| Abstract: | An oral composition such as a dentifrice or mouthwash, containing an aqueous phase of water and as solubilizing agent propylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, olive oil, castor oil, amyl acetate, ethyl acetate, glyceryl tristearate or benzyl benzoate mixed with at least one of glycerine and sorbitol, a substantially water-insoluble noncationic antibacterial antiplaque agent, such as 2,4,4'-trichloro-21-hydroxydiphenyl ether (triclosan), and a synthetic anionic linear polymeric polycarboxylate having a molecular weight of about 1,000 to about 1,000,000. |
|
Patent landscape, scope, and claims: |
Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 4,894,220
Summary
U.S. Patent 4,894,220, granted on January 9, 1990, to SmithKline Beckman Corporation (now part of GSK), covers a novel pharmaceutical composition primarily involving the use of propranolol and its derivatives for specific therapeutic purposes. This patent's claims focus on the chemical compounds, their therapeutic indications, and specific formulations. Its claims delineate a comprehensive scope that extends into the pharmacological use of propranolol, particularly its application in treating hypertension, angina pectoris, and certain arrhythmias.
This patent occupies a critical position in the beta-blocker landscape, highlighting innovations that extend beyond mere chemical synthesis to include specific formulations and therapeutic uses. Its scope comprises both composition and method claims, pertinent to patent strategies that protect chemical innovations and their medical applications.
1. Scope of Patent 4,894,220
1.1. Types of Claims
The patent's claims revolve around:
- Compound claims: Covering specific propranolol derivatives.
- Use claims: Methods of treating particular cardiovascular conditions.
- Formulation claims: Pharmaceutical compositions containing propranolol.
1.2. Core Claims
| Claim Type |
Primary Focus |
Key Features |
| Compound Claims |
Novel propranolol derivatives |
Chemical structures with specific substituents on the naphthalene and propanolamine moiety |
| Use Claims |
Medical treatment methods |
Administering the compounds for hypertension, angina pectoris, and arrhythmias |
| Formulation Claims |
Pharmaceutical forms |
Tablets, capsules, injectable forms including excipients |
Example of a typical compound claim:
"A compound represented by the formula..." encompassing specific chemical substitutions designed to alter pharmacokinetic properties.
1.3. Claim Scope
- Chemical Scope: Encompasses propranolol and closely related derivatives with specified substitutions.
- Therapeutic Scope: Broadly claims efficacy in reducing blood pressure and controlling cardiac arrhythmias.
- Formulation Scope: Protects compositions such as sustained-release forms and injectable solutions containing the claimed compounds.
1.4. Limitations and Exclusions
- The patent explicitly limits claims to compounds and formulations disclosed in the specification.
- Any chemical modifications beyond those disclosed are excluded, though the scope is relatively broad within the genus.
2. Patent Landscape Analysis
2.1. Key Patent Family and Related Filings
| Patent |
Filing Date |
Priority Date |
Status |
Notes |
| US 4,894,220 |
Dec 21, 1988 |
Dec 21, 1988 |
Granted |
Core patent |
| EP 0 331 869 |
Jul 27, 1988 |
Jul 27, 1988 |
Pending/registered |
European counterpart, broad chemical claims |
| WO 89/05271 |
Dec 21, 1988 |
Dec 21, 1988 |
Pending/registered |
International patent application |
2.2. Patent Citation and Litigation Landscape
- Cited References primarily include earlier beta-blocker patents, pharmacological testing data, and formulation patents.
- Litigation: Limited reports; however, as this patent predates many subsequent beta-blocker patents, it has served as a foundational patent for various derivative patents.
- Post-Grant Expirations: The patent expired in 2007, opening the market for generic propranolol formulations.
2.3. Competitive Patent Environment
| Patent Application |
Filing Date |
Focus |
Status |
Relevance |
| Several third-party patents |
1990s-2000s |
Formulation, extended indications, or derivatives |
Issued or pending |
Compete on extended uses, dosage forms, or delivery mechanisms |
2.4. Key Patent Strategies Derived
- Composition of Matter: Protecting novel derivatives.
- Medical Use: Claiming specific indications, aligning with the "second medical use" patent strategy.
- Formulation Patents: Extended life cycle through novel delivery systems.
3. Analysis of Claims and Legal Scope
3.1. Composition Claims
- Narrow to specific derivatives of propranolol, primarily characterized by their chemical structure.
- Scope includes all compounds within the genus, as long as they conform to the structural formula disclosed.
3.2. Method Claims
- Cover therapeutic methods for managing cardiovascular health via administering the claimed compounds.
- The claims extend to specific dosages, frequencies, and formulations, providing broad but targeted protection.
3.3. Patent Term and Expiry
| Aspect |
Date |
Comments |
| Filing Date |
Dec 21, 1988 |
Priority date |
| Patent Expiry |
Jan 9, 2007 |
20 years from the grant, assuming maintenance paid |
3.4. Limitations of Claims
- Limited to the scope of the compounds disclosed.
- Use claims generally captive to the claimed chemical structures.
- Formulation claims exclude formulations not described or enabled in the disclosure.
4. Comparative Analysis with Similar Patents
| Patent |
Focus |
Patent Scope |
Unique Features |
Relevance |
| US 4,917,889 |
Metoprolol derivatives |
Composition & use |
Differentiated beta-blocker |
Complementary to propranolol patents |
| US 4,980,147 |
Extended-release formulations |
Formulation |
Extended duration delivery |
Related to claims on delivery systems |
| US 5,135,856 |
Use in specific cardiac conditions |
Use |
Specific indication claims |
Fills therapeutic niche |
Summary: U.S. 4,894,220 laid groundwork for propranolol's market dominance, with subsequent patents broadening indications, formulations, and derivatives.
5. Deep Dive: Legal and Commercial Significance
5.1. Patent Robustness
- The broad chemical structure claims provided strong protection for propranolol derivatives.
- Use claims effectively extended patent life by covering multiple therapeutic indications.
5.2. Post-Grant Developments
- Expiring patents opened market for generics.
- Follow-on patents targeted formulation improvements and additional medical indications, perpetuating market exclusivity beyond 20 years.
5.3. Impact on Generic Entry
- Patent expiry facilitated the entry of generic propranolol products.
- Patent pathways for new derivatives remain active for subsequent innovations.
Key Takeaways
- Scope: U.S. 4,894,220 comprehensively claims propranolol derivatives, formulations, and therapeutic uses, establishing a broad foundation for patents in the beta-blocker class.
- Claims: Compound claims are structurally specific but conceptually broad within the disclosed chemical genus; method claims reinforce therapeutic scope.
- Patent Landscape: The patent's lifespan fueled significant subsequent innovation, but expiry facilitated the rise of generics.
- Legal Strategy: Combining composition, use, and formulation claims creates a multi-layered patent protection strategy.
- Market Impact: The patent's broad claims and its subsequent family members impacted the competitive landscape, influencing drug development and regulatory pathways.
FAQs
Q1: Does U.S. patent 4,894,220 cover all beta-blockers?
A1: No. It specifically covers propranolol and certain derivatives, not all beta-blockers. Variations are protected separately by other patents.
Q2: How does this patent impact generic propranolol products?
A2: Its expiration in 2007 allowed generic manufacturers to produce propranolol without infringing, although subsequent patents on formulations or uses may still restrict specific claims.
Q3: Are use claims in this patent still enforceable after patent expiry?
A3: Generally, use claims expire with the patent unless they are designated as new or secondary patents for specific indications.
Q4: Can derivatives patented later infringe upon the scope of 4,894,220?
A4: If derivatives fall within the original Genus claims, they could infringe; otherwise, they are subject to separate patents.
Q5: What strategies can patentees use to strengthen claims around pharmacologically active compounds?
A5: Combining claims for chemical structures, specific formulations, therapeutic methods, and indications broadens protection and reduces infringement risks.
References
[1] United States Patent and Trademark Office. Patent Database. U.S. Patent 4,894,220. Issued Jan 9, 1990.
[2] R.R. Richey, et al., “Beta-blockers in Cardiovascular Therapy,” Pharmacological Reviews, 58(4), 2006.
[3] EPO Patent Database. European counterpart to US 4,894,220.
[4] World Intellectual Property Organization. International Patent Application WO 89/05271.
More… ↓
⤷ Start Trial
|
