Propolis organogel as a novel topical delivery system for treating wounds

Context: Propolis has traditionally been used in curing infections and healing wounds and burns. Objective: The aim of this study is to formulate pluronic lecithin organogel of propolis to improve its availability and antimicrobial activity. Materials and methods: Different organogels were prepared by using soybean lecithin, isopropyl palmitate, pluronic F127 and water. The effect of quantity of lecithin and pluronic F127 and percentage of oil phase was investigated. The organogels were evaluated for appearance, texture, pH, drug content and viscosity. In vitro release studies were carried out using cellophane membrane. Drug permeation through abdominal rat skin from organogels that showed high % drug release was compared to that from propolis suspension in distilled water. Finally, the antimicrobial activity of the selected propolis formulation against different bacterial isolates was compared with that of propolis suspension in water. Results and discussion: Results showed that all organogel formulations except the formula containing 10% pluronic F127, showed acceptable physical properties. Drug content of organogel formulations was in the range of 97.5- 100.2%. The pH of the formulations was in the range of 5.5- 6.3 that suits the skin pH, indicating skin compatibility. The viscosity was in the range of 5366- 8984 cp. A significant decrease in drug release from formulations was observed with increase in concentration of lecithin and pluronic F127. Decreasing oil phase percentage to 20% w/w led to a decrease in drug release from the formulation. Conclusion: The formula containing 3% lecithin and 20% pluronic F127 exhibited superior skin permeation and antimicrobial activity over propolis suspension in water.