Claims for Patent: 6,377,847

Summary for Patent: 6,377,847

Title:	Iontophoretic drug delivery device and reservoir and method of making same
Abstract:	A reservoir electrode assembly of the present invention for an iontophoretic drug delivery device includes an electrode and a hydrophilic reservoir situated in electrically conductive relation to the electrode. The hydrophilic reservoir is formed from a bibulous hydrophilic cross-linked polymeric material having a first surface and a second surface that is adhesively adherent to the electrode. The first surface of the polymeric material is releasably adhesively adherent when applied to an area of a patient's skin. The polymeric material has a cohesive strength forms an adhesive bond with a bond strength between the second surface of the polymeric material to the electrode that is greater than the cohesive strength of the polymeric material. Additionally, an adhesive bond strength of the first surface of the polymeric material to the applied area of the patient is less than the cohesive strength of the polymeric material so that upon removal of the reservoir assembly of the invention from the applied area of the patient, substantially no polymeric material remains on the applied area and the hydrophilic reservoir remains substantially intact and adhesively adherent to the electrode.
Inventor(s):	Keusch; Preston (Hazlet, NJ), Vilambi; NRK (Jamaica Estates, NY), Eliash; Bruce Michael (Franklin Lakes, NJ)
Assignee:	Vyteris, Inc. (Fair Lawn, NJ)
Application Number:	09/328,329
Patent Claims:	1. An iontophoretic drug delivery device for delivering at least one medicament to an applied area of a patient, such as the skin, mucous membrane and the like, comprising: electrode assembly means, including an electrode, for driving a medication into the applied area of the patient to be absorbed by the body of the patient; and a covalently cross linked hydrophilic reservoir having a first surface and a second surface; wherein said second surface is situated in electrically conductive relation to the electrode assembly means, with said reservoir including an aqueous swollen cross linked water soluble polymer material having a degree of crosslinking varying from said first surface to said second surface, wherein said crosslinking results in tacky first and second surfaces that differ from one another in adhesive strength. 2. A reservoir electrode assembly for an iontophoretic drug delivery device comprising: an electrode; and a hydrophilic reservoir situated in electrically conductive relation to said electrode, said reservoir being formed from a bibulous hydrophilic cross-linked polymeric material having a first surface and a second surface being adhesively adherent to said electrode, said polymeric material having a degree of crosslinking varying from said first surface to said second surface, wherein said crosslinking results in tacky first and second surfaces that differ from one another in adhesive strength. 3. The reservoir electrode assembly of claim 2 wherein said hydrophilic reservoir further comprises a reinforcement to provide two-dimensional stability to said polymeric material and allow a swelling of said polymeric material in a third dimension. 4. The reservoir electrode assembly of claim 3 wherein said reinforcement is selected from the group consisting of a woven material and a non-woven material. 5. The reservoir electrode assembly of claim 4 wherein said reinforcement is formed from a non-woven material with a basis weight about ten to about thirty grams per square meter disposed substantially intermediate said first surface and said second surface of said bibulous hydrophilic polymeric material so that when said polymeric material imbibes an aqueous solution, said swelling of said polymeric material is substantially limited to increasing a distance between said first surface and said second surface and wherein said first surface and said second surface are substantially parallel to each other. 6. The reservoir electrode assembly of claim 5 wherein said bibulous hydrophilic polymeric material is poly(vinylpyrollidone) additionally being cross-linked to a preselected sufficient degree to be substantially shape retaining. 7. The reservoir electrode assembly of claim 6 wherein said poly(vinylpyrollidone) has a number average molecular weight above about 360,000 prior to said cross-linking. 8. The reservoir electrode assembly of claim 6 wherein said poly(vinylpyrollidone) is cross-linked by the application of a preselected quantity of ionizing radiation. 9. The reservoir electrode assembly of claim 8 wherein said poly(vinylpyrollidone) is swollen by a substantially uniform application to said first surface of an aqueous solution of at least one material selected from the group consisting of a medicament to be delivered to the patient, another medicament to be delivered to the patient, an electrolyte, another electrolyte, a preservative, a chelating agent, an antioxidant, a humectant and combinations thereof. 10. The electrode assembly of claim 2 wherein said cross-linked bibulous hydrophilic polymeric material has a swell ratio of greater than three when said bibulous hydrophilic polymeric material is charged with sufficient aqueous material to provide the preselected medicament delivery. 11. The reservoir electrode assembly of claim 2 wherein said electrode is formed from an application of a coating of an electrically conductive ink to a surface of a flexible substrate on said surface disposed against said second surface of said polymeric material. 12. The reservoir electrode assembly of claim 11 wherein said coating of said electrically conductive ink covers more than one half of said surface of said substrate disposed against said polymeric material. 13. The reservoir electrode assembly of claim 12 wherein said coating of said electrically conductive ink covers about ninety percent of said surface of said substrate disposed against said polymeric material, said ink coating being capable of being adhesively bonded to said second surface of said polymeric material. 14. The reservoir electrode assembly of claim 13 wherein said electrically conductive ink comprises silver and silver chloride. 15. The reservoir electrode assembly of claim 13 wherein said electrically conductive ink has a coat weight between about 1.5 and 5 grams per square cm. 16. The reservoir electrode assembly of claim 15 wherein said electrically coated ink has a resistivity of less than about 120 ohms per square. 17. The electrode assembly of claim 2 wherein a Tack Rolling Ball Measurement (TRBM) of the adhesive tack of the bibulous hydrophilic polymeric material is between about 5 mm to about 40 mm after cross-linking and prior to charging said reservoir with an aqueous medicament solution. 18. The electrode assembly of claim 17 wherein said TRBM of one side of said bibulous hydrophilic polymeric material is greater than about 15 mm and another side of said hydrophilic polymeric material is less than about 30 mm and wherein the TRBM of said sides are not the same. 19. A reservoir electrode assembly for an iontophoretic drug delivery device comprising: an electrode formed from an application of a coating of an electrically conductive ink to a surface of a flexible substrate; and a hydrophilic reservoir situated in electrically conductive relation to said electrode, said reservoir being formed from a bibulous hydrophilic cross-linked polymeric material having a first surface and a second surface being adhesively adherent to said electrode, said polymeric material having a degree of crosslinking varying from said first surface to said second surface and having a reinforcement therewithin to provide two-dimensional stability to said polymeric material and allow a swelling of said polymeric material in a third dimension, wherein said polymeric material has a degree of crosslinking varying from said first surface to said second surface, wherein said crosslinking results in tacky first and second surfaces that differ from one another in adhesive strength. 20. The reservoir electrode assembly of claim 19 wherein said reinforcement is formed from a non-woven material with a basis weight about ten to about thirty grams per square meter disposed substantially intermediate said first surface and said second surface of said bibulous hydrophilic polymeric material so that when said polymeric material imbibes an aqueous solution, said swelling of said polymeric material is substantially limited to increasing a distance between said first surface and said second surface and wherein said first surface and said second surface are substantially parallel to each other.