Taxifolin: Evaluation Through Ex vivo Permeations on Human Skin and Porcine Vaginal Mucosa.

BACKGROUND: Taxifolin (TAX) is a flavonoid that has numerous pharmacological properties, including an antioxidant ability superior to that of other flavonoids due to its particular structure. Nevertheless, it has low oral bioavailability, which limits its therapeutic application. In this context, potentially important approaches for systemic drug delivery could be by alternative routes such as skin and vaginal mucosa, once both routes have a variety of advantages compared with the oral route, including the ability to bypass both first-pass hepatic metabolism and the consequent degradation in the gastrointestinal tract. Vaginal delivery could also account for a local effect, or an effect on circumvent microregion. OBJECTIVE: The major objective of this study was to develop and validate a high-performance liquid chromatography (HPLC) method for the determination of TAX in a semisolid dosage forms and then to evaluate ex vivo permeations across porcine vaginal mucosa and human skin. METHODS: TAX was incorporated into an oil-in-water emulsion developed previously by our group. Method for quantification was developed and validated using HPLC. Permeation through human skin and vaginal porcine mucosa were conducted in Franz-type cells. RESULTS: The method was precise (CV < 5%), accurate (recovery between 98% and 102%), linear (R2> 0.99), specific, and robust. Permeation experiments through porcine vaginal mucosa and human skin presented permeated percentages equal to 87.43% and 48.09% (per dose), respectively. CONCLUSION: The results suggest that, in the matrixes studied, TAX may be able to exert its biological activities systemically when applied by these routes. Furthermore, it exhibits greater permeability potential when administered by intravaginal route.

A rapid method for total Β-escin analysis in dry, hydroalcoholic and hydroglycolic extracts of Aesculus hippocastanum L. by capillary zone electrophoresis.

INTRODUCTION: Seeds of Aesculus hippocastanum L. are used in European phytotherapy to treat inflammatory and vascular problems, and also to help in the regulation of the microcirculation. Thus, the quality control of herbal medicines using this species is important. OBJECTIVE: To develop and to optimise a capillary zone electrophoresis method to determine total ß-escin in different extracts of A. hippocastanum L. METHODS: The optimal condition found through chemometric approach was: 25 mmol/L of bicarbonate-carbonate buffer, pH 10.3; +20 kV of voltage; 20°C of cartridge temperature; direct ultraviolet detection at 226 nm; 13 mbar injection for 5 s and analysis time within 6 min. RESULTS: Repeatability, coefficient of variation (CV; %) = 3.19, 3.07 and 1.89 (n = 12), and intermediate precision, CV (%) = 3.05, 3.53 and 2.99 (n = 24) for dry, hydroalcoholic and hydroglycolic extracts, respectively were achieved. The accuracy was evaluated through recovery tests in concentration levels of 100, 150 and 200 g/L, ranging from 98.17 to 104.68%. The proposed method exhibited linearity (r = 0.9983) in the concentration range from 101.4 to 907.2 g/L and limits of detection and quantification equal to 11.63 and 38.76 g/L respectively. CONCLUSION: A fast and reliable methodology for determination of total ß-escin was successfully validated and applied on extracts of A. hippocastanum L. demonstrating its usefulness to quality control of medicines containing this plant species.