Potential role of resveratrol-loaded elastic sorbitan monostearate nanovesicles for the prevention of UV-induced skin damage.

This study was aiming to improve the effect of the water-insoluble drug, resveratrol, by encapsulating it in surfactant-based elastic vesicles (spanlastics). Spanlastics (SLs) were prepared by thin film hydration method using different ratios of Span 60 (S60) and edge activators (EAs). The prepared SLs were subjected to full in-vitro evaluation. All the SLs showed improved properties compared to the drug suspension ( p  < 0.05). SL5 composed of S60: Brij 35 (7:3) attained the highest drug entrapment efficiency (79.10%±5.56), the smallest particle size (201.30 nm ± 2.45), the best in-vitro anti-oxidant effect and a fast drug release pattern, thus was selected for further investigation. Based on the Draize test, the selected spanlastics (SL5), as well as the drug suspension, showed to be safe to be applied on the skin (PII <2). In-vivo studies were done to test the photoprotective effect of the designed nanovesicles compared to the drug suspension. Evaluation was done based on visual examination and analysis of some anti-oxidant markers (CAT, GSH and SOD), anti-inflammatory markers (IL-6, IL-8 and NF-κB) and anti-wrinkling markers (MMP-1 and GM-CSF) after UVB-irradiation. The drug showed a good prophylactic effect, however, that of SL5 was superior compared to that of the drug suspension as recorded by the level of all biochemical markers ( p  < 0.05). These results were also confirmed by histopathological examination. This study proves that elastic nanovesicles seem to be a promising approach to overcome the low drug solubility and to improve its efficacy.