EP0197504A2 — pH-mediated drug delivery system
Assigned to Merck and Co Inc · Expires 1986-10-15 · 40y expired
What this patent protects
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…
USPTO 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.
Drugs covered by this patent
Bibliographic data sourced from FDA Orange Book + USPTO public records. Plain-English summary generated by AI grounded in source text. Patent term extensions (PTR, SPC, pediatric) may shift the effective expiry. Not legal advice.
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