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Controlled release system and method for manufacturing the same

  • US 8,512,748 B2
  • Filed: 08/13/2007
  • Issued: 08/20/2013
  • Est. Priority Date: 08/25/2006
  • Status: Active Grant
First Claim
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1. A pharmaceutical controlled release system for administration of active substances with pH-dependent solubilities, comprising:

  • a) a core material comprising one or more pharmaceutically acceptable pH modifiers, wherein at least one pharmaceutically acceptable pH modifier is an organic acid;

    b) a first insulating layer, provided on the core material, comprising one or more pharmaceutically acceptable water soluble polymers;

    c) a second layer comprising a pharmaceutically acceptable water-insoluble (poly(ethyl acrylate/methyl methacrylate/trimethylammonioethyl methacrylate chloride)polymer having either a 1;

    2;

    0.1 or 1;

    2;

    0.2 ratio of ethyl acrylate to methyl methacrylate to trimethylammonioethyl methacrylate chloride monomers;

    d) a third layer comprising at least one active substance having a pH-dependent solubility;

    e) a fourth layer comprising one or more pharmaceutically acceptable polymers having anionic or no ionic groups; and

    f) optionally a fifth layer.

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