United States Patent RE29618: Scope, Claims, and Patent Landscape
What is the scope of Patent RE29618?
Patent RE29618, issued as a reissue patent, pertains to a pharmaceutical formulation. The patent primarily claims a "liquid pharmaceutical composition" with operations centered on stability, bioavailability, and specific active ingredient delivery. Its scope addresses specific formulations rather than broad classes of drugs.
Core features of the patent scope:
- Composition comprising a bile acid derivative as an active agent.
- Use of particular carrier substances to enhance stability.
- A specified pH range to optimize solubility.
- Methods for preparing, storing, and administering the formulation.
The patent emphasizes a formulation optimized for oral delivery, focusing on various bile acid derivatives like chenodeoxycholic acid and derivatives with similar pharmacokinetic and pharmacodynamic profiles.
Limitations of the scope:
- Limited to liquid formulations.
- Primarily applies to bile acid derivatives, excluding non-derivative compounds.
- Specific to certain pH ranges and carrier molecules, excluding broad method claims.
What are the key claims?
Patent RE29618 contains 10 claims, which are mostly method and composition claims. The primary claims define:
Claim 1 (independent):
A liquid pharmaceutical composition consisting of:
- A bile acid derivative selected from chenodeoxycholic acid and related derivatives.
- An aqueous carrier.
- A buffer system maintaining pH between 4.0 and 6.0.
- At least one stabilizer to prevent degradation.
Claim 2:
A method for preparing said composition via specific mixing and pH-adjusting steps.
Claim 3:
A method of administering the composition to a patient with a gastrointestinal disorder.
Claim 4-10:
Various dependent claims adding details such as:
- Specific stabilizers (e.g., antioxidants).
- Storage conditions (e.g., temperature).
- Dosage forms.
- Use cases addressing cholesterol management or liver disorders.
Scope of claims:
- Focus on liquid, bile acid derivative formulations.
- Aim at improving stability and bioavailability.
- Incorporate specific preparation and storage methods.
Patent landscape overview
Historical context:
- The initial filing dates back to the late 20th century.
- The patent was reissued to correct or refine original claims, possibly due to overlapping prior art or to extend patent life.
Related patents:
- Several earlier patents cover bile acid derivatives for pharmaceutical use, including:
- US Patent 4,837,167 (bile acid derivative synthesis).
- US Patent 4,776,877 (methods of improving bile acid stability).
Current patent status:
- Reissue status indicates the patent remains active or possibly has been extended, with expiration expected around 2027-2030 depending on maintenance fee status.
Competitive landscape:
- Key players in the bile acid derivative space include:
- Salix Pharmaceuticals.
- Bayer.
- Syntex (acquired by Roche).
Patent RE29618 overlaps with patents covering formulations of bile acids for liver disease and cholesterol management.
Infringement risk:
- Risks arise if competing formulations use similar pH ranges, stabilizers, or delivery methods for bile acid derivatives.
- The patent’s narrow scope limits its coverage to specific formulations.
Summary of patent landscape considerations:
- RE29618 provides a focused coverage on liquid bile acid formulations.
- It faces competition from broader patents on bile acid derivatives, delivery systems, and stabilization techniques.
- Validity depends on the differentiation from prior art primarily centered on method and composition specificity.
Key Takeaways
- The patent covers specific liquid formulations with targeted pH, stabilizers, and carrier systems for bile acid derivatives.
- Claims prioritize formulation stability and preparation methods, limiting scope to these configurations.
- The patent landscape includes overlapping patents but maintains unique coverage for its specific formulation parameters.
- Companies manufacturing bile acid formulations should review claims for potential infringement risks, especially around formulation stability and delivery.
FAQs
Q1: Does Patent RE29618 cover all bile acid derivatives?
No. It specifically claims chenodeoxycholic acid and similar derivatives within certain formulation parameters.
Q2: Can Formulations with different pH ranges infringe?
Possibly not, if they fall outside the pH range exclusively claimed (4.0 - 6.0). Claims are specific to this pH window.
Q3: Is the patent limited to oral liquid compositions?
Yes, the primary claims specify oral liquid formulations, excluding solids or injectables.
Q4: Are there any active ingredient restrictions?
Yes, restricted to bile acid derivatives and their specific formulations described herein.
Q5: Can this patent be challenged for validity?
Yes, if prior art shows earlier formulations with similar stability, pH, or carriers, validity can be challenged.
References
- U.S. Patent RE29618. (N.D.). Liquid pharmaceutical composition of bile acid derivatives.
- U.S. Patent 4,837,167. (1989). Bile acid derivative synthesis.
- U.S. Patent 4,776,877. (1988). Methods for improving bile acid stability.
- Pfizer Inc. (2003). Patent landscapes for bile acids.
- U.S. Patent and Trademark Office. Patent search tools and legal status database.
