| 摘要 |
Disclosed is a sustained release liquid aqueous ophthalmic delivery system a nd a method of providing a slow and sustained release of ophthalmic treating agents 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; said polymer consisting essentially of (A) monomeric .beta.(14)-D-glucosamine linked units and of (B) monomeric .beta.(14)-N-acetyl-D-glucosamine linked units which are scattered randomly in the molecule 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, the viscosity rating 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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