| 摘要 |
The object of the present invention is a process for preparing microparticles of the microsphere type of a water-soluble substance and a biocompatible and biodegradable polymer controlling the release kinetics of said substance, consisting of a matrix of said polymer within which said water-soluble substance is regularly dispersed, in which: (a) said polymer is dissolved in a first volatile organic solvent not miscible with water; (b) said water-soluble substance is dissolved in a second solvent miscible with the first, is a solvent of a polymer and miscible with water; (c) the solution of said substance and that of said polymer are mixed; (d) an organic phase of the polymer and said substance which is then emulsified in a non-miscible dispersant medium consisting of an aqueous phase containing an emulsifying agent; (e) the two solvents are then eliminated from the microspheres being formed, the first by evaporation and the second and a part of the first miscible therewith by transition to the aqueous phase by a phase separation mechanism; (f) after the sovlents have been eliminated, the microspheres formed are recovered, possibly after washing in water and sieving.
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