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

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.

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.

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.

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.

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.