Claims for Patent: 5,186,938

Summary for Patent: 5,186,938

Title:	Adhesive transdermal dosage layer
Abstract:	An adhesive bilayer transdermal dosage system capable of sustained release of a pharmaceutically active drug to the skin of a human patient having a first component layer which is a pharmaceutically active drug-containing essentially planar sheet of an at least partially cross-linked acrylic adhesive. The planar sheet is formed of a flexible self-supporting cross-linked acrylate of sufficient adhesivity, durability and strength whereby intimate diffusional contact with the skin of the patient is maintained for a period of at least about 24 hours without destruction of the physical integrity of the sheet. The sheet is capable of retaining, dispersed therein, sufficient pharmaceutically active drug to deliver to the skin a pharmaceutically effective amount of the drug over a 24-hour period without dissolution of the at least partially crosss-linked acrylic adhesive. The system also contains a second component layer intimately adhered to one side of the first component layer. The second component layer is resistant to the passage of the pharmaceutically active drug from the first component layer. Methods for making the first component layer and dosage system are also disclosed.
Inventor(s):	Sablotsky; Steven (Miami, FL), Questel; John M. (Cuyahoga Falls, OH), Thompson; James A. (Akron, OH)
Assignee:	Key Pharmaceuticals, Inc. (Kenilworth, NJ)
Application Number:	07/744,632
Patent Claims:	1. An adhesive bilayer transdermal dosage system for the sustained release of nitroglycerin to the skin of a human patient, comprising: (i) a first component layer formed of a nitroglycerin-containing essentially planar sheet of an at least partially cross-linked acrylic pressure-sensitive adhesive, said essentially planar sheet comprising a flexible self-supporting cross-linked acrylate polymer of sufficient adhesivity, durability and strength whereby intimate diffusional contact with skin of the patient is maintained for a period of at least about 24 hours without destruction of the physical integrity of said sheet, said essentially planar sheet being capable of retaining dispersed therein sufficient nitroglycerin to deliver to the skin a pharmaceutically effective amount of said nitroglycerin over a 24-hour time interval, without dissolution of the at least partially cross-linked acrylic pressure-sensitive adhesive and (ii) a second component layer intimately adhered to one side of said first component layer, said second component layer being resistant to the passage of pharmaceutically active drug from said first component layer; wherein said first component layer comprises about 40 to about 80% by weight of acrylic adhesive; wherein said acrylic adhesive comprises about 1 to about 5% by weight of acrylic acid and about 5 to about 20% by weight of a C.sub.4 to C.sub.12 alkyl acrylate; about 20 to about 60% by weight of nitroglycerin; about 0.2 to about 1% of a cross-linking agent and 10% or less of water. 2. The adhesive bilayer transdermal dosage system of claim 1, further comprising: a release line placed over said first component layer on a surface opposite said second component layer, the release liner being resistant to the passage of pharmaceutically active drug from said first component layer. 3. The adhesive bilayer transdermal dosage unit of claim 1, wherein said pharmaceutically active drug is nitroglycerin which is delivered to the skin in an amount of from about 0.3 to 0.7 mg per square centimeter of said first component layer per 24-hour time interval. 4. The adhesive bilayer transdermal dosage system of claim 1, wherein said first component layer contains about 40 to about 80% by weight of acrylic adhesive; about 20 to about 60% by weight of pharmaceutically active drug; about 0.2 to about 1% of a cross-linking agent and 10% or less of water. 5. The adhesive bilayer transdermal dosage system of claim 1, wherein said acrylic adhesive is present in an amount of about 54 to about 70% by weight. 6. The adhesive bilayer transdermal dosage system of claim 4, wherein said pharmaceutically active drug is a vasodilator. 7. The adhesive bilayer transdermal dosage system of claim 1 wherein said nitroglycerin and is present in an amount in the range of about 30 to about 38.4% by weight. 8. The adhesive bilayer transdermal dosage system of claim 1, wherein said cross-linking agent is a melamine derivative present in the amount in the range of about 0.3 to about 0.8% by weight. 9. The adhesive bilayer transdermal dosage system of claim 1 wherein said first component layer contains a thickener in an amount of about 0.9 to about 1.8% by weight. 10. The adhesive bilayer transdermal dosage system of claim 1, wherein said water is present in an amount of about 4% by weight, said acrylic adhesive is present in an amount of about 61.4% by weight, nitroglycerin is present in an amount of about 33.4% by weight, said cross-linking agent is present in an amount of 0.4% by weight, and said thickener is present in an amount of about 1.0% by weight. 11. The adhesive bilayer transdermal dosage system of claim 1, wherein said acrylate polymer contains about 1 to about 5% by weight of acrylic acid and about 5 to 20% by weight of a C.sub.4 to C.sub.12 alkyl acrylate. 12. An adhesive transdermal layer for the sustained release of a pharmaceutically active drug to the skin of a human patient, comprising: a pharmaceutically active drug-containing essentially planar sheet of an at least partially cross-linked acrylic adhesive, said essentially planar sheet comprising a flexible self-supporting cross-linked acrylate polymer of sufficient adhesivity, durability and strength whereby intimate diffusional contact with skin of the patient is maintained for a period of at least about 24 hours without destruction of the physical integrity thereof, said essentially planar sheet being capable of retaining dispersed therein sufficient pharmaceutically active drug to deliver to the skin a pharmaceutically effective amount of said pharmaceutically active drug over a 24-hour time interval, without dissolution of the at least partially cross-linked acrylic pressure-sensitive adhesive. 13. The adhesive transdermal layer of claim 12, wherein said pharmaceutically active drug is a vasodilator. 14. The adhesive transdermal layer of claim 13, wherein said vasodilator is nitroglycerin. 15. The adhesive transdermal layer of claim 13, wherein said vasodilator is isosorbide dinitrate. 16. An adhesive transdermal layer for the sustained release of a pharmaceutically active drug formed by a) mixing an acrylic adhesive and water to form a homogeneous mixture; b) adding a pharmaceutically active drug to said homogeneous mixture; c) forming a smooth homogeneous mix of said pharmaceutically active drug and said homogeneous mixture; d) adding a cross-linking agent for said acrylic adhesive to said smooth homogeneous mix; e) undertaking cross-linking between said cross-linking agent and said acrylic adhesive; and f) removing sufficient water and solvent from the product of step e) to form said adhesive transdermal layer. 17. The adhesive transdermal layer of claim 1, wherein said pharmaceutically active drug is a vasodilator. 18. The adhesive transdermal layer of claim 17, wherein said vasodilator is nitroglycerin. 19. The adhesive transdermal layer of claim 18, wherein said nitroglycerin is present in an amount of 20 to 50% by weight based on said adhesive transdermal layer.