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.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as:  
     
         1 . A drug delivery composition capable of gelling in situ containing approximately 0.01% to about 60% by weight of medicament or pharmaceutical, approximately 1-50% of water soluble film forming polymer and an ionic polysaccharide capable of cross-linking.  
     
     
         2 . The drug delivery composition of  claim 2  wherein the drug delivery composition is an aqueous composition.  
     
     
         3 . The drug delivery composition of  claim 2  wherein the drug delivery composition is a gel selected from the group consisting of hyperosmotic gel, hypoosmotic gel and an isoosmotic gel.  
     
     
         4 . The drug delivery composition of  claim 2  wherein the film forming polymer is water soluble.  
     
     
         5 . The drug delivery composition of  claim 2  wherein the film forming polymer is selected from the group consisting of methyl cellulose, ethyl cellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose, hyalauronic acid and salts thereof, sodium hyaluronate, chondroitin sulfate, polyacrylic acid, polyacrylamide, polycyanolacrylades, alkyl methacrylatepolymers, hydroxyalkyl methacrylate polymers, cyclodextrin, polydextrose, dextran, gelatin, polygalacturonic acid, poly vinyl alcohol, polyvinyl pyrollidone, polyalkylene glycols and polyethylene alcohol.  
     
     
         6 . The drug delivery composition of  claim 2  wherein the film forming polymer is selected from the group consisting of cyclodextrin, polydextrose, carrageenan and maltodextrins.  
     
     
         7 . The drug delivery composition of  claim 2  wherein the ionic poysaccharide is selected from the group consisting of natural gums such as gellan gum, alginate gums, ammonium and alkali metal salts of alginic acid, chitin and chitosan.  
     
     
         8 . The drug delivery composition of  claim 8  wherein the alginate gums are alkali metal alginates and the metal is selected from the group consisting of sodium, potassium, lithium, rubidium and cesium salts.  
     
     
         9 . The drug delivery composition of  claim 2  wherein the medicament is selected from the group consisting of antibacterials, antihistamines, decongestants, antiinflammatories, antiparisitics, miotics, anticholinergies, antivirals, local anesthetics, antifungals, immunosuppressants, amoebicidals, trichomonocidals, analgesics, mydriatics, antiglaucoma drugs, carbonic anyhydrase inhibitors, opthalmic diagnostic agents, opthalimic agents used as adjuvents in surgery, chelating agents, antineoplastics, antihypertensives, muscle relaxants and diagnostics.  
     
     
         10 . The drug delivery composition of  claim 2  wherein the medicament is an antibacterial substance selected from the group consisting of beta-lactam antibiotics, tetracyclines, chloramphenicol, neomycin, carbenicillin, colistin, penicillin G, polymyxin B, vancomycin, cefazolin, cephaloridine, chibrorifamycin, gramicidin, bacitracin and sulfonamides, gentamycin, kanamycin, amikacin, sisomicin, tobramycin.  
     
     
         11 . A drug delivery composition capable of gelling in situ upon release of a counter ion containing approximately 0.01% to about 60% by weight of medicament or pharmaceutical, approximately 1-50% of water soluble film forming polymer and an ionic polysaccharide capable of cross-linking.  
     
     
         12 . The drug delivery composition of  claim 12  wherein the counter ion is provided in latent form by microencapsulation of the counter ion in a heat sensitive medium which releases the counter ion at body temperature and causes the drug delivery composition to gel.  
     
     
         13 . The drug delivery composition of  claim 12  wherein the drug delivery composition further contains ion exchange resins which release the counter ion to gel the drug delivery composition in situ.  
     
     
         14 . The drug delivery composition of  claim 12  wherein the drug delivery composition contains anticancer agents.  
     
     
         15 . The drug delivery composition of  claim 12  wherein the ionic poysaccharide is selected from the group consisting of natural gums such as gellan gum, alginate polysaccharides, ammonium and alkali metal salts of alginic acid and chitin.  
     
     
         16 . The drug delivery composition of  claim 12  wherein the ionic polysaccharide is selected from the group consisting of gellan gum and alganite polysaccharides and the counter ions for gelling the ionic polysaccharide are selected from the group consisting of calcium, strontium, sodium, potassium, lithium, rubidium, cesium salts, strontium chloride and calcium chloride.  
     
     
         17 . A drug delivery composition which gels in situ which may be delivered topically to body cavities or by injection comprising approximately 0.01% to about 60% by weight of medicament or pharmaceutical, approximately 1-50% of water soluble film forming polymer, and an ionic polysaccharide which cross-links only after the drug delivery composition is administered in situ.  
     
     
         18 . The drug delivery composition of  claim 18  wherein the medicament of pharmaceutical is selected from the group consisting of antibacterials, antihistamines, decongestants, antiunflammatories, antiparisitics, miotics, anticholinergies, antivirals, local anesthetics, antifungals, immunosuppressants, amoebicidals, trichomonocidals, analgesics, mydriatics, antiglaucoma drugs, carbonic anyhydrase inhibitors, opthalmic diagnostic agents, opthalimic agents used as adjuvents in surgery, chelating agents, antineoplastics, antihypertensives, muscle relaxants and diagnostics.  
     
     
         19 . The drug delivery composition of  claim 18  wherein the ionic poysaccharide is selected from the group consisting of natural gums such as gellan gum, alginate polysaccharides, ammonium and alkali metal salts of alginic acid and chitin.  
     
     
         20 . The drug delivery composition of  claim 18  wherein the drug delivery composition of is water soluble.