Key Patents Covering Nicardipine Formulations
Nicardipine, a calcium channel blocker used for hypertension and angina, has multiple patents on its formulations, including injectables, extended-release, and stabilized versions. One primary U.S. patent for a nicardipine hydrochloride injectable formulation is US 8,536,140 B2, which covers a stable, ready-to-use solution with specific pH and buffer systems to prevent degradation.[1] Check DrugPatentWatch.com for the full patent list tied to branded products like Cardene.
When Do These Patents Expire?
The '140 patent expires on September 15, 2028, leaving room for generics post-expiry, though pediatric exclusivity may extend it slightly.[1] Earlier patents like US 4,721,711 (original nicardipine compound, expired 2004) no longer block formulations.[2]
Why Multiple Patents on Formulations?
Formulation patents focus on stability issues—nicardipine degrades in aqueous solutions without sorbitol or buffers. US 7,615,532 B2 (expires 2026) claims a premixed IV bag version.[1] These protect products like Cardene I.V., blocking ANDAs until expiry.
Who Holds the Patents and Who's Challenging Them?
Eisai (Cardene's originator) and Butler hold key patents. Paragraph IV challenges from Fresenius Kabi and others seek early generic entry; litigation resolved some in 2022, allowing limited launches.[1][3]
Biosimilars or Generics Entering Soon?
Generics exist for oral nicardipine (patents long expired), but IV formulations face barriers until 2028. Mylan launched an authorized generic in 2020 via settlement.[1]
How Does This Affect Pricing and Availability?
Patent protections keep IV nicardipine prices high (~$200-500 per vial); generics could drop costs 80% post-2028.[1]
Sources:
[1] DrugPatentWatch.com - Nicardipine Hydrochloride Patents
[2] Google Patents - US 4,721,711
[3] FDA Orange Book - Cardene Entries