Generic entry timeline

Estrace generics — when can they launch?

Estrace (ESTRADIOL) · Pfizer · 101 active US patents · 1 expired

Earliest patent expiry
2028-07-10
2 years remaining
Full patent estate to
2042-11-05
complete protection through 2042
FDA approval
1975
Pfizer

Where Estrace sits in the generic timeline

Imminent generic cliff: earliest active US patent for Estrace expires in 2028 (~2 years from today). ANDA filers are likely already preparing Paragraph IV certifications. Expect first-filer 180-day exclusivity competition imminently.

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 — 57 patents
  • Formulation — 33 patents
  • Composition of Matter — 11 patents

FDA U-codes carved out by Estrace 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-2086(no description)
U-2439(no description)
U-2316(no description)
U-2317(no description)
U-3129(no description)
U-2360(no description)

Sample patent estate

Showing 6 of 101 active US patents. View full estate on the Estrace drug page →

  • US9833419 Formulation · expires 2028-07-10
    This patent protects a transdermal drug delivery system for administering estrogen, comprising a polymer matrix and estrogen.
    USPTO title: Transdermal estrogen device and delivery
  • US9833419 Formulation · expires 2028-07-10
    This patent protects a transdermal drug delivery system for administering estrogen, comprising a polymer matrix and estrogen.
    USPTO title: Transdermal estrogen device and delivery
  • US9730900 Method of Use · expires 2028-07-10
    This patent protects a method of using transdermal drug delivery systems for the administration of estrogen.
    USPTO title: Transdermal estrogen device and delivery
  • US9833419 Formulation · expires 2028-07-10
    This patent protects a transdermal drug delivery system for administering estrogen, comprising a polymer matrix and estrogen.
    USPTO title: Transdermal estrogen device and delivery
  • US9724310 Composition of Matter · expires 2028-07-10
    This patent protects a transdermal drug delivery system for administering estrogen, comprising a polymer matrix and estrogen.
    USPTO title: Transdermal estrogen device and delivery
  • US9833419 Formulation · expires 2028-07-10
    This patent protects a transdermal drug delivery system for administering estrogen, comprising a polymer matrix and estrogen.
    USPTO title: Transdermal estrogen device and delivery

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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