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Liquid ophthalmic sustained release delivery system

  • US 5,422,116 A
  • Filed: 02/18/1994
  • Issued: 06/06/1995
  • Est. Priority Date: 02/18/1994
  • Status: Expired due to Term
First Claim
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1. A method of providing a slow and sustained release of an ophthalmic treating agent to the eye of a mammal which comprises administering to the eye of a said mammal an effective amount of a homogeneous liquid aqueous ophthalmic pharmaceutical composition, of pH between about 3.0 and about 6.2, which is administrable in drop form and which comprises an ophthalmically effective concentration of a said ophthalmic treating agent and about 0.05% to about 10% by weight of the polymer chitosan as the release rate controlling agent;

  • said polymer consisting essentially of(A) monomeric β

    (1→

    4)-D-glucosamine linked units and of(B) monomeric β

    (1→

    4)-N-acetyl-D-glucosamine linked units which are scattered randomly in themolecule of the polymer, the numerical proportions of A and B being from about 60 to about 99% of A and about 1 to about 40% of B, and the viscosity rating of the polymer being from about 3 to about 3000 cps;

    in which method, upon contact with the higher pH of the ocular fluid, said liquid formulation is converted to a stiff gel from which the ophthalmic treating agent is slowly released over a prolonged period of time.

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