Generic entry timeline

DONEPEZIL HYDROCHLORIDE generics — when can they launch?

DONEPEZIL HYDROCHLORIDE (DONEPEZIL HYDROCHLORIDE) · · 35 active US patents · 0 expired

Earliest patent expiry
2026-10-04
expired
Full patent estate to
2038-08-11
complete protection through 2038
FDA approval
1996

Where DONEPEZIL HYDROCHLORIDE sits in the generic timeline

All listed Orange Book patents for DONEPEZIL HYDROCHLORIDE have expired. Generic entry is permitted, and ANDA filers can launch without patent infringement risk. Hatch-Waxman exclusivity (NCE/ODE/PED) may still apply if recently approved.

Under US Hatch-Waxman, a generic enters via an ANDA (Abbreviated New Drug Application) and may file with one of four Paragraph IV certifications attacking the brand's listed patents. If the brand sues within 45 days, a 30-month FDA approval stay is triggered. First Para IV filer typically gets 180-day market exclusivity.

Patent estate by type — active patents

Method-of-use patents only carve out specific indications; generics can launch with a "skinny label" omitting those uses. Composition-of-matter patents block the molecule itself.

  • Method of Use — 24 patents
  • Formulation — 7 patents
  • Other — 4 patents

FDA U-codes carved out by DONEPEZIL HYDROCHLORIDE patents

Method-of-use patents are listed against specific FDA Patent Use Codes ("U-codes") representing carved-out indications. Generics can launch with a label that omits these uses.

U-codeDescription
U-1641(no description)
U-3334(no description)

Sample patent estate

Showing 6 of 35 active US patents. View full estate on the DONEPEZIL HYDROCHLORIDE drug page →

  • US8481565 Formulation · expires 2026-10-04
    This patent protects a method for stabilizing an anti-dementia drug, specifically donepezil hydrochloride, in a pharmaceutical composition.
    USPTO title: Method for stabilizing anti-dementia drug
  • US8039009 Method of Use · expires 2029-03-24
    This patent protects modified release formulations of memantine oral dosage forms that sustain the release of the active agent for 4 to 24 hours.
    USPTO title: Modified release formulations of memantine oral dosage forms
  • US8039009 Method of Use · expires 2029-03-24
    This patent protects modified release formulations of memantine oral dosage forms that sustain the release of the active agent for 4 to 24 hours.
    USPTO title: Modified release formulations of memantine oral dosage forms
  • US8039009 Method of Use · expires 2029-03-24
    This patent protects modified release formulations of memantine oral dosage forms that sustain the release of the active agent for 4 to 24 hours.
    USPTO title: Modified release formulations of memantine oral dosage forms
  • US8039009 Method of Use · expires 2029-03-24
    This patent protects modified release formulations of memantine oral dosage forms that sustain the release of the active agent for 4 to 24 hours.
    USPTO title: Modified release formulations of memantine oral dosage forms
  • US8039009 Other · expires 2029-09-24
    This patent protects pharmaceutical compositions containing memantine or a memantine salt, sustained-release formulations that release the active agent over 4 to 24 hours.
    USPTO title: Modified release formulations of memantine oral dosage forms

Sources

Patent term extensions (PTR, pediatric exclusivity), Hatch-Waxman 30-month stays, and FDA regulatory exclusivity (NCE/ODE/PED) may shift the effective generic entry date. Not legal advice.

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