Claims for Patent: 5,292,515

Summary for Patent: 5,292,515

Title:	Manufacture of water-swellable hydrophilic articles and drug delivery devices
Abstract:	A method of preparing a hydrophilic plastic cartridge by centrifugally cang polymerizable hydrophilic material in a rotating polymerization tube whose longitudinal axis is maintained parallel to the ground. The speed of rotation causes radial outward displacement of the polymerizable material which upon assuming a predetermined shape within the rotating tube is then polymerized to the predetermined solid configuration. The resulting plastic cartridge is characterized by smooth, unscored internal and external cylindrical surfaces. The cartridges are used as a rate-limiting membrane in drug delivery devices. Sterilized kits containing a disposable needle/syringe or trocar-like instrument and the drug delivery device are used for subcutaneous implantation of the device in an animal body.
Inventor(s):	Moro; Daniel G. (Randolph, NJ), Kuzma; Petr (Monmouth Junction, NJ), Quandt; Harry (North Middletown, NJ)
Assignee:	Hydro Med Sciences, a Division of National Patent Development Corporation (New York, NY)
Application Number:	08/041,523
Patent Claims:	1. A method for centrifugally casting a biocompatible, non-biodegradable, water-swellable, water-insoluble, hydrophilic plastic cartridge of uniform wall thickness useful as a rate-limiting barrier in a drug delivery device which comprises: a. rotating a tube comprising a core of smooth uniform cylindrical surface, said tube containing a predetermined quantity of at least one polymerizable hydrophilic liquid monomer and closure means to prevent loss of said liquid monomer during rotation; b. maintaining the longitudinal axis of the rotating tube parallel to the ground and effecting the rotation at a speed sufficient to cause radially outward displacement of said liquid monomer to assume a cylindrically-shaped liquid cartridge having a predetermined configuration within said tube; c. subjecting the tube to polymerization conditions to convert said liquid state cartridge to a solid state hollow plastic cartridge of predetermined configuration; and d. recovering a biocompatible, non-degradable, water-swellable, water-insoluble, hydrophilic cylindrically-shaped plastic cartridge having walls of uniform thickness between its smooth external and internal cylindrical surfaces. 2. The method of claim 1 wherein said polymerizable liquid monomer comprises hydrophilic ethylenically unsaturated monomers and an agent to effect the catalysis thereof. 3. The method of claim 2 wherein the polymerization reaction is carried out in the presence of radiation and a catalyst therefor. 4. The method of claim 3 wherein said polymerizable liquid monomer contains benzoin methyl ether as an initiator and wherein said radiation is ultra-violet light. 5. The method of claim 2 wherein the outer portion proximal to the closed end of said cartridge is subjected to a shaving step thereby imparting a smooth oval shape to the cartridge. 6. The method of claim 5 wherein said cartridge is a xerogel. 7. The method of claim 6 wherein said cartridge is a hydrogel. 8. The method for the preparation of a delivery device for the sustained release of an active agent therefrom which comprises: a. introducing active agent, and optionally a pharmaceutically acceptable carrier, into a cylindrically-shaped reservoir of a biocompatible, non-biodegradable water-swellable, water-insoluble, cylindrically-shaped plastic cartridge, in an amount sufficient to provide extended sustained release of the active agent, said cartridge having smooth external and internal cylindrical surfaces and a uniform thickness between said surfaces; b. introducing at least one polymerizable liquid monomer into the upper portion of said reservoir in an amount to close the open end of the reservoir, said polymerizable liquid monomer having an equilibrium water content value in its polymerized state which exceeds the equilibrium water content value of said plastic cartridge; and c. polymerizing said polymerizable liquid monomer to effectively seal the opening of the reservoir with a plug of water-swellable, water-insoluble polymer to form a delivery device which give a predetermined release of the active agent. 9. The method of claim 8 wherein said plastic cartridge has a smooth, oval cylindrical shape. 10. The method of claim 8 wherein the outer portion of the delivery device distal to the plug of polymer is subjected to a shaping step to impart a smooth oval shape thereto. 11. The method of claim 8 wherein said active agent is a drug. 12. The method of claim 11 wherein said drug is a macromolecular composition having an average molecular weight upwards to about 25,000. 13. The method of claim 12 wherein said macromolecular composition includes native and recombinant bioactive proteins. 14. The method of claim 12 wherein said macromolecular composition is a hormonally active polypeptide. 15. The method of claim 12 wherein said macromolecular composition is luteinizing hormone-releasing hormone polypeptide. 16. The method of claim 12 wherein said macromolecular composition is a mammalian growth hormone or mammalian growth releasing hormone. 17. The method of claim 8 wherein said plastic cartridge is a xerogel. 18. The method of claim 8 wherein said plastic cartridge is a hydrogel. 19. The method of claim 8 wherein said plastic cartridge is a hydrogel at its equilibrium water content. 20. The method of claim 17 wherein said polymerizable liquid material comprises an homogenous mixture of ethylenically-unsaturated monomer and a water-soluble pore-forming agent. 21. As an article, a biocompatible, non-biodegradable, water-swellable, water-insoluble, hydrophilic plastic cartridge useful as a rate-limiting barrier in a drug delivery device capable of being implanted in an animal by perforation, said plastic cartridge characterized by an oval cylindrical shape at its closed end, smooth unscored internal and external cylindrical surfaces, and a uniform thickness between said surfaces. 22. The article of claim 21 wherein the plastic cartridge is in the state of a xerogel. 23. The article of claim 21 wherein the plastic cartridge is hydrated. 24. The article of claim 21 wherein the plastic cartridge is a polymer of 2-hydroxyethyl methacrylate. 25. The article of claim 24 wherein the internal cylindrical surface area proximal to the open end of the cartridge has been scored and treated with a mono- or polyhydric alcohol to enhance graft polymerization of polymerizable ethylenically unsaturated monomer thereto. 26. A delivery device for the sustained release of an active agent therefrom which comprises: a. biocompatible, non-biodegradable, water-swellable, water-insoluble, hydrophilic plastic cartridge having a cylindrically-shaped reservoir; b. said cartridge characterized by (i) an oval outer cylindrical shape at one end thereof; (ii) smooth internal and external cylindrical surfaces; and (iii) a uniform cylindrical wall thickness; c. sealant means for closure of the open end of said reservoir comprising a plug of biocompatible, non-biodegradable, water-swellable, water-insoluble, hydrophilic polymer having an equilibrium water content value greater than that of the plastic cartridge per se; and d. an active agent contained in the reservoir of the cartridge in an amount sufficient to provide a predetermined sustained release thereof over an extended period of time. 27. The delivery of claim 26 wherein said active agent is a drug. 28. The delivery device of claim 26 wherein said active agent is a macromolecular composition having a molecular weight of upwards to 25,000. 29. The delivery device of claim 26 wherein said plastic cartridge and said sealant means are in the xerogel state. 30. The delivery device of claim 26 wherein said plastic cartridge and said sealant means are in the hydrogel state. 31. The delivery device of claim 26 wherein said active agent includes native and recombinant bioactive proteins. 32. The delivery device of claim 31 wherein said active agent is a hormonally active polypeptide. 33. The delivery device of claim 32 wherein said active agent is luteinizing hormone-releasing hormone polypeptide. 34. The delivery device of claim 26 wherein said active agent is a mammalian growth hormone or mammalian growth releasing hormone. 35. The delivery device of claim 33 wherein said delivery device contains a pharmaceutically acceptable carrier admixed with the active agent. 36. A method for the implantation of a small cylindrically-shaped delivery device into an animal for sustained release of an active agent therefrom which comprises: a. perforating the skin of an animal at a preselected site with an instrument comprising a hollow needle and the delivery device of claim 26; b. injecting said delivery device through said hollow needle and depositing it subcutaneously at the preselected site; and c. withdrawing said needle from the animal. 37. The method of claim 36 wherein said active agent comprises native or recombinant bioactive proteins. 38. The method of claim 37 wherein said active agent is a luteinizing hormone-releasing hormone polypeptide. 39. The method of claim 38 wherein the delivery device comprises a cartridge in a zerogel state. 40. The method of claim 38 wherein the delivery device comprises a cartridge in a hydrated state. 41. A kit useful for the implantation by perforation of a drug delivery device in an animal for sustained release of a drug therefrom comprising: a. the drug delivery device of claim 37; b. delivery means to eject said drug delivery device to the delivery environment of an animal; and c. container means to house said delivery device and said delivery means in a sterile aqueous medium. 42. The kit of claim 41 wherein said delivery means comprises a small rigid hollow tube of uniform internal diameter having a needle-like opening at one end thereof, and a telescoping solid rigid rod slidably communicating with the internal surface of said tube, and wherein said drug delivery device positioned within said tube is proximity with one end of the rod for slidable ejection from said tube.