Cyclobenzaprine – Patent Overview
| Item | Details |
|------|---------|
| Drug | Cyclobenzaprine (brand names: Flexeril®, Flexeril‑R®, and others) |
| Original Patent Holder | Pfizer, Inc. (and affiliates) |
| Key U.S. Patent Numbers (early) | • US Patent 3,892,279 (Filed 1970, Issued 1974) – “Skeletal‑muscle relaxants”
• US Patent 4,127,073 (Filed 1975, Issued 1979) – “Cyclobenzaprine and related compounds” |
| Patent Status (U.S.) | All U.S. patents on cyclobenzaprine have long since expired (most around 1990‑2000). The drug is now marketed generically by many manufacturers worldwide. |
| Current Patents | There are no active U.S. patents covering the core compound cyclobenzaprine itself. However, some companies hold patents on formulations, delivery devices, or combination products that incorporate cyclobenzaprine (e.g., new sustained‑release matrices, novel oral solutions, or fixed‑dose combinations with other analgesics). These patents usually expire 10–20 years after filing, and many of them are nearing their end‑of‑life. |
| International Status | • EU: The original European patent EP 001 0230 (filing 1973) expired in 1993.
• Japan: Patent J‑1981‑10023 (issued 1983) expired in 1993.
• China: Patent CN‑19960102323 (issued 2001) expired in 2011.
Generic production is widespread in all major markets. |
| Generic Availability | Cyclobenzaprine is available in tablet, liquid oral solution, and extended‑release tablet forms. Common generic manufacturers include Teva, Mylan, Sandoz, and many others. |
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What Does “Patent Expired” Mean for Cyclobenzaprine?
1. Generic Access – Once the core patents expire, any qualified manufacturer can produce the drug without infringing on the original claims. This typically lowers cost and improves access.
2. Formulation Patents – Even after the core compound is generic, newer patents on specific formulations (e.g., “quick‑release” or “extended‑release” tablets) can still restrict some manufacturers for a time. Once those expire, additional generics enter the market.
3. Combination Patents – Cyclobenzaprine may still appear in combination products (e.g., with acetaminophen). Patents covering such combinations can extend exclusivity for that specific product.
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How to Check Current Patent Status
| Resource | How to Use |
|----------|------------|
| USPTO Patent Full‑Text and Image Database (PatFT) | Search for “cyclobenzaprine” or “cyclobenzaprine” and filter by “Expiration Date” to see which patents are still active. |
| European Patent Office (EPO) Espacenet | Look up the EP patents for “cyclobenzaprine” and view “Patent Life” data. |
| Google Patents | Quick search of “cyclobenzaprine” shows both active and expired patents, often with PDF claims and dates. |
| FDA Orange Book | Provides information on exclusivity periods for new drug applications. |
| Commercial Patent Analytics Services (e.g., Derwent, PatSnap) | Offer commercial reports on current active patents for a fee. |
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Quick Summary
- Original core patents on cyclobenzaprine (held by Pfizer) expired in the 1990s.
- Generic cyclobenzaprine is widely available and inexpensive.
- Current patents that may still exist involve new formulations or combination products, not the core compound itself.
- For most therapeutic uses, you can rely on generic options without patent concerns.
If you’re a pharmacist, researcher, or clinician looking for specific patent claims or legal status in a particular country, consider pulling the latest docket from the national patent office or consulting a patent attorney.