EP0197504A2
Expired / Lapsed
EP
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pH-mediated drug delivery system
Assignee: Merck and Co Inc
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Filing: 1986-04-03
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Granted: —
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Expires: 2006-04-03
Abstract
Abstract A transdermal delivery system suitable for administering a weakly acidic or basic drug is described which comprises a substantially impermeable backing member, a drug reservoir comprising the drug, a hydroxylated solvent and a buffering agent, and a membrane selectively permeable to the unionized form of the drug and substantially impermeable to the ionized form of the drug and the buffer salts.
Inventors
- 👤 Joseph V. Bondi
- 👤 Alice E. Loper
- 👤 Edward M. Cohen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 19:04
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/70; A61K9/7023; A61K9/703; A61K9/7084
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
62 words
A transdermal delivery system suitable for administering a weakly acidic or basic drug which comprises a) a substantially impermeable backing member, b) a drug reservoir comprising the drug, a hydroxylated solvent and a buffering agent, and c) a nembrane selectively permeable to the unionized form of the drug and substantially impermeable to the ionized form of the drug and the buffer salts.
Claim 2
Dependent Claim
62 words
A transdermal delivery system suitable for administering a weakly acidic or basic drug which comprises a) a substantially impermeable backing member, b) a drug reservoir comprising the drug, a hydroxylated solvent and a buffering agent, and c) a nembrane selectively permeable to the unionized form of the drug and substantially impermeable to the ionized form of the drug and the buffer salts.
Claim 3
Dependent Claim
11 words
A system according to Claim 1 wherein the drug is timolol.
Claim 4
Dependent Claim
111 words
A transdermal delivery system for delivery of acidic or basic drugs comprising a) a backing member substantially impermeable to the drug, b) a drug reservoir adjacent to the backing member comprising the drug dispersed in a carrier, said carrier being permeable to the drug, and c) a membrane selectively permeable to the unionized form of the drug; wherein the concentration of the drug in the unionized form, C, and the membrane thickness, h, is related in a manner to provide a flux, J, in accordance with the equation wherein K is the partition coefficient between the drug reservoir and the membrane and D is the drug diffusion coefficient in the membrane.
Claim 5
Dependent Claim
111 words
A transdermal delivery system for delivery of acidic or basic drugs comprising a) a backing member substantially impermeable to the drug, b) a drug reservoir adjacent to the backing member comprising the drug dispersed in a carrier, said carrier being permeable to the drug, and c) a membrane selectively permeable to the unionized form of the drug; wherein the concentration of the drug in the unionized form, C, and the membrane thickness, h, is related in a manner to provide a flux, J, in accordance with the equation wherein K is the partition coefficient between the drug reservoir and the membrane and D is the drug diffusion coefficient in the membrane.
Claim 6
Dependent Claim
82 words
A transdermal delivery system for delivery of acidic or basic drugs comprising a) a substantially impermeable backing member, b) a drug reservoir adjacent to the backing member comprising the drug in a pH controlled buffer system, said system providing a pH environment controlling the concentration of the unionized basic or acidic form of the drug, and c) a membrane permeable to the passage of the drug in the unionized form and substantially impermeable to passage of the drug in the ionized form.
Claim 7
Dependent Claim
82 words
A transdermal delivery system for delivery of acidic or basic drugs comprising a) a substantially impermeable backing member, b) a drug reservoir adjacent to the backing member comprising the drug in a pH controlled buffer system, said system providing a pH environment controlling the concentration of the unionized basic or acidic form of the drug, and c) a membrane permeable to the passage of the drug in the unionized form and substantially impermeable to passage of the drug in the ionized form.
Claim 8
Dependent Claim
36 words
An improved transdermal bandage for delivery of basic or acidic drugs comprising a) an impermeable backing member b) a drug reservoir comprising a drug and a pH controlling reservoir vehicle, and c) a selectively permeable membrane.
Claim 9
Dependent Claim
36 words
An improved transdermal bandage for delivery of basic or acidic drugs comprising a) an impermeable backing member b) a drug reservoir comprising a drug and a pH controlling reservoir vehicle, and c) a selectively permeable membrane.
Claim 10
Dependent Claim
28 words
A bandage according to Claim 5 which has, in addition, an adhesive coating along the surface of the selectively permeable membrane for attachment to the skin or mucosa.
Claim 11
Dependent Claim
11 words
A system according to Claim 1 wherein the drug is sulindac.
References Cited (Backward Citations)
No citation records indexed.
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