Preparation and Characterization of Ethyl Cellulose based Salbutamol Sulphate and Theophylline Combination Microsphere

The study is concerned with the development of Ethyl Cellulose microspheres by the o/w emulsification and solvent evaporation method in the presence of tween 80 as an emulsifying agent. The influence of process parameters such as solvent mixture, composition, concentration of the emulsifying agent and speed of stirring has been examined. The microspheres have been analysed for their size, drug loading capacity and drug release study. Spherical and smooth surfaced microspheres with desired encapsulation efficiencies were obtained. Slow drug release from microspheres observed up to6- 8 h. An optimization procedure was employed to investigate and identify the key parameters affecting the properties of the microspheres.