Abstract
Resveratrol is a naturally occurring polyphenol with strong antioxidant and free radical
scavenging properties, recently proposed as a therapeutic agent for skin diseases.
In this study, we investigated the possibility of improving the dermal bioavailability
of the poorly water-soluble drug resveratrol by nanocrystal technology. To this purpose,
nanosuspensions were prepared by the wet media milling technique, using Poloxamer
188 or Tween 80 as stabilizers, and characterized by means of both solid state and
morphological and dimensional studies. All analytical data demonstrated that neither
a modification of the drug crystalline pattern nor the isomerization of the trans double bond were observed after the wet media milling particle size reduction process,
which produced rounded and smooth nanocrystals with a mean diameter ranging between
0.2–0.3 µm. Resveratrol skin delivery from nanosuspension formulations was evaluated
by the pig ear skin model via tape stripping. Results of the experiments showed that
after application of nanosuspension formulations, higher amounts of resveratrol could
penetrate the skin at deeper levels compared to drug coarse suspensions. The antioxidant
activity of resveratrol in nanocrystals was assessed by the DPPH assay, which demonstrated
that the size reduction process as well as the formulation compositions did not modify
the drug antioxidant activity.
Key words
resveratrol - antioxidant - nanocrystals - nanosuspension - skin - tape stripping
