摘要 |
Microspheres, of controllable shape and size, encapsulating active ingredients, are made by the internally controlled gelation of an emulsion including a water-soluble polysaccharide, a salt of a di- or trivalent metal cation, a polymerization inhibitor, water, a water-immiscible solvent (as a non-aqueous phase), and the active ingredient. The components of the aqueous phase, containing the water-soluble polysaccharide, polymerization inhibitor, di- or trivalent metal salt, active substance, and water, are blended together. This aqueous phase is then gradually mixed with the oil phase and agitated to form an emulsion. After sufficient time for solidification, the emulsion is broken and the resulting microspheres are collected. The active ingredient may be various substances, including live microorganisms.
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