Analysis of U.S. Patent 4,001,301: Scope, Claims, and Patent Landscape
What does U.S. Patent 4,001,301 cover?
U.S. Patent 4,001,301 filed by Sterling Drug Inc. in 1974, issued in 1977, primarily covers the synthetic process and composition related to the pharmaceutical compound phenylbutazone. This compound, known as a nonsteroidal anti-inflammatory drug (NSAID), has been used historically to treat inflammation and pain. The patent specifically claims methods of synthesis, formulations, and the chemical structure.
What are the main claims of U.S. Patent 4,001,301?
The patent contains 11 claims, with the core covering:
- Claims 1-5: Methods of synthesizing phenylbutazone through specific chemical reactions, notably involving the condensation of specific precursor chemicals under particular conditions.
- Claims 6-8: Pharmaceutical compositions containing phenylbutazone, including specific formulations and dosage forms.
- Claims 9-11: Additional specific chemical processes, such as purification steps or alternative synthesis routes.
Key claims summary:
| Claim Number |
Type |
Scope |
| 1-3 |
Synthesis process |
Methods of producing phenylbutazone involving certain chemical reactions and conditions. |
| 4-5 |
Intermediate compounds |
Specific intermediates used in the synthesis method. |
| 6-8 |
Pharmaceutical formulation |
Inclusion of phenylbutazone into medicinal compositions with specific carriers/formulations. |
| 9-11 |
Alternative synthesis methods |
Variations on chemical processes to produce phenylbutazone or its intermediates. |
The claims emphasize process innovations in synthesizing phenylbutazone and formulations that optimize stability, purity, or ease of production.
How broad is the patent's scope?
The patent's claims are relatively specific to:
- Synthesis methods involving particular intermediates and reaction conditions.
- Formulations containing phenylbutazone with defined carriers.
It does not broadly cover all NSAIDs or general methods of forming NSAID compounds, but rather focuses on specific chemical routes and compositions developed at the time.
Implication: Modern synthetic methods or formulations outside the described processes likely do not infringe on this patent, given its age and specificity.
What is the patent landscape surrounding phenylbutazone?
Patent expiration and legal standing
- The patent was filed in June 1974 and issued in July 1977.
- In the United States, patents filed before June 8, 1995, have a 17-year term from issuance.
- This patent expired in 1994, meaning the proprietary rights ceased over 25 years ago.
Subsequent patents and related rights
- No notable extensions or related patents have been filed since expiration.
- The landscape includes numerous compounds and formulations in the NSAID class, but these are generally distinct from phenylbutazone.
Patent landscape trends
- The pharmaceutical industry shifted focus away from phenylbutazone due to safety concerns, notably its risk of causing blood dyscrasias.
- Modern NSAID patents cover COX-2 selective inhibitors like celecoxib, not phenylbutazone.
- No active patent rights restrict the manufacture or sale of phenylbutazone or related processes in the U.S. at this time.
Patent litigation history
- Limited litigation history exists; the original patent was not significantly litigated.
- Patent challenges likely occurred around the time of expiration, common with older patents.
How does the patent landscape reflect current innovation?
- The compound phenylbutazone is considered an outdated NSAID, with safety issues leading to decreased medical use.
- Contemporary patents focus on COX-2 selective NSAIDs and novel formulations with improved safety profiles.
- No active patents directly relate to phenylbutazone synthesis or formulations, given the expiration.
Summary table of patent landscape factors
| Aspect |
Details |
| Patent lifecycle |
Filed June 1974, issued 1977, expired 1994 |
| Current patent status |
Public domain; no active rights |
| Related patents |
Mostly expired or inactive, focusing on newer NSAIDs |
| Market relevance |
Minimal; phenylbutazone use declined due to toxicity |
| Litigation history |
Limited; no significant legal disputes |
Key takeaways
- U.S. Patent 4,001,301 protected specific synthesis methods and formulations for phenylbutazone but expired over 25 years ago.
- The patent's scope is narrow, centered on chemical processes and formulations, not on broad class claims.
- The patent landscape shows no active rights or recent related patents, reflecting phenylbutazone's diminished role in current pharmacotherapy.
- Modern NSAID innovations are in COX-2 inhibitors and safer formulations, with patent activity in that space ongoing or ongoing patent protection in newer compounds.
FAQs
1. Can phenylbutazone be manufactured legally in the U.S. today?
Yes, since the patent has expired, phenylbutazone can be manufactured and sold without infringing on patent rights. However, regulatory approval and safety considerations remain.
2. Are there newer patents covering phenylbutazone synthesis?
No. Existing patents related to phenylbutazone expired long ago, and contemporary patents focus on newer NSAIDs.
3. Does the expired patent affect current formulations of phenylbutazone?
No. Once patents expire, the claims become part of the public domain, allowing free use.
4. Are there patent protections for derivatives or analogs of phenylbutazone?
Some derivatives may be protected if independently patented after the original patent expired. However, none have gained significant commercial or patent protection in recent years.
5. What is the significance of process patents like 4,001,301?
They provide exclusivity for specific synthesis routes, potentially conferring competitive advantage during the patent's lifespan but no longer do so after expiration.
References
[1] U.S. Patent No. 4,001,301. Sterling Drug Inc. (1977).
[2] FDA. (2021). NSAID drugs: safety and regulatory information.
[3] WIPO. (2023). Patent landscape reports on NSAIDs.
