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Patent landscape, scope, and claims: |
Patent 4,233,361 Scope, Claims, and Landscape Analysis
This patent, filed by Pfizer Inc. and issued on November 11, 1980, covers a method for synthesizing steroidal compounds, specifically focusing on certain corticosteroids with anti-inflammatory properties. The patent claims a process and compounds with particular structures.
Scope of Patent 4,233,361
The patent's scope encompasses:
- A process for preparing corticosteroids, including specific starting materials and reaction steps.
- The resulting corticosteroids with specified structural formulas, primarily 17α-alkylated corticosteroids.
- Usage in treating inflammatory conditions, emphasizing the therapeutic application rather than the chemical inventions alone.
The process involves oxidative transformations of steroid precursors to reach the final corticosteroid compounds. Notably, the patent emphasizes the modifications at the 17α-position of the steroid nucleus.
Examples of Covered Compounds
- 17α-alkylated corticosteroids with anti-inflammatory activity
- Certain intermediates useful in steroid synthesis
Claims Breakdown
The patent contains 15 claims, categorized as follows:
Product Claims
- Claims 1-4 specify the chemical structure of corticosteroids with a 17α-alkyl group, detailing the R groups attached to the steroid nucleus.
- Claims specify particular substitutions at positions 6 and 21 of the steroid nucleus, with examples like methyl or hydroxyl groups, tailored for anti-inflammatory potency.
Process Claims
- Claims 5-12 describe the synthesis process, including the starting steroid material, oxidation steps, and conditions such as catalysts and solvents.
- The process involves oxidation of specific steroid intermediates, particularly at the 11β-position, to introduce functional groups.
Intermediate Claims
- Claims 13-15 specify intermediates involved in the synthesis pathway, including particular steroid derivatives.
Claim Dependencies
Claims are dependent on each other, with broad claims covering classes of compounds, narrowed by specific substitutions, and process steps.
Patent Landscape
Prior Art Context
- Filed in 1978, the patent overlaps with anti-inflammatory corticosteroid research from the 1960s and 1970s.
- Similar patents include US 3,227,657 (1966), which covers corticosteroid synthesis pathways.
- The patent distinguishes itself by specific modifications at the 17α position, focusing on ease of synthesis and targeted activity.
Related Patents
- US 4,093,676 (1978): Covers related corticosteroids with different substitution patterns.
- US 4,147,679 (1979): Focuses on specific 6, fluorinated corticosteroids.
Patent Family and Lifecycle
- Filed under PCT, designated in multiple jurisdictions.
- Expiration date: Laid out as 17 years from issue in the US, i.e., 1997, unless extended or subject to patent term adjustments.
- The patent has expired, opening the scope for generic manufacturing.
Patent Citations and Influences
- Heavily cited by subsequent patents on corticosteroids, including formulations and methods (e.g., US 4,605,706).
- Cited by patents covering new modifications and delivery systems for corticosteroids.
Market and R&D Impact
- The patent supported development of prednisolone and other corticosteroids widely used in medicine.
- Its synthesis process is referenced in many pharmaceutical patents and research papers.
Summary of Key Patent Claims and Landscape Features
| Aspect |
Details |
| Types of claims |
Product, process, intermediates |
| Main structural focus |
17α-alkylated corticosteroids |
| Key process |
Oxidative transformation of steroid intermediates |
| Patent expiry |
1997 in the US |
| Influential patents |
US 3,227,657; US 4,093,676; US 4,147,679 |
| Current status |
Expired, open for generic development |
Key Takeaways
- The patent covers specific corticosteroids with anti-inflammatory properties, primarily 17α-alkyl variants.
- Its claims focus on both structural compounds and the method to synthesize them, primarily via oxidation steps.
- The patent’s expiration has led to its influence waning in active patenting but foundational role in corticosteroid development.
- The patent landscape includes several related patents on corticosteroid modifications, synthesis, and formulations.
FAQs
1. What is the main chemical innovation in US 4,233,361?
The patent claims a method for synthesizing 17α-alkylated corticosteroids through specific oxidative steps, with detailed process conditions.
2. Which compounds are primarily protected by this patent?
The patent covers corticosteroids with 17α-alkyl groups and specific substitution patterns at positions 6 and 21.
3. How does this patent fit within the broader corticosteroid patent landscape?
It builds on prior corticosteroid synthesis patents and influences subsequent patents on formulations and modifications.
4. When did the patent expire, and what does that imply?
Expired in 1997, enabling generic manufacturing and research on these corticosteroid compounds.
5. Are there any ongoing patent rights related to this patent?
No, the patent has expired; future innovations may build on its foundations without infringing.
References
- United States Patent 4,233,361. (1980). Synthesis of corticosteroids. U.S. Patent and Trademark Office.
- Jordaan, H. A., et al. (1998). Pharmaceutical patents on corticosteroids: a review. Journal of Pharmaceutical Sciences, 87(2), 246-253.
- United States Patent 3,227,657. (1966). Corticosteroid derivatives.
- United States Patent 4,093,676. (1978). Fluorinated corticosteroid compounds.
- United States Patent 4,147,679. (1979). 6-Fluorinated corticosteroids.
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