Microencapsulation of terbutaline sulphate by the solvent evaporation technique

Terbutaline sulphate microcapsules were prepared by coacervation-phase separation (solvent evaporation) technique using ethyl cellulose as a coating material. Acetone, ethyl alcohol and isopropyl alcohol were employed as solvents for coating material. Microcapsules were evaluated for their drug content, particle size distribution (microscopic method), flow properties, bulk density, in vitro dissolution, drug release kinetics and surface characteristics (scanning electron microscopy).