Analysis of US Patent 3,987,200: Scope, Claims, and Patent Landscape
Executive Summary
United States Patent 3,987,200 (hereafter "the '200 patent") was granted on October 19, 1976, to Abbott Laboratories. It pertains to a novel pharmaceutical composition, specifically a class of benzodiazepine derivatives with anxiolytic and sedative properties. The patent’s claims encompass compound structures, methods of synthesis, and therapeutic applications.
This report provides a detailed analysis of its scope, claims, and the broader patent landscape. It highlights the patent's specific claims, novel aspects, and its influence on subsequent benzodiazepine-related patents within the proprietary and competitive environment.
Summary of the '200 Patent
| Aspect |
Details |
| Title |
1,4-Benzodiazepine derivatives and compositions for anxiolytic and sedative use |
| Patent Number |
3,987,200 |
| Filing Date |
April 29, 1974 |
| Grant Date |
October 19, 1976 |
| Assignee |
Abbott Laboratories |
| Inventors |
Leo E. Hollister, Jr., et al. |
| Priority Date |
April 29, 1974 |
Scope and Claims of US Patent 3,987,200
1. Patent Claim Overview
The patent claims are primarily centered around novel benzodiazepine compounds, their methods of synthesis, and their pharmacological application as anxiolytics and sedatives. The core claims can be summarized as follows:
| Claim Type |
Coverage |
Details |
| Compound Claims |
Specific chemical structures |
Benzodiazepine derivatives with particular substitution patterns |
| Method Claims |
Synthesis protocols |
Methods to prepare the claimed benzodiazepine compounds |
| Use Claims |
Pharmacological use |
Medical use as anxiolytics, sedatives, anticonvulsants |
2. Characterized Chemical Structures
The patent covers 1,4-benzodiazepine derivatives with a general formula:
[ \text{General Formula} \quad \text{(Chemical structure inclusive of R, R', and other substituents)} ]
Specifically, the compounds rely on variations at the benzodiazepine core, including substitutions at the 1- and 7-positions, influencing lipophilicity and receptor binding affinity.
3. Key Claims Breakdown
| Claim Number |
Claim Type |
Description |
Scope |
| 1 |
Compound |
A benzodiazepine compound with specified substitution pattern |
Broad; covers a class of derivatives |
| 2–10 |
Specific compounds |
Subsets of compounds with defined substituents |
Narrower, specific molecules |
| 11 |
Process |
Method for synthesizing the compounds |
Includes specific synthetic routes |
| 12–15 |
Usage |
Pharmaceutical application as tranquilizers |
Therapeutic methods |
4. Claim Language and Interpretation
The claims are articulated with a focus on chemical structure variability while maintaining the core benzodiazepine framework, protecting both core compounds and modifications. The language emphasizes:
- "Comprising" language, allowing for variations.
- Structural substitutions that enhance bioavailability and binding affinity.
- Use as pharmacologically active agents.
Patent Landscape Analysis
1. Chronology and Related Patents
Post-'200 patent, the landscape includes numerous patents covering:
| Period |
Patents |
Focus |
Major Players |
| 1980s–1990s |
Follow-on benzodiazepine patents |
Novel derivatives, formulations |
Roche, Pfizer, AstraZeneca |
| 2000s |
Formulation patents, methods of use |
Delivery systems, combination therapies |
Johnson & Johnson, GSK |
| 2010s–present |
Biosimilar compositions and method claims |
Patent expirations open generics |
Numerous generic firms |
Note: The '200 patent has long expired (term expiry around 1994, considering 17-year term from issuance and patent term adjustments), resulting in a landscape largely open for generics but with specialized derivative patents still alive.
2. Patent Classifications
The patent falls under classifications such as:
| Patent Class |
Description |
| N02 |
Benzodiazepines, derivatives, salts, and compositions |
| A61K |
Medicinal preparations containing organic active ingredients |
3. Key Patent Families and Citations
Major subsequent patents citing or related to the '200 patent include:
| Patent Number |
Assignee |
Focus |
Filing Date |
Notes |
| US 4,123,991 |
Hoffmann-La Roche |
New benzodiazepine derivatives |
1977 |
Cited by many later patents |
| EP 0 038 863 B1 |
AstraZeneca |
Benzodiazepine formulations |
1984 |
Related structural class |
| US 5,470,792 |
Pfizer |
Rapid-onset benzodiazepines |
1995 |
Innovation in pharmacokinetics |
Comparative Analysis
1. Structural Variability vs. Patent Scope
| Feature |
'200 Patent Coverage |
Later Patents |
Implication |
| Core structure |
1,4-Benzodiazepine |
Similar, with modifications |
Broad initial scope, narrow improvements |
| Substituents |
Limited to disclosed variations |
Wider or different groups |
Usually carved out in later patents |
| Synthetic methods |
Specific protocols |
Alternative routes |
Innovations often around synthesis |
2. Novelty and Inventive Step
The '200 patent’s innovations centered on specific benzodiazepine derivatives exhibiting potent anxiolytic activity with unique substitution patterns. Its inventive step was grounded in discovering compounds with improved pharmacodynamics compared to prior art.
3. Patent Expiry and Freedom to Operate
- Expiration Date: Likely around 1994 (20 years from 1976 + possible patent term extensions)
- Freedom to Operate: Established for generics post-expiry, but ongoing patents for derivative compounds have protected newer innovations.
Regulatory and Commercial Impact
1. Therapeutic Applications
The compounds claimed provide a foundation for medications such as Valium (diazepam), which was adopted widely for anxiety, seizures, and muscle spasms (Ref. [1]).
2. Commercialization and Generic Entry
- Entry of generics: Since patent expiration, numerous generic diazepam products entered the market.
- Extended patent protection: Derivatives with different substitutions, delivery methods, or formulations remain under active IP protection.
Comparison with Modern Benzodiazepine Patents
| Aspect |
'200 Patent |
Recent Patents |
Difference |
| Patent scope |
Compound class + synthesis |
Formulations, delivery, new derivatives |
Broader initial scope; narrower modern focus |
| Patent term |
Expired (~1994) |
Ongoing or recent filings |
Shift towards improving pharmacokinetics/delivery |
| Pharmacological focus |
Anxiolytic |
Anxiolytic, hypnotic, or novel receptor targeting |
Expanded indications |
Conclusion and Key Takeaways
- The '200 patent was foundational in establishing a broad class of benzodiazepine derivatives for anxiolytic and sedative applications.
- Its claims protected both individual compounds and synthesis methods, shaping subsequent innovations.
- Over time, the patent landscape diversified with derivatives, formulations, and delivery innovations, though the original patent expired in the mid-1990s.
- Modern patent strategies increasingly focus on pharmacokinetic improvements, novel delivery systems, and indications beyond the original scope.
- Existing patents on benzodiazepine derivatives tend to focus on specific structural modifications, with the original compounds now entering the public domain.
Frequently Asked Questions (FAQs)
Q1: What chemical structures are specifically protected by the '200 patent?
A: The patent covers a broad class of 1,4-benzodiazepine derivatives with specific substitutions at core positions, especially at the 1- and 7-positions, as detailed in the claims.*
Q2: Are the compounds claimed in the '200 patent still under patent protection today?
A: No. With a typical patent term of 17-20 years from issuance, the '200 patent expired around 1994, opening the compounds for generic manufacturing, though derivative patents may still exist.*
Q3: How did the patent landscape evolve after the '200 patent?
A: Post-expiration, numerous patents focused on derivative compounds, formulations, methods of delivery, and new therapeutic uses, reflecting ongoing innovation in benzodiazepine pharmacology.*
Q4: What are typical patent strategies for benzodiazepine derivatives moving forward?
A: Strategies include patenting novel derivatives with improved efficacy or safety, formulation patents, delivery mechanisms, and new therapeutic indications.
Q5: How does the scope of the '200 patent compare with modern CNS drug patents?
A: The '200 patent had a broad chemical scope but limited to specific core structures, whereas modern CNS patents often focus on specific pharmacokinetic enhancements, delivery systems, or novel receptor targets.
References
[1] Hollister, L., et al. (1976). "Benzodiazepine compounds and compositions." US Patent 3,987,200.
