Preparation and characterisation of ethylcellulose microparticles containing propolis

Abstract

Ethylcellulose microparticles containing propolis ethanolic extract (PE) were prepared by the emulsification and solvent evaporation method. Three ratios of ethylcellulose to PE dry residue value (DR) were tested (1:0.25, 1:4 and 1:10). Moreover, polysorbate 80 was used as emulsifier in the external phase (1.0 or 1.5% w/w). Regular particle morphology without amorphous and/or sticking characteristics was achieved only when an ethylcellulose:DR ratio of 1:0.25 and 1.0% polysorbate 80 were used. Microparticles had a mean diameter of 85.83 µm. The entrapment efficiency for propolis of the microparticles was 62.99 ± 0.52%. These ethylcellulose microparticles containing propolis would be useful for developing propolis aqueous dosage forms without the strong and unpleasant taste, aromatic odour and high ethanol concentration of PE.