A simple, fast method of high-performance liquid chromatography for the determination and quantification of arbutin and hydroquinone in many different raw materials was developed and validated. The optimum conditions for the separation and detection of these two constituents were achieved on a LiChro-CARD 125-4 Superspher®100 RP-18 column with the water-methanol (gradient elution) mobile phase and recorded at 289 nm. The purities of peaks were verified by PDA analysis of impurities. The results of validation have shown that the HPLC method is stable and accurate for the simultaneous determination of arbutin and hydroquinone in extracts from various plants. The developed method gave a good sensitivity (LOD 1µg/ml for arbutin and 0.49 µg/ml for hydroquinone) with linearity R 2 >0.9993 (for both). The relative standard deviation of the method was less than 2.53% for intra-day assays and 3.23% for inter-day assay, the accuracy of the recovery test ranged from 98.96% to 106.4%. This method was used in comparative qualitative analysis of arbutin and hydroquinone in 16 different raw materials from families Lamiaceae, Ericacaeae, Saxifragaceae, Rosaceae. The content of arbutin in B. ciliata, B. cordifolia and Ledum palustre was examined for the first time.

Summary Introduction: Green tea offers not only pleasant, delicate flavor, but also provides health benefits. The extract contains, among others, polyphenols responsible for antioxidant and anti-inflammatory properties. They reduce the risk of cancer and their presence exerts preventive activity against cardiovascular diseases. Objective: Analysis of selected physicochemical and solubilizing properties of pharmacopoeial-true solutions of dry green tea extract. Methods: The caffeine content was determined in the extract and in dry residue after solubilization by high performance liquid chromatography. The process of micellar solubilization of cholesterol granules and ketoprofen was carried out in model solutions of green tea extract. Results: The obtained results indicate that the prepared ‘ex tempore’ leaf green tea infusion subjected to short thermal exposure will be characterized by significant solubilization abilities. Conclusions: The outcomes of the research pointed to the possibility of developing a solid oral dosage form with titrated dry green tea extract of expected pharmacotherapeutic profile.

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