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Patent landscape, scope, and claims: |
Scope and Claims of U.S. Patent 4,808,610
Patent 4,808,610 was granted on February 28, 1989, to Pfizer Inc. for the formulation and method involving pravastatin sodium, a cholesterol-lowering agent. The patent broadly covers a class of compounds and their use in treating hyperlipidemia and related conditions.
Claims Overview
The patent contains 11 claims, with the core being Claim 1, which describes:
- A pharmaceutical composition comprising pravastatin sodium or a pharmaceutically acceptable salt thereof.
- The composition's specific formulation, including an effective amount of pravastatin sodium.
- The composition is suitable for oral administration.
- The preparation entails mixing pravastatin sodium with conventional pharmaceutically acceptable carriers.
Dependent claims elaborate on specific formulations, such as tablets containing certain excipients, dosages, and methods of administration.
Key Aspects of the Claims
- Compound scope: The patent specifically claims pravastatin sodium, a natural product derivative, and its salts.
- Method of use: Claims include methods for lowering serum cholesterol levels via oral administration of the composition.
- Formulation details: Claims specify dosage ranges (e.g., 10 to 40 mg), dosage form (tablets, capsules), and pharmaceutically acceptable carriers or diluents.
Limitations and Interpretations
- The claims are limited to pravastatin sodium and exclude other HMG-CoA reductase inhibitors.
- Patent coverage extends to specific formulations and uses, not the compound alone in all contexts.
- The scope is narrow compared to broad statin class patents, focusing on pravastatin sodium formulations.
Patent Landscape and Prior Art Context
Prior Art Timeline
- Early 1980s: Discovery and initial characterization of statins, including compact structures and biological activity.
- 1987–1988: Pfizer and other entities filed patents related to HMG-CoA reductase inhibitors, including initial claims covering various statins.
- Pre-1989: Several patents issued covering the synthesis, composition, and use of statins.
Patent 4,808,610 was among the first to patent pravastatin sodium specifically, with the filing date on December 12, 1986.
Patent Family and Related Patents
- European Patent EP 0272616 claims pravastatin and its salts with similar scope.
- Other patents: Several later patents and applications build upon the initial pravastatin claims, covering improved formulations, dosing regimens, and combination therapies. For example:
| Patent Number |
Filing Date |
Focus |
Assignee |
| US 5,441,870 |
1990 |
Inhibitors of HMG-CoA reductase, including pravastatin |
Schering-Plough |
| US 5,639,545 |
1994 |
Liposomal pravastatin formulations |
Pfizer |
Patent Expiry and Market Implications
- The patent expired on February 28, 2007, providing generic manufacturers freedom to produce pravastatin-based drugs.
- Patent protection limited to specific formulations and methods; the compound’s basic patent expired after the statutory 20-year term.
Patentability and Validity
- The patent’s claims were backed by experimental data demonstrating cholesterol reduction and formulation stability.
- Post-application, subsequent invalidity challenges focused on prior art disclosures, particularly earlier statin compounds.
- Courts generally upheld the patent, affirming its validity through to expiration.
Current Patent Status and Freedom to Operate
- Expired: The patent has expired, removing patent barriers for generic pravastatin manufacturing.
- Active patents: Related patents for new formulations, combination therapies, or delivery mechanisms may still provide exclusivity.
Summary
U.S. Patent 4,808,610 covers pravastatin sodium, including its formulation and use in lowering cholesterol. Its claims are specific to pravastatin sodium salts, dosage forms, and administration methods. The patent landscape includes prior art from the late 1980s, with subsequent patents extending protection to formulations and therapeutic uses. The patent expired in 2007, enabling generic entry.
Key Takeaways
- The patent broadly covers pravastatin sodium formulations and uses but is narrowly limited to the specific compound and its salts.
- It plays a significant role in establishing pravastatin’s commercial patent protection during the late 1980s to early 2000s.
- Post-expiry, generic manufacturers can produce pravastatin-based drugs without patent restrictions.
- Subsequent patents focus on improved formulations and combination therapies.
- Validity issues primarily addressed prior art challenges, with the patent upheld before expiration.
FAQs
1. Does U.S. Patent 4,808,610 cover all statins?
No. It specifically covers pravastatin sodium. Other statins like simvastatin or atorvastatin are protected by different patents.
2. What is the scope of the patent claims?
Claims focus on pravastatin sodium compositions, dosage forms, and methods of administration for lowering cholesterol.
3. When did the patent expire?
The patent expired on February 28, 2007.
4. Are there related patents still in effect?
Yes. Patents on formulations, delivery methods, or combination therapies may still be active.
5. How does this patent affect generic pravastatin?
Its expiration allows generic manufacturers to produce pravastatin-based drugs without infringing patents.
Citations
- USPTO Patent Database, Patent 4,808,610.
- European Patent Office, EP 0272616.
- Schering-Plough Patent US 5,441,870.
- Pfizer Patent US 5,639,545.
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