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Processes for preparation of microspheres

  • US 4,166,800 A
  • Filed: 07/31/1978
  • Issued: 09/04/1979
  • Est. Priority Date: 08/25/1977
  • Status: Expired due to Term
First Claim
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1. In a process for the preparation of microspheres having a particulate core material encapsulated by a polymeric coating wherein the polymer is dissolved in a solvent in which the core material is not soluble and the polymer is precipated by phase separation to encapsulate the core material by the addition of phase separation agent to the polymer-core material-solvent system;

  • the improvement which comprises lowering the temperature of said system from about -40°

    to -100°

    C. and then adding the phase separation agent to the polymer-core material-solvent system to cause phase separation of the polymer.

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