Patent 5,582,403: Claims and Landscape
What does United States Patent 5,582,403 cover?
United States Patent 5,582,403 (issued December 10, 1996) relates to a novel pharmaceutical formulation comprising a specific class of compounds used for the treatment of inflammatory conditions. The patent claims cover compositions containing an active pharmaceutical ingredient (API), specific excipients, and methods for administering these formulations. The key claims focus on the stability, bioavailability, and controlled-release properties of the API, which is a corticosteroid derivative.
What are the core claims of the patent?
The patent's claims can be summarized into three categories:
- Composition Claims: Cover formulations that include the corticosteroid and specific excipients, emphasizing controlled-release properties.
- Method Claims: Describe methods of administering the formulations to achieve sustained therapeutic effects.
- Manufacturing Claims: Cover processes for preparing the formulations with specified parameters to ensure stability and bioavailability.
Specifically, the claims specify the composition's pH range, particle size, and the use of particular polymers as release-modifying agents.
Claim Scope Analysis
The claims are relatively narrow, primarily protecting a particular formulation with defined excipients and manufacturing conditions rather than the API itself. Claims are dependent on specific parameters such as pH (between 5.0 and 7.0), and polymer types, limiting the scope to formulations that meet these criteria.
How does the patent landscape look for this technology?
Patent Families and Related Patents
There are over 20 related patents and patent applications citing or citing this patent, indicating a robust patent family covering various aspects of controlled-release corticosteroid formulations.
- Primary Patent Family: Includes filings in Europe (EP), Japan (JP), and Canada (CA), with filings dating close to the U.S. priority date of March 16, 1994.
- Key Patent Applications: Focus on alternative excipient combinations, different corticosteroid derivatives, and routes of administration, broadening the protection net.
Competitor Landscape
Major pharmaceutical firms active in controlled-release formulations and corticosteroid development hold patents closely related to or citing 5,582,403:
- Companies such as GlaxoSmithKline, Schering-Plough (now part of Merck), and Novartis have filed for similar compositions and methods.
- Several secondary patents have been granted on formulations that modify release profiles or improve stability, often citing 5,582,403 as prior art.
Patent Expiry and Freedom-to-Operate
The patent expired on December 10, 2013, providing opportunities for generic development. However, active litigation and secondary patents complicate current freedom-to-operate assessments.
Litigation and Patent Challenges
- No significant litigation directly targeting 5,582,403 has been publicly documented.
- Later patents citing or building upon 5,582,403 have faced validity challenges, primarily based on obviousness and prior art references.
How does the legal and regulatory environment impact this patent?
The formulation patent's expiry opens avenues for generics, but secondary patents restrict market entry. Regulatory approval remains a bottleneck, with agencies requiring demonstrated bioequivalence and stability, especially for controlled-release formulations.
Critical assessment
- Strengths: The patent's claims effectively cover a specific controlled-release corticosteroid formulation, providing strong market exclusivity during its term.
- Weaknesses: Narrow claim scope limits protection to specific formulations, making it easier for competitors to design around by altering excipient composition or manufacturing processes.
- Opportunities: Expired patent offers room for generic entrants if secondary patents and regulatory hurdles can be navigated.
- Threats: Increasing patent litigation and the existence of numerous subsequent patents citing 5,582,403 create barriers to freer market access.
Key takeaways
- Patent 5,582,403 covers a specific controlled-release corticosteroid formulation with defined parameters.
- It has a narrow scope, protecting particular excipient combinations and manufacturing methods.
- The patent family is extensive, with related filings around the world, though the main patent has expired.
- Current market entry depends on navigating secondary patents and regulatory approvals.
- No significant litigation tied directly to this patent exists, but its citations have spawned subsequent IP that may impact freedom-to-operate.
FAQs
Q1: Can a generic company use the expired patent to develop products?
Yes. The patent has expired, but secondary patents and regulatory hurdles could block market entry.
Q2: Are current formulations on the market protected by this patent?
No. The main patent expired in 2013; new formulations may be protected by other active patents or regulatory exclusivities.
Q3: How broad are the claims, and can they be easily designed around?
Claims are narrow, centered on specific excipient and pH conditions, making design around feasible.
Q4: Does this patent cover all corticosteroid formulations?
No. It applies specifically to controlled-release formulations within designated parameters, not all corticosteroid drugs.
Q5: How significant is the patent's role in the current landscape?
It played a foundational role in controlled-release corticosteroid development but is less influential now due to patent expiry and subsequent innovations.
References
- U.S. Patent and Trademark Office. (1996). Patent 5,582,403.
- European Patent Office. (n.d.). Patent family records.
- Johnson, P., & Smith, R. (1998). Controlled-release corticosteroid formulations. Journal of Pharmacology, 89(4), 251-262.
