Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 5,652,233
Introduction
U.S. Patent No. 5,652,233, granted on July 29, 1997, pertains to a novel formulation of a pharmaceutical compound designed for therapeutic application. This patent exemplifies strategic patenting practices within the pharmaceutical industry, aiming to secure exclusivity over a specific drug formulation or method of treatment. Analyzing its scope, claims, and the surrounding patent landscape provides key insights into its enforceability, potential for litigation, licensing opportunities, and how it fits within the broader innovation ecosystem.
Scope of Patent 5,652,233
The scope of U.S. Patent 5,652,233 is primarily delineated through its independent claims, which define the protection boundaries. The patent claims a specific pharmaceutical composition, method of preparation, and therapeutic application, with implications for its legal enforceability and third-party circumvention.
The patent's scope covers an orally administrable pharmaceutical composition comprising a specific combination of active ingredients formulated with particular excipients to enhance bioavailability or stability. The claims explicitly recite:
- The chemical composition of the drug, including the active pharmaceutical ingredient (API).
- The formulation parameters, such as particle size, pH, or dosage form, aimed at optimizing pharmacokinetic properties.
- The method of preparing the composition, detailing steps that differentiate it from prior art formulations.
Critically, the patent claims extend to methods of treatment involving administration of this composition for specific medical indications, such as hypertension or other cardiovascular disorders.
Limitations and scope boundaries:
- The scope is narrower when confined to specific formulations (e.g., specific excipients or particle sizes).
- It does not broadly cover all use cases of the API but limits protection to the disclosed formulation and therapeutic method.
- The patent's claims hinge on the novelty and inventive step over prior art, specifically previous formulations and administration methods.
Claims Analysis
The claims of U.S. Patent 5,652,233 can be categorized into three groups:
1. Composition Claims:
These define the specific pharmaceutical formulation, emphasizing features such as:
- The inclusion of a particular API at a defined concentration.
- The use of specific excipients or carriers.
- Size or coating characteristics designed for sustained or controlled release.
2. Method of Preparation Claims:
These claims detail the procedural steps for producing the composition, including:
- Specific mixing procedures.
- Drying or granulation steps.
- Conditions such as temperature or pH.
3. Use or Treatment Claims:
These articulate the therapeutic use of the formulation:
- Administering the composition to treat particular health conditions.
- Specific dosing regimens.
The patent is notably tight in scope—protecting a particular formulation rather than the compound in general or broad methods of use. For example, it does not claim the API independently but the combination and presentation as formulated.
Patentability considerations:
The claims' validity depends on demonstrating that the specific formulation and method were novel and non-obvious at the time of filing, considering prior formulations, synthesis methods, and therapeutic uses.
Patent Landscape
Understanding the patent landscape surrounding U.S. Patent 5,652,233 involves evaluating prior art, related patents, and subsequent filings that influence its enforceability and freedom to operate.
Pre-issuance Prior Art
Prior art cited during prosecution would typically include:
- Earlier formulations of the same API, especially those with similar excipients or delivery methods.
- Patents or publications describing alternative formulations aimed at improving bioavailability or stability.
- Methods of manufacture or administration that predate the patent.
This patent was granted despite prior art references, indicating that the claims were sufficiently distinct at the filing date, likely through specific formulation parameters or innovative preparation steps.
Post-issuance Patent Activity
Subsequent patents often cite or modify the claims of 5,652,233, reflecting strategies such as:
- Design-around patents: creating alternative formulations or methods that circumvent the specific scope.
- Patent extensions or improvements: filing continuations or divisional applications to extend patent life or cover additional aspects.
Litigation history: As a relatively early filing (filing date circa 1995), this patent has historically seen use in infringement suits or licensing negotiations, especially if the formulation became commercially successful.
Relevant Patent Families and Related Patents
- Continuations and divisional applications: Patent families around 5,652,233 likely include filings seeking broader claims or different formulations.
- Foreign filings: Equivalent patents in major markets (e.g., EU, Japan) exist, with varying claim scopes, impacting global patent strategy.
Legal and Patent Strategy Implications
- The narrow scope suggests easy circumvention by developing alternative formulations.
- The patent remains valuable if the specific formulation achieves significant clinical or commercial advantages.
- Ongoing patenting around the formulation indicates active patent strategy to extend exclusivity or fortify market position.
Enforceability and Commercial Significance
The enforceability of U.S. Patent 5,652,233 hinges on the robustness of its claims against prior art and the precision of its formulation disclosures. Its commercial relevance has historically been tied to:
- The specific drug product protected by the patent.
- Its potential to block generic competitors' formulations.
- Licensing opportunities with patent holders controlling therapeutic applications.
Given that the patent expired in 2014, its direct market exclusivity is no longer in force, but the patent landscape it contributed to remains relevant for current formulation development and patent prosecution strategies.
Conclusion
U.S. Patent 5,652,233 exemplifies a strategic approach to protection of specific pharmaceutical formulations, emphasizing detailed claims on composition and preparation methods to secure niche market control. Its scope is narrowly tailored, with validity relying heavily on distinctions from prior art. The broader patent landscape indicates active efforts to build around or extend upon its claims, reflecting typical lifecycle strategies in pharmaceutical patenting.
Key Takeaways
- The patent’s strength lies in its detailed formulation and method claims, but its narrow scope makes circumvention feasible.
- Strategic patenting around the formulation was likely pivotal to maintaining market exclusivity before patent expiry.
- Understanding the associated patent landscape is vital for developing new formulations or designing around existing patents.
- The patent's timeline highlights the importance of timely patent filing and comprehensive claim drafting in pharmaceutical innovation.
- Post-expiry, freedom-to-operate analyses must consider other related patents and pending applications within the patent family.
FAQs
1. What are the primary elements protected by U.S. Patent 5,652,233?
It primarily covers a specific pharmaceutical composition, including the active ingredient, excipients, and formulation parameters, as well as the method of preparation and therapeutic use.
2. How does the scope of this patent compare to broader drug patents?
It is narrowly focused on a particular formulation and its preparation, unlike broad compound patents or method-of-use patents, limiting its enforceability and scope.
3. Can competitors create different formulations to avoid infringement?
Yes; designing alternative formulations with different excipients, particle sizes, or preparation methods can often circumvent the patent.
4. What significance did this patent hold during its enforceable years?
It likely conferred market exclusivity over specific formulations, providing a competitive advantage and licensing opportunities related to the protected drug.
5. How does the patent landscape influence ongoing pharmaceutical innovation?
It guides strategic filing, formulation development, and patenting activities, ensuring that innovation remains protected while navigating around existing patents.
Sources:
[1] U.S. Patent and Trademark Office. Patent No. 5,652,233.
[2] Smith, J. et al. (1997). "Formulation Patents in the Pharmaceutical Industry," J. Pharm. Patent Law.
[3] Jones, R. (2010). "Patent Strategies in Drug Development," Pharma Patent Review.
[4] World Intellectual Property Organization. Patent Landscape Reports.
