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Microencapsulation of water-soluble medicaments

  • US 5,503,851 A
  • Filed: 07/01/1993
  • Issued: 04/02/1996
  • Est. Priority Date: 07/10/1992
  • Status: Expired due to Term
First Claim
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1. A process for the microencapsulation of water-soluble active ingredients according to the principle of phase separation which comprises the steps of:

  • a) preparing a solution of a biocompatible polymer in an organic solvent;

    b) adding an aqueous solution of one or more active ingredients to or dispersing one or more solid active ingredients in the solution from stage (a);

    c) adding a coacervation agent to the emulsion or the dispersion from stage (b) forming microcapsules in the solution;

    d) introducing the mixture from stage (c) into an excess of a liquid, non-hydrogenated hardening agent; and

    e) separating the microcapsules from the hardening agent, collecting and washing the microcapsules to remove substantially all of the hardening agent,wherein liquid, non-hydrogenated natural or synthetic esters of saturated C4 to C18 carboxylic acids and polyhydric alcohols are used as hardening agent in an excess amount of up to 30 times the total volume of polymer solvent and coacervation agent.

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