Formulation and antimicrobial studies of microencapsulated Musanga cecropioides stem bark extract

Microencapsulation is the process of coating small droplets of liquid or solid materials with a continuous film of polymeric substances. The aim of the research was to formulate microparticles of Musanga cecropioides stem bark extract. The dried, powdered stem bark of Musanga cecropioides was extracted by maceration. The aqueous extract was microencapsulated using polymers such as alginate, pectin and hydroxylpropyl methylcellulose acetate succinate (HPMCAS) by counter-ion coacervation method using an electrostatic droplet generator. The formulated microcapsules were evaluated for flow properties, particle size, drug content, antimicrobial activity and in vitro release kinetics in simulated gastric and intestinal fluids. The microparticles were subjected to stability tests under different temperature (45°C, 25°C and 8°C) and relative humidity (100% RH, 78% RH and 0% RH) conditions for a period of three (3) months. The mean particle size of the microcapsules decreased with increasing applied voltage of the electrostatic generator. Particle size range for the batches of formulated microparticles was 68.20-223.84μm. The percentage entrapment efficiency of the batches of microparticles ranged from 80.26-86.58%. The microparticles lost a significant percent of its drug content after storage at different temperature and relative humidity conditions. The formulated microparticles and crude extract possess significant antibacterial action against both gram positive and negative bacteria as well as antifungal effect against C. albicans. Microparticles of M. cecropioides extract were formulated by counter-ion coacervation method using an electrostatic droplet generator which conferred advantages of sustained drug release, reduced frequency of dosing, masked unpalatable taste, improved stability and enhanced patient acceptance on the crude extract.