Antizol generics — when can they launch?
Antizol (FOMEPIZOLE) · Par Pharm Inc · 1 active US patent · 0 expired
Where Antizol sits in the generic timeline
Imminent generic cliff: earliest active US patent for Antizol expires in 2027 (~1 year 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.
- Composition of Matter — 1 patent
Sample patent estate
Showing 1 of 1 active US patents. View full estate on the Antizol drug page →
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This patent protects a novel process for producing ultrapure 4-methylpyrazole with specific impurity levels.USPTO title: Ultrapure 4-methylpyrazole
Sources
- FDA Orange Book — patents listed against Antizol (NDA filed 1997)
- Antizol drug profile — full patent estate, indications, clinical trials, pricing
- Par Pharm Inc patent portfolio
- Patent cliff 2027 — every drug losing US exclusivity that year
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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