|
PatentVote.com: Vote on your favourite invention!
|
|
 |
Title: Structured bioerodible drug delivery device
Claims: What is claimed is: 1. A delivery device for the sustained administration of a predetermined dosage of an ophthalmic drug to the eye of a mammalian patient comprising (1) an inner reservoir comprised of a biodegradable material that degrades to innocuous products in response to the biological ocular environment of the patient, said reservoir containing an ophthalmic drug formulation confined therein, and (2) an outer membrane surrounding the inner reservoir, the membrane permeable to the passage of ophthalmic drug, but at a lower rate than through the inner reservoir, the membrane formed from drug release rate controlling bioerodible material consisting of a polyvalent metal ion cross-linked anionic polyelectrolyte, said ion a member selected from the group consisting of aluminum, barium, cadmium, calcium, copper, iron, zinc and mixtures thereof, said polyelectrolyte a member selected from the group consisting of cellulose, hemicellulose, starch, polystyrene sulfonic acid, polyvinyl sulfonic acid, polyvinyl methylol sulfonic acid, polyacrylic acid, polymethacrylic acid, acrylic copolymers, methacrylic copolymers, polyvinyl alcohol, polyvinyl chloride, glycans and polysaccharides, which outer membrane bioerodes in the eye of the patient in response to the biological environment therein by a process of polyvalent metal ion displacement by noncross-linking ions present in the eye, and wherein when in the ocular environment the membrane continuously meters the flow of a therapeutically effective amount of ophthalmic drug from the reservoir to the eye of the patient at a controlled and continuous rate over a prolonged period of time. 2. The delivery device according to claim 1 wherein the inner reservoir is formed of poly(lactic acid) containing an ophthalmic drug, and the outer membrane is formed of zinc chloride cross-linked alginate. 3. A device for administering an ophthalmic drug to the eye according to claim 1 wherein the drug is a member selected from the group consisting of tetracycline, chlortetracycline, bacitracin, neomycin, polymyxin, gramicidin, oxytetracycline, chloramphenicol, gentamycin, and erthromycin. 4. A device for administering an ophthalmic drug to the eye according to claim 1 wherein the drug is a member selected from the group consisting of hydrocortisone, hydrocortisone acetate, dexamethasone, dexamethasone 21-phosphate, fluocinolone, medrysone, prednisolone, methylprednisolone, predisolone 21-phosphate, prednisolone acetate, fluoromethalone, betamethasone, and triamcinolone. 5. A device for administering an ophthalmic drug to the eye according to claim 1 wherein the drug is a member selected from the group consisting of idoxuridine, pilocarpine, phospholine iodide, demecarium bromide, cyclopentolate, hematropine, scopolamine, epinephrine and eserine salicylate. 6. A bioerodible delivery device for the sustained administration of a predetermined dosage of ophthalmic drug to the eye of a mammalian patient consisting of a matrix of polyvalent cation cross-linked anionic polyelectrolyte material that bioerodes in the biological ocular environment by displacement of the cation by a noncross-linking ion to form a non-toxic product, said material having distributed throughout a plurality of microporous reservoirs with each of the reservoirs consisting of an ophthalmic drug formulation confined within the rate controlling material, the reservoir characterized by being selected from a group consisting of (1) a microcapsule of an initial size and configuration capable of being eliminated from the ocular cavity through the punctum with tear fluid and formed of a material that degrades to innocuous products in response to the biological environment, and (2) a microcapsule of biodegradable material that degrades to innocuous products in the eye in response to the ocular environment; the matrix material being permeable to the passage of ophthalmic drug at a higher rate than through the drug release rate controlling material with the latter material metering a therapeutically effective amount of ophthalmic drug from the reservoir to the eye of the patient at a controlled and continuous rate over a prolonged period of time. 7. The delivery device according to claim 6 wherein the microcapsules are formed of poly(lactic acid) containing an ophthalmic drug and the matrix is formed of zinc chloride cross-linked alginate. 8. A device for administering an ophthalmic drug to the eye according to claim 6 wherein the drug is a member selected from the group consisting of antibiotic, antibacterial, antiviral, antiallergenic, anti-inflammatory, miotic, antichlolinesterase, decongestant and sympathomimetic drugs. 9. A device for administering an ophthalmic drug to the eye according to claim 6 wherein the drug is a member selected from the group consisting of idoxuridine, pilocarpine, phospholine iodide, demecarium bromide, cyclopentolate, hematropine, scopolamine, epinephrine, and eserine salicylate. Other info: Inventors: Michaels, Alan S. (Atherton, CA, US) Application Number: 517982 Filing Date: 1974-10-25 Publication_date: 1976-06-08 Assignee: Alza Corporation (Palo Alto, CA) Primary Class(es): 424/473 424/469, 424/480, 424/481 Other Classes: US Patent Ref:
Other Refs: Primary Examiner: Rose, Shep K. Assistant Examiner: Attorney: Sabatine; Paul L. |
|