Preparation of enteric-coated microspheres of Mycoplasma hyopneumoniae vaccine with cellulose acetate phthalate: I. Formation condition and micromeritic properties

Abstract

The solvent evaporation method was employed to encapsulate Mycoplasma hyopneumoniae vaccine (MHV) using cellulose acetate phthalate (CAP) as an enteric coating material. Glucose was used as a diluent. The effect of some factors, such as encapsulating temperature, surfactant concentration, mechanical agitation and CAP concentration on the formation condition, particle size distribution, morphology, surface topography and antigen content of MHV microspheres, was investigated. The result indicates that the optimal operating conditions were: encapsulating temperatures, 20°C; stirring speed, 400 rpm; span 80 concentration, 0.6; and 8 per cent of CAP concentration, 30 ml. The optimal condition can be used to prepare the desirable microspheres. The content uniformity of MHV microspheres was also indicated.