2. Department of Pharmaceutical Sciences, School of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Brazil.
3. Medicinal Chemistry Laboratory and Regenerative Medicine (QUIMMERA)-University Center of Araraquara, Brazil.
Background: Besides the known propolis biological activities, widely reported in many scientific studies, new findings in animal models have opened new fields for propolis application. Recently, there has been an increased interest in dried extracts based on natural products including propolis, as the product in the dry presentation shows several advantages. Therefore, standardizing a more soluble dry extract and allowing the production of human dosage forms are of great interest. In this context, this work aimed to develop a propolis dry extract with high propolis and artepillin C contents.
Methods: The experiments followed a Box-Behnken design to study the effects of the process on the physicochemical properties of the powder using a spray drying equipment. The following drying excipients were used: silicon dioxide with arabic gum (encapsulating system A) and modified starch (encapsulating system B). Furthermore, physicochemical characterization, particle morphology by scanning electron microscopy and antibacterial assay of the samples were carried out.
Results: The results revealed that all variables of the process did not influence significantly propolis and flavonoid content, moisture and angle of repose in the encapsulating system A (arabic gum and silicon dioxide). For the encapsulating system B (modified starch and silicon dioxide), it was observed that the propolis content, flavonoid content, density, moisture and angle of repose were influenced significantly by the variables of the drying process parameters. Finally, p-coumaric acid, cinnamic acid and artepillin C were affected by the process conditions of system A, while, these biomarkers were not affected by the encapsulating system B. Both propolis dry extracts obtained were active against Staphylococcus aureus.
Conclusions: This study evidenced different encapsulating systems lead to different effects, depending on the drying process parameters. Both encapsulating systems allowed to obtain a standardized propolis extract with high flavonoid content and the expected amounts of artepillin C. Also, they maintained the antibacterial activity of propolis.
Keywords: Propolis dry extract, factorial design, artepillin C, standardized propolis extract, antibacterial activity