spectrophotometer. The highest content of phenolic compounds was determined in solutions containing 10% propolis extracts, and the lowest amounts in 2.5% propolis extracts. The water extracted the lowest amount of phenolic compounds from crude propolis, ethanol extracted the highest amount, and propylene glycol ranked the middle position. It is determined that technological parameters (stirring, temperature) contribute to content of phenolic compounds. During microbiological study, MICs were determined. The studies showed that water extracted propolis solutions and solvents mixture did not inhibit the growth of the studied microorganisms, and propolis solutions in propylene glycol were found to have antimicrobial activity.

The aim of the study was to analyze phenolic acids in Lithuanian propolis and to compare it with the composition of propolis in neighboring countries (Latvia and Poland) according to the predominant flora in the collecting places. The study was also aimed at the evaluation of the effect of the layer thickness (mm) of the harvested propolis on the quality of the raw material in determining the amount of phenolic acids.Materials and methods. The object of the study was propolis collected in Lithuania, Poland, and Latvia in late July of 2006 and 2007. The qualitative and quantitative analysis of phenolic acids was performed using the high-performance liquid chromatography technique (HPLC).Results. The results of the study showed that the quantitative and qualitative composition of phenolic acids in propolis depended on the plants from which the bees in the area collected substances for the raw material of propolis. The predominant phenolic acids were determined to be ferulic and coumaric acids, and they may be among the main indicators of quality in the standardization of the raw material and preparations of propolis.Conclusion. We created an HPLC-based analysis method for the identification and quantification of phenolic acids in propolis. The variety of phenolic acids in propolis depends on the vegetation predominating in the harvesting area. Studies have shown that the highest amount of phenolic acids is observed in propolis harvested in areas characterized by the predominance of deciduous trees and meadows. Results have also shown that ferulic and coumaric acids are the predominant phenolic acids in propolis. The thickness of the layer of the collected propolis in the hive also influences its chemical composition.

Designing propolis products for external use involves determining the optimal form of propolis for the introduction into dermatological pharmaceuticals and cosmetic preparations. As a potent ingredient, propolis oil extract from raw material harvested in Lithuania was analysed. The rheological characteristics, content of phenolic compounds, major compounds and antimicrobial activity of the propolis oil extract are investigated here for the first time. The propolis oil extract was produced by maceration using different solvents, raw material was collected in Lithuania. Solvent mixture with 96% ethanol increased the rheological stability and extracted amount of phenolic compound. High-performance liquid chromatography identified the potent quality markers for Lithuanian propolis, phenylpropanoid vanillin, coumaric acid and ferulic acid. Antimicrobial activity of propolis oil extract was evaluated in experimental studies in vitro, and the minimal concentration of phenolic compounds that inhibited respective microorganisms was determined. The results demonstrate that phenolic compounds have effective antimicrobial activity in propolis oil extract; thus, it can be compatible with the semisolid preparation.

Royal jelly is a bee product with a high commercial interest due to its exceptional biological properties and unique composition. In this study, we evaluated the quality of Lithuanian Royal jelly, including the water content, antioxidant activity, amount of polyphenolic compounds and pH. The results indicated that Lithuanian Royal jelly had the values of pH, water content as well as polyphenols that were comparable to the data already published. In the study, we also evaluated the impact of various solvents on the amount of 10-hydroxy-2-decenoic acid (10-HDA), the main fatty acid, naturally occurring only in Royal jelly and which is the quality marker, in solutions obtaining the amount using the HPLC method. According to solubility tests performed, 10-HDA from Royal jelly is best soluble in ethanol of various concentrations, yet in order to be used for exceptional Royal jelly antibacterial and many other biological properties it was important to increase the solubility in aqueous solutions. Addition of β-cyclodextrin has increased the amount of 10-HDA in solution up to the level of ethanol solutions. The antioxidant and antibacterial tests have demonstrated that Lithuanian Royal jelly exhibits positive effects against free radicals, as well as mostly occurring bacterial strains, such as Esherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus. As the conclusion of this study, we can assume that the quality assessment methods chosen for this study, are significant for standardizing the procedures for further studies.

The active ingredients in the liquid extract of elderflower are responsible for the antibacterial, antioxidant and anti-inflammatory effects of the plant. The main objective of the investigation was to design semisolid formulations with the elderflower extract and evaluate their quality using the biopharmaceutical research method in vitro. The quality of the elderflower (Sambucus nigra L.) extracts was evaluated spectrophotometrically by determining the total amount of polyphenols and flavonoids. The antiradical activity was determined spectrophotometrically by employing the DPPH free radical scavenging method. The agar diffusion method was used to determine antibacterial activity in vitro. The modified diffusion cells of Franz type were used to perform the biopharmaceutical experiment in vitro of semisolid pharmaceutical formulations. The results revealed that the highest amount of active compounds were found in the extracts when 70% (v/v) ethanol was used for the extraction of raw material. The obtained extracts had antiradical activity and antimicrobial effects against S. aureus and B. cereus. An inverse correlation was found between the total amount of flavonoids released after 6 hours in vitro experiment and the dynamic viscosity of the formulations. The base and the amount of excipients affected the release of active compounds from the formulations during the experiment. The results of the study showed that, as the lipophilicity and viscosity of the base increased, the performance in formulations slowed down. The released amount of active compounds decreased when oleogel concentration in the formulation increased. The hydrophilic base was confirmed as the best carrier of the liquid extract of elderflower.