Thermosensitive In Situ Gelling System for Dermal Drug Delivery of Rutin

INTRODUCTION: Rutin has been broadly applied in the treatment of several diseases due to its pharmacological activities. However, its low aqueous solubility limits its absorption and bioavailability. The aim of this research is to increase the solubility of rutin using cyclodextrin and to develop a temperature-triggered in situ gelling system for dermal application.
METHODS: The solubility of Rutin was increased with SBE-β-CD. Rutin- SBE-β-CD inclusion complex was prepared by kneading and freeze dying method. Structural characterization was carried out using DSC and FTIR. İn situ gel formulations were prepared with Pluronic F127 (PF127), a thermosensitive polymer, and Chitosan (CH),a natural, biodegradable and mucoadhesive hydrophilic polymer. In situ gel characteristics like pH, clarity, gelation temperature and viscosity were determined.
RESULTS: When the solubility diagrams were examined, it was concluded that SBE-β CD showed a linear increase, therefore AL-type diagram was selected. The formulations were produced using different amounts of PF127 and a fixed ratio of CH. Three in situ gels were evaluated for their pH, gelling temperature and the rheological behaviors and one formulation was selected. It was observed that the formulations had a pH between 6-6,1, and their gelation temperature decreased with increasing PF127 which were between 20 °C to 34 °C. For the selected formulation(Formulation E3 ) 0.5% Rutin and Rutin/ SBE-β-CD were transfered to in situ gelling system. As a result of in vitro release studies, it was observed that the release of the Rutin/SBE-β-CD inclusion complex containing NZ formulation showed a higher burst effect than the others and the release continued for 6 hours.
DISCUSSION AND CONCLUSION: The results indicated that the combination of PF127 and CH can be a hopeful in situ gelling vehicle for dermal delivery of Rutin and Rutin/ SBE-β-CD.