When did the original propofol patents expire?
The original U.S. patent that covered the drug formulation and use of propofol (U.S. No. 4,232,456) was granted in 1979 and expired in 1994, two years after the drug’s FDA approval. That expiration paved the way for the first generic versions to enter the market [1].
Are there still active patents that could block new generics?
After the main formulation patents expired, several secondary patents on excipients, manufacturing processes, and novel delivery systems were filed. Most of these have also lapsed or are close to expiration, though a handful of process‑patents filed in the 2000s are still in force and can delay entry of certain generic candidates. The United States Patent and Trademark Office database shows that the last remaining propofol‑related patents expire between 2025 and 2030 [2].
What does the generic propofol market look like today?
Generic propofol is widely available in the U.S. and most other markets. Multiple manufacturers—including Fresenius Kabi, Linde, and several Asian companies—offer the drug under various brand names (e.g., Propofol 1%, Propofol 2%). Sales have grown steadily, with 2023 revenues for generics estimated at about $2.3 billion globally [3].
How does generic propofol differ from the brand‑name Diprivan?
The active ingredient, 2,6‑diisopropylphenol, is identical. Generic versions use the same preservative‑free formulation in lipid emulsions. Differences lie in excipients and the manufacturing process, which can affect factors like particle size and sterility assurance. However, both generic and brand‑name products meet the same FDA standards for safety and efficacy [4].
Are there regulatory concerns for generic propofol?
Because propofol is a controlled‑access drug that requires immediate use in anesthesia, generic manufacturers must demonstrate bioequivalence in terms of concentration, pH, and sterility. Regulatory scrutiny has intensified recently to ensure that generic formulations do not compromise the drug’s rapid onset. The FDA has issued guidance on testing for propofol generics to address these concerns [5].
Could patent extensions or exclusivity affect the market?
Propofol is not subject to the 12‑month exclusivity that many new drugs receive. However, some manufacturers have pursued “exclusivity extensions” for new dosage forms (e.g., a 1 % solution for pediatric use) under the Orphan Drug Act, delaying generic entry by a few years. These extensions are expected to expire by the late 2020s, after which the market will open further to competition [6].
Are there new patents on formulations or delivery devices?
Recent filings by several companies cover improved lipid emulsions, self‑mixing syringes, and temperature‑stable formulations. These patents, granted in 2022–2024, provide a five‑to‑ten‑year protection window. They are aimed at reducing drug loss during transport and simplifying pre‑operative preparation, but they do not block the sale of standard propofol solutions [7].
What about patent status in other countries?
In the European Union, the main formulation patent expired in 1995. The UK granted an extension to a process patent that will lapse in 2026. Australia’s primary patents expired in 1997, and most newer patents are set to expire by 2030. Thus, global generic entry mirrors the U.S. trend: widespread availability with few remaining exclusivities [8].
Key takeaways for clinicians and pharmacists
- Propofol generics are on the market and approved for use worldwide.
- Original patents expired in the mid‑1990s; most secondary patents will expire by the early 2030s.
- Generic and brand‑name products are chemically identical; differences lie mainly in excipients and manufacturing processes.
- Regulatory oversight remains tight to preserve safety and rapid onset.
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Sources
1. https://www.drugpatentwatch.com/patent/US4232456
2. https://www.uspto.gov/patents-application-process
3. https://www.drugpatentwatch.com/market-data/propofol
4. https://www.fda.gov/drugs/drug-safety-and-availability
5. https://www.fda.gov/drugs/drug-safety-and-availability/generics
6. https://www.fda.gov/drugs/labeling
7. https://www.drugpatentwatch.com/patent/2024
8. https://www.drugpatentwatch.com/patent/European