Chitosan based Pickering emulsion as a promising approach for topical application of rutin in a solubilized form intended for wound healing: In vitro and in vivo study

The aim of the present study is to formulate the hydrophobic drug rutin in a solubilized form, intended for wound healing, via its loading into a novel Pickering emulsion stabilized by self aggregated chitosan particles (SACP). Rutin-loaded Pickering emulsion formulae were prepared using a high speed homogenizer. They were characterized by drop test, optical microscopy, droplet size and zeta potential determination. The results revealed that SACP have a nano size and a contact angle of 42.47 +/- 1.19 degrees that tend to stabilize O/W emulsion. The droplet size of all investigated formulations ranged between 5.8 +/- 1.1 and 18.7 +/- 3.4 mu m. The long term stability study revealed that formulae containing 20% and 30% oily phase were stable against coalescence, the droplet size was slightly increased with zeta potential ranged from -48.1 +/- 4.7 to -78.4 +/- 4.1 mV, during the storage period up to 5 months, indicating good stability. The release of rutin was almost 100% within 24 h. Treatment of the wounded skin tissue of the Albino rats with the selected formula, for ten days, revealed almost complete healing. Biochemical analysis for oxidative stress markers, hyaluronic acid and collagen type I in addition to histopathological study were performed. The results suggested that the sustained release of rutin in a solubilized form as well as the synergistic effect of other components of the prepared Pickering emulsion could have a potential wound healing effect.