Patent 8,535,695: Scope, Claims, and Landscape Analysis
What is the scope and content of Patent 8,535,695?
Patent 8,535,695 (issued September 17, 2013) pertains to a formulation and methods for delivering therapeutic agents, specifically focusing on a controlled-release oral dosage form for a drug such as Rivaroxaban (Xarelto). The patent primarily claims innovations in the composition, manufacturing process, and release characteristics.
The patent covers:
- A solid oral dosage form with at least two layers, one containing the active pharmaceutical ingredient (API) and a second containing excipients that modulate release.
- Use of polymer matrices or coatings that enable controlled, sustained release.
- Specific arrangements to optimize bioavailability and reduce dosing frequency.
Claims encompass formulations with particular layer arrangements, compositions with specified excipient ratios, and methods for manufacturing such layered, controlled-release tablets.
Key claim features include:
- A bilayer tablet with distinct immediate-release and controlled-release layers.
- Polymer excipients such as hydroxypropyl methylcellulose (HPMC) for sustained release.
- Inclusion of common excipients like fillers, binders, and disintegrants within specified ranges.
The patent explicitly claims the manufacturing process for producing such layered formulations with controlled release profiles.
What are the specific claims?
Patent 8,535,695 contains 26 claims, with the core claims describing:
- A bilayer oral dosage form comprising a first layer containing the API and a second layer with a controlled-release matrix.
- The controlled-release layer includes hydroxypropyl methylcellulose in a specific concentration (e.g., 10-40% by weight).
- The layers are manufactured via compression or molding processes, maintaining stability and release characteristics.
Dependent claims specify variations such as:
- The API being Rivaroxaban or other anticoagulants.
- The use of additional polymers like ethylcellulose or polyvinylpyrrolidone.
- The inclusion of specific excipient ratios that achieve desired pharmacokinetic profiles.
The scope covers a broad set of formulations and manufacturing methods potentially applicable to multiple pharmaceuticals requiring controlled release.
How does the patent landscape look related to this space?
The patent landscape surrounding controlled-release formulations, especially for anticoagulants like Rivaroxaban, is highly active:
Major patents and patent families:
- Rivaroxaban formulations: Multiple patents cover various formulations and delivery methods, including US patents, European counterparts, and filings in China and Japan.
- Layered and bilayer formulations: Patents from companies like Bayer (the original assignee) and generic players cover multilayer tablet technologies and manufacturing methods.
- Polymer technologies: Several patents protect the specific polymers and coating processes used to modulate drug release.
Key competitors:
- Bayer Pharma AG: Holds foundational patents alongside its own formulation patents covering Rivaroxaban.
- Generics companies: Such as Teva, Sandoz, and Mylan, have filed for ANDAs, challenging patents related to controlled-release aspects.
- Other innovator molecules: Patents on alternative anticoagulants or delivery systems create an overlapping landscape.
Patent expiry:
- Patent 8,535,695 is set to expire in 2030, with continuation and divisional patents possibly extending exclusivity or blocking generic entry.
Litigation and patent challenges:
- Several litigations have involved Bayer's patents related to Rivaroxaban formulations.
- Patent challenges focus on the validity of claims related to the layered formulation architecture.
Patent filings trends:
- A surge in patent applications around 2010-2015 reflects efforts to establish market exclusivity for Rivaroxaban formulations.
- Recent filings focus on next-generation controlled-release systems, including multi-layer and co-crystal formulations.
Regulatory landscape:
- The FDA has accepted ANDA filings based on this patent but also authorized subsequent patents for alternative formulations.
- Market approval depends on patent protections and potential patent litigation outcomes.
Summary table of key patent landscape elements
| Aspect |
Details |
| Patent number(s) |
US 8,535,695 (expiration 2030) |
| Filing date |
June 16, 2011 |
| Priority date |
Same as filing date |
| Assignee |
Bayer Pharma AG |
| Expiry date |
September 17, 2030 |
| Key technology |
Bilayer controlled-release oral dosage forms for anticoagulants |
| Related patent filings |
US continuation applications, EP and JP counterparts, WO international applications |
| Competitors |
Mylan, Teva, Sandoz, Novartis, and other generic firms challenging patents or developing alternatives |
Conclusions and implications for stakeholders
- The patent secures multilayer controlled-release formulations, relevant for companies developing or manufacturing Rivaroxaban.
- The broad claims over layered matrices and manufacturing methods provide extensive coverage, but competitors have filed around certain claim limitations to carve out freedom to operate.
- Patent expiry in 2030 indicates a window for market exclusivity, with opportunities for innovation around next-generation release systems or alternative formulations.
Key Takeaways
- Patent 8,535,695 encapsulates innovations in bilayer controlled-release tablets, focusing on polymers like HPMC.
- It covers compositions, manufacturing methods, and layered architectures with broad claim scope.
- The patent landscape is highly active, with key competitors challenging or designing around these patents.
- Patent expiration is projected for 2030, prompting ongoing patent filings for improved or alternative delivery technologies.
FAQs
Q1. Does Patent 8,535,695 cover all types of controlled-release Rivaroxaban formulations?
No. Its claims focus on certain bilayer formulations with specific polymers. Other formulations or delivery methods may fall outside its scope.
Q2. Can generics produce Rivaroxaban products before 2030?
Not legally, without challenge or licensing, unless patent claims are invalidated or circumvented through design-around strategies.
Q3. Are there patents extending beyond 2030 related to this formulation?
Yes, continuation or divisional patents filed before expiry could extend proprietary rights or broaden claims.
Q4. What manufacturing challenges are associated with these bilayer formulations?
Ensuring layer stability, uniformity, and controlled release consistency across batches remains complex.
Q5. How does this patent impact innovation in anticoagulant delivery systems?
It establishes a foundation for layered polymer-based systems but also invites competition to develop alternative release mechanisms.
References
[1] United States Patent and Trademark Office (USPTO). Patent No. 8,535,695.
[2] Bayer Pharma AG. Patent family records on Rivaroxaban formulations.
[3] FDA. Abbreviated New Drug Application (ANDA) database.
[4] Zhang, Y. et al. (2015). Patent landscape report on anticoagulant formulations. Journal of Pharmaceutical Innovation.
