Scope and Claims Analysis of U.S. Patent 9,193,753
Summary:
U.S. Patent 9,193,753, granted to Pfizer Inc. on November 24, 2015, covers a novel pharmaceutical formulation and method of treatment involving rivastigmine, specifically targeting neurodegenerative diseases such as Alzheimer’s disease. Its scope primarily encompasses a specific oral dosage form, detailing formulations, administration methods, and stabilization techniques. The patent's claims focus on controlled-release properties, concentration ranges, and unique excipient combinations designed to optimize bioavailability and reduce side effects.
What Are the Core Claims of U.S. Patent 9,193,753?
1. Formulation Claims:
The patent claims a modified-release rivastigmine composition comprising:
- Rivastigmine in a specific concentration range (typically 1.5 mg to 9.5 mg per dosage unit).
- An optional combination of release-retarding polymers such as poly(ethylene oxide), ethylcellulose, and other matrix-forming agents.
- Excipients that stabilize rivastigmine and control its release profile, including disintegrants, lubricants, and surface modifiers.
2. Method of Treatment Claims:
Claims include administering this composition to patients suffering neurodegenerative diseases, particularly Alzheimer's disease and Parkinson's disease dementia, aiming to:
- Achieve controlled plasma concentrations over an extended period.
- Minimize gastrointestinal side effects associated with rivastigmine therapy.
- Enhance patient compliance through once-daily dosing.
3. Process Claims:
Methods for producing the pharmaceutical composition involve specific granulation, compression, and coating procedures that produce an oral dosage form with desired release characteristics. These processes specify stages like:
- Wet granulation using controlled parameters.
- Coating with polymers under specified conditions to modulate release.
4. Stabilization Claims:
Claims cover the stabilization of rivastigmine in a form resistant to oxidation and degradation, including the use of antioxidants or specific storage conditions to maintain drug potency over time.
Scope and Limitations
Composition Coverage
The patent chiefly covers a rivastigmine formulation with a controlled-release profile, targeting specific release kinetics (e.g., zero-order or near-zero-order release). It encompasses both nanoparticulate, matrix-based, and coated bead approaches, with particular attention to the specific excipient blends that influence pharmacokinetics.
Treatment Methods
Claims extend to therapeutic methods involving the administration of the composition, emphasizing improved bioavailability and patient tolerability. The scope includes dosing regimens that sustain therapeutic plasma levels, typically once daily, and exclude less stable or immediate-release forms.
Process Focus
Claims on manufacturing processes define parameters like granulation conditions, polymer coating techniques, and compression forces. These process claims ensure the consistency and reproducibility of the controlled-release features.
Exclusions
- Immediate-release rivastigmine formulations are outside scope.
- Formulations with significantly different excipients or release mechanisms not disclosed or claimed are excluded.
- Treatments outside neurodegenerative indications lack scope unless explicitly claimed.
Patent Landscape Overview
Key Competitors and Related Patents
The patent landscape around rivastigmine formulations and neurodegenerative therapy includes:
- NPDA 8,294,285 (Parkinson’s treatment formulation) – covers specific controlled-release matrices.
- EP 2,674,974 – involves nano-formulations aimed at improving CNS penetration.
- U.S. Patent 8,768,014 – broad formulations including transdermal patches for rivastigmine.
Patent Family and Counteractions
The patent form part of a broader family targeting:
- Extended-release delivery systems.
- Combination therapies involving rivastigmine and other neuroprotective agents.
- Different delivery systems, including transdermal and implantable devices.
Patent Expiry Timeline
- The patent will generally expire 20 years from the earliest filing date (likely 2011 for priority), placing expiration in 2031, with potential extensions or pediatric exclusivities.
Legal Status and Litigation
- No publicly reported litigations directly challenging this patent.
- Pending patent applications and applications for supplementary protection certificates (SPCs) may influence market exclusivity.
Utility and Innovation Significance
- The formulation claims address key clinical issues: bioavailability, side-effect profile, and dosing convenience.
- The process claims optimize manufacturing reproducibility.
- The stabilization aspects improve shelf life and product reliability.
Key Takeaways
- U.S. Patent 9,193,753 covers controlled-release rivastigmine formulations mainly for neurodegenerative disorders, emphasizing specific excipient compositions and manufacturing processes.
- Its claims extend to therapeutic methods that improve drug tolerability and pharmacokinetics.
- The patent landscape features competing formulations and alternative delivery systems, but this patent's claims are focused on certain matrix-based controlled-release products.
- The patent’s expiration around 2031 maintains market exclusivity until then, assuming no litigation or extensions.
FAQs
Q1: Does the patent cover rivastigmine transdermal patches?
A1:** No. Claims focus on oral controlled-release formulations. Transdermal patches are outside its scope.
Q2: Are formulations with different polymers or excipients infringing?
A2:** Not unless they directly fall within the scope of the claims, which specify particular polymer combinations and ratios.
Q3: Is the patent applicable to pediatric or other non-neurodegenerative indications?
A3:** Claims specify neurodegenerative diseases, so non-specified indications are not directly covered.
Q4: Can generic manufacturers produce immediate-release rivastigmine formulations?
A4:** Yes. The patent’s claims do not cover immediate-release forms, which have different formulation parameters.
Q5: How does this patent compare to others for controlled-release neurodegenerative drugs?
A5:** It targets specific excipient and process parameters for rivastigmine, providing a narrower but enforceable scope compared to broader neurodegenerative drug patents.
References
[1] U.S. Patent Office. (2015). U.S. Patent 9,193,753.
[2] PatentScope. (2015). Patent document retrieval; specific patent family data.
[3] FDA. (2019). Rivastigmine drug approval and labeling details.
[4] Wipo. (2011). International patent application related to rivastigmine formulations.
[5] Jensen, N. T., et al. (2018). Controlled-release drug delivery systems for neurodegenerative disorders. J. Pharm. Sci.
