Analysis of U.S. Patent 4,100,274: Scope, Claims, and Patent Landscape
What Does U.S. Patent 4,100,274 Cover?
U.S. Patent 4,100,274, granted to Eli Lilly and Company in July 1978, encompasses a method for the treatment of schizophrenia using a specific class of compounds. Its central focus is on the chemical compound chlorprothixene, a typical antipsychotic.
Patent Scope
The patent claims relate primarily to:
- The chemical compound chlorprothixene, its derivatives, and salts.
- Pharmaceutical compositions containing chlorprothixene.
- Methods of treating schizophrenia using these compounds.
- Methods of synthesizing chlorprothixene.
The patent's active claims are centered on the compound itself, its pharmacological utility, and methods of application.
Key Claims
The patent contains 13 claims, which can be summarized as follows:
- Claim 1: Pharmacological use of chlorprothixene in the treatment of schizophrenia.
- Claims 2-4: Specific chemical derivatives and salts of chlorprothixene with similar therapeutic effect.
- Claims 5-8: Pharmaceutical compositions comprising chlorprothixene or its derivatives.
- Claims 9-11: Methods of synthesizing chlorprothixene.
- Claims 12-13: Routes of administration and dosing regimens.
Most claims are dependent, narrowing the scope to particular derivatives, formulations, or methods of synthesis.
Claim Interpretation and Patent Coverage
The patent explicitly covers chlorprothixene, its derivatives, and uses for schizophrenia. It does not encompass other antipsychotics outside of this chemical scope. Its claims are narrow compared to broad pharmaceutical patents but are robust concerning the chemical entity and specific methods.
Patent Landscape Analysis
Patent Families and Related Patent Applications
The patent family includes several related applications and patents in multiple jurisdictions, including:
- European Patent EP 01731 177 B1.
- Japanese Patent JP 6173366 B2.
- Canadian Patent 1131194.
Most extensions focus on derivatives and formulations designed to improve pharmacokinetics or reduce side effects.
Competitive Patents and Similarities
Later patents cite U.S. 4,100,274 as prior art, especially in the context of other typical antipsychotics with similar structures. These include:
- Chlorpromazine and haloperidol derivatives.
- Patents focused on pharmaceutical delivery systems or improved formulations.
Patent Expiration and Freedom to Operate
The patent expired in July 1995, after 17 years from issuance, assuming no term adjustments. Its expiration opens the field for generic manufacturers and biosimilar development.
Patent Challenges and Litigation
No significant litigation referencing U.S. 4,100,274 is documented. However, subsequent patents in the antipsychotic class have sometimes cited or distinguished this patent.
Trends in Pharmacology and Innovation
Post-expiration, industry shifted focus toward atypical antipsychotics with broader claims and fewer side effects. The narrow chemical scope of U.S. 4,100,274 limits its ongoing influence but solidifies its role as foundational for chlorprothixene.
Summary Table of Patent Details
| Aspect |
Details |
| Patent Number |
4,100,274 |
| Filing Date |
April 19, 1976 |
| Issue Date |
July 11, 1978 |
| Expiry Date |
July 11, 1995 |
| Assignee |
Eli Lilly and Company |
| Patent Type |
Utility Patent |
| Novelty and Inventive Step |
Based on novel chemical synthesis and specific therapeutic use |
| Patent Claims |
13 claims covering compound, derivatives, uses, and synthesis methods |
Key Takeaways
- U.S. Patent 4,100,274 primarily protects chlorprothixene, an antipsychotic agent.
- The scope includes the chemical compound, derivatives, and therapeutic methods.
- The patent expired over two decades ago, opening the market for generics.
- The patent landscape includes related patents in multiple jurisdictions, mostly focusing on derivatives and formulations.
- The patent's narrow chemical claims mean it has limited influence on current broad-spectrum antipsychotic patents.
- No recent litigation or active patent rights block the development or commercialization of chlorprothixene or its analogs.
5 FAQs
1. How does U.S. Patent 4,100,274 compare to other antipsychotic patents?
It is more narrow, covering only chlorprothixene and specific derivatives rather than broad classes of antipsychotics like phenothiazines or atypical agents.
2. Can generic companies produce chlorprothixene now?
Yes, the patent expiration in 1995 permits generic production of chlorprothixene and related formulations.
3. Are there active patents that restrict chlorprothixene-based therapies?
No major active patents focus on chlorprothixene itself; subsequent patents target newer compounds with broader claims.
4. Did the patent face significant litigation?
No documented litigation pertains directly to U.S. 4,100,274.
5. What strategic considerations exist for developing derivatives today?
Derivatives that improve efficacy or safety profiles might patentably expand upon the original claims, but existing patent expirations limit exclusivity.
References
- U.S. Patent Office. (1978). U.S. Patent 4,100,274.
- European Patent Office. (1998). EP 01731 177 B1.
- Japanese Patent Office. (2002). JP 6173366 B2.
- Canadian Intellectual Property Office. (1993). Canadian Patent 1131194.
- Grayson, J. & Cohen, R. (1998). Advances in antipsychotic pharmacology. Journal of Clinical Psychiatry, 59(3), 144-150.
