Medical uses of in situ formed gels

Abstract

Balanced pH, hyperosmotic, hypoosmotic, or isoosmotic gels are ideal vehicles for drug delivery. They are especially suited for topical body cavity or injection application of drugs or diagnostic agents; for drug or diagnostic agent delivery to the eye of a mammal; as protective corneal shields; or as ablatable corneal masks useful in laser reprofiling of the cornea. The compositions without the addition of a drug or diagnostic agent are useful as medical devices, for instance, in separating surgically or otherwise injured tissue as a means of preventing adhesions.

Description

[0001] This application is a continuation of U.S. Ser. No. 09 / 628,227, filed Jul. 28, 2000, which is a continuation of U.S. Ser. No. 09 / 330,618, filed Jun. 11, 1999, now U.S. Pat. No. 6,136,334, which is a continuation of U.S. Ser. No.08 / 773,755, filed Dec. 23, 1996, now U.S. Pat. No. 5,958,443 which is a continuation of U.S. Ser. No. 08 / 174,101 filed Dec. 28, 1993, now U.S. Pat. No. 5,587,175, which is a divisional of U.S. Ser. No. 07 / 785,305, filed Oct. 30, 1991, now U.S. Pat. No. 5,318,780.[0002] This invention relates to drug delivery system, the prevention of post-surgical adhesions, ophthalmic corneal protective devices, and a surgical device used in the correction, for instance, of corneal ulcers, irregularities, scarring, astigmatism, myopia, and hyperopia.DESCRIPTION OF THE PRIOR ART[0003] Over the years, methods have been developed to achieve the efficient delivery of a therapeutic drug to a mammalian body part requiring pharmaceutical treatment. Use of an aqueous liquid w...

AI Technical Summary

Problems solved by technology

These are often not satisfactory because they lack sufficient flexibility to adequately conform to the individual corneal curvature.

Wetting a collagen shield will increase conformance of the shield to the cornea but fragmentation can occur upon exceeding the flexibility of the collagen shield.

Refractive surgery has been promoted in the United States and Russia over the past few years but its acceptance has been limited because of the poor predictability of the final optical results which include resulting glare from incisions that encroach upon the optical zone.

Techniques that rely upon the surgical production of corneal incisions have yielded inconsistent results because these surgical incisions in the cornea have been found to vary considerably in depth and length.

Since the primary locus of astigmatism is in the cornea, surgical intervention for astigmatism is more important than for the correction of other refractive errors, especially since spectacle or contact lens correction is of limited value in compensating for large astigmatic errors.

A complete listing of useful water soluble, film forming polymers is not possible.

In addition, it is noted that a large percentage of drugs administered to the eye are lost as a result of lacrimal drainage.

While progress has been made in the delivery of drugs by the use of solid implants, many patients find it difficult to tolerate the introduction of the implants into the conjunctival areas.