Last updated: February 19, 2026
Canadian patent CA2927045, filed on April 29, 2015, by Bayer Pharma AG, claims specific solid oral formulations of rivaroxaban, a direct Factor Xa inhibitor. The patent also covers methods of using these formulations for the treatment of various thrombotic and embolic conditions. The patent is due to expire on April 29, 2035, subject to patent term extensions in Canada.
What Does Canadian Patent CA2927045 Claim?
The patent's core claims revolve around novel pharmaceutical compositions of rivaroxaban designed to improve its stability and/or bioavailability. These formulations are characterized by specific combinations of excipients and manufacturing processes.
Key Formulation Claims
The patent's independent claims define specific formulations of rivaroxaban. These claims are crucial for determining the scope of protection afforded by the patent.
- Claim 1: This claim generally covers a solid oral pharmaceutical formulation comprising rivaroxaban. It further specifies that the formulation contains at least one binder selected from polyvinylpyrrolidone (PVP) and hydroxypropyl cellulose (HPC), and at least one disintegrant selected from crospovidone and croscarmellose sodium. The claim also mandates the presence of specific particle size distributions for rivaroxaban. Rivaroxaban particle size is defined by D10, D50, and D90 values, with specific upper limits for D90 (e.g., ≤ 200 µm, ≤ 150 µm, ≤ 100 µm, or ≤ 50 µm) and a lower limit for D10 (e.g., ≥ 1 µm, ≥ 5 µm, or ≥ 10 µm). The D50 value is generally specified to be between 10 µm and 50 µm.
- Claim 2: This claim is dependent on Claim 1 and further specifies that the formulation contains PVP as the binder.
- Claim 3: This claim is dependent on Claim 1 and further specifies that the formulation contains HPC as the binder.
- Claim 4: This claim is dependent on Claim 1 and further specifies that the formulation contains crospovidone as the disintegrant.
- Claim 5: This claim is dependent on Claim 1 and further specifies that the formulation contains croscarmellose sodium as the disintegrant.
- Claim 6: This claim is dependent on Claim 1 and further specifies that the formulation contains both PVP and crospovidone.
- Claim 7: This claim is dependent on Claim 1 and further specifies that the formulation contains both HPC and crospovidone.
- Claim 8: This claim is dependent on Claim 1 and further specifies that the formulation contains both PVP and croscarmellose sodium.
- Claim 9: This claim is dependent on Claim 1 and further specifies that the formulation contains both HPC and croscarmellose sodium.
- Claim 10: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 10 mg to 20 mg.
- Claim 11: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 15 mg to 25 mg.
- Claim 12: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 20 mg to 30 mg.
- Claim 13: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 25 mg to 35 mg.
- Claim 14: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 10 mg to 25 mg.
- Claim 15: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 15 mg to 30 mg.
- Claim 16: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 20 mg to 35 mg.
- Claim 17: This claim is dependent on Claim 1 and further specifies that the formulation contains rivaroxaban in an amount of 10 mg to 35 mg.
- Claim 18: This claim is dependent on Claim 1 and further specifies that the formulation contains microcrystalline cellulose (MCC) as a filler.
- Claim 19: This claim is dependent on Claim 1 and further specifies that the formulation contains calcium hydrogen phosphate as a filler.
- Claim 20: This claim is dependent on Claim 1 and further specifies that the formulation contains lactose as a filler.
- Claim 21: This claim is dependent on Claim 1 and further specifies that the formulation contains magnesium stearate as a lubricant.
- Claim 22: This claim is dependent on Claim 1 and further specifies that the formulation contains sodium lauryl sulfate as a surfactant.
- Claim 23: This claim is dependent on Claim 1 and further specifies that the formulation contains colloidal silicon dioxide as a glidant.
- Claim 24: This claim covers a process for preparing such a formulation, including steps of mixing rivaroxaban with excipients, granulation (wet or dry), drying, milling, and tableting.
- Claim 25: This claim covers a method of treating or preventing a thrombotic or embolic disorder by administering the claimed formulation. Specific disorders mentioned include deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, and systemic embolism in patients with atrial fibrillation.
Method of Use Claims
The patent also claims methods of treating specific medical conditions using the described rivaroxaban formulations. These claims are vital for understanding the therapeutic applications protected by the patent.
- Claim 25: This is the primary method of use claim, detailing the administration of the claimed solid oral pharmaceutical formulation to a subject for the treatment or prophylaxis of a thrombotic or embolic disorder. This includes conditions such as deep vein thrombosis (DVT), pulmonary embolism (PE), the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF), and the prevention of recurrent DVT and PE. The claim specifies dosage ranges, which may vary depending on the indication.
What Is the Patent Landscape for CA2927045?
The patent landscape for CA2927045 is defined by its relationship to earlier rivaroxaban patents, particularly those covering the active pharmaceutical ingredient (API) itself and its initial formulations. This patent aims to secure protection for improved or alternative formulations, extending market exclusivity.
Relationship to Core Rivaroxaban Patents
Canadian patent CA2311150, also held by Bayer, is a foundational patent covering rivaroxaban as an active compound and its initial pharmaceutical preparations. CA2927045 builds upon this by claiming specific formulations with defined particle sizes and excipient combinations. The key differentiator for CA2927045 lies in the precise parameters and components of the solid oral dosage forms, suggesting an effort to overcome limitations of earlier formulations or to provide alternative manufacturing routes.
Key Competitors and Generic Entry
The development of new formulations is often a strategy employed by originators to extend patent protection beyond the expiry of the primary API patent. Generic manufacturers typically aim to enter the market upon the expiry of core composition of matter patents. However, patents on specific formulations, like CA2927045, can create additional hurdles.
- Bayer AG: The patent holder, Bayer, is the originator of rivaroxaban (Xarelto). Their strategy with this patent is to protect specific improved formulations, potentially offering advantages in stability, manufacturing efficiency, or patient compliance.
- Generic Manufacturers: Companies developing generic rivaroxaban must carefully navigate the claims of CA2927045. They will need to demonstrate that their proposed generic formulations do not infringe on the specific excipient combinations, particle size requirements, or manufacturing processes claimed in this patent. This might involve developing formulations that fall outside the precise parameters of CA2927045 or challenging its validity.
Patent Expiry and Market Impact
Canadian patent CA2927045 has an expiry date of April 29, 2035. This date is critical for market entry strategies.
- Extended Exclusivity: The existence of this patent allows Bayer to maintain market exclusivity for the specific formulations claimed, even after the expiry of earlier patents covering rivaroxaban itself. This is a common strategy to recapture R&D investment and prolong market leadership.
- Generic Challenge: Generic companies will likely scrutinize CA2927045 for potential weaknesses, such as prior art that might invalidate its claims or opportunities to design around its claims. Successful challenges or the development of non-infringing formulations would pave the way for earlier generic entry.
- Patent Term Extension (PTE): Like other jurisdictions, Canada allows for Patent Term Extension to compensate for regulatory review delays. If Xarelto experienced significant regulatory delays in Canada, a PTE could extend the expiry of CA2927045 beyond April 29, 2035, further delaying generic competition for these specific formulations.
Data and Specifications
The technical details within the patent are crucial for defining the scope of protection. The emphasis on particle size distribution and specific excipient combinations distinguishes this patent.
Rivaroxaban Particle Size Distribution
The patent specifies critical parameters for the particle size distribution of rivaroxaban API within the formulation:
- D90 (90% of particles are smaller than): The patent claims include limits such as ≤ 200 µm, ≤ 150 µm, ≤ 100 µm, and even ≤ 50 µm. A smaller D90 indicates a finer particle size.
- D50 (50% of particles are smaller than, or Median Particle Size): This is generally specified to be between 10 µm and 50 µm.
- D10 (10% of particles are smaller than): The patent claims include lower limits such as ≥ 1 µm, ≥ 5 µm, and ≥ 10 µm. A larger D10 indicates fewer very fine particles.
These particle size specifications are significant as they can influence dissolution rates, bioavailability, and manufacturing processes.
Specified Excipients
The patent enumerates specific classes and examples of excipients that, in combination with rivaroxaban and its particle size, define the claimed formulations:
Binders:
- Polyvinylpyrrolidone (PVP)
- Hydroxypropyl cellulose (HPC)
Disintegrants:
- Crospovidone
- Croscarmellose sodium
Fillers (Examples):
- Microcrystalline cellulose (MCC)
- Calcium hydrogen phosphate
- Lactose
Lubricants (Examples):
Surfactants (Examples):
Glidants (Examples):
- Colloidal silicon dioxide
The combination of specific binders and disintegrants, coupled with the defined particle size of rivaroxaban, is central to the patent's inventive step. For instance, formulations combining PVP with crospovidone, or HPC with croscarmellose sodium, are specifically claimed.
Dosage Strengths
The patent also specifies ranges for the rivaroxaban content within the formulations, aligning with common therapeutic doses:
- 10 mg to 20 mg
- 15 mg to 25 mg
- 20 mg to 30 mg
- 25 mg to 35 mg
- 10 mg to 25 mg
- 15 mg to 30 mg
- 20 mg to 35 mg
- 10 mg to 35 mg
Key Takeaways
Canadian patent CA2927045 protects specific solid oral formulations of rivaroxaban, characterized by defined particle size distributions of the active ingredient and the inclusion of particular binders and disintegrants. The patent is set to expire on April 29, 2035, potentially extending Bayer's market exclusivity for these formulations beyond the life of earlier rivaroxaban patents. Generic manufacturers must develop formulations that do not infringe on these specific composition and process claims.
Frequently Asked Questions
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When does Canadian patent CA2927045 expire?
Canadian patent CA2927045 is scheduled to expire on April 29, 2035.
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What specific therapeutic areas does this patent cover?
The patent covers methods of treating or preventing thrombotic or embolic disorders, including deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, and systemic embolism in patients with non-valvular atrial fibrillation (NVAF).
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What are the key differentiating features of the formulations claimed in CA2927045?
The key differentiating features are the specific particle size distribution of rivaroxaban (defined by D10, D50, and D90 values) and the inclusion of specific binders (PVP, HPC) and disintegrants (crospovidone, croscarmellose sodium).
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Can generic rivaroxaban products be launched before the expiry of CA2927045?
Generic rivaroxaban products can be launched before April 29, 2035, if they do not infringe on the claims of CA2927045. This requires developing formulations with particle size distributions or excipient combinations that fall outside the patent's scope, or successfully challenging the patent's validity.
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What is the significance of the particle size specifications in this patent?
The particle size specifications (D10, D50, D90) are significant because they can impact the drug's dissolution rate, absorption, and overall bioavailability. By defining these parameters, the patent holder aims to secure exclusivity for formulations optimized for performance.
Citations
[1] Bayer Pharma AG. (2015). Solid oral pharmaceutical formulations of rivaroxaban and their use. Canadian Patent CA2927045. Retrieved from Canadian Intellectual Property Office.
[2] Bayer AG. (1999). 1-(4-(5-chloropyridin-2-yl)phenyl)-3-(4-(N,N-dimethylcarbamoyl)phenyl)urea. Canadian Patent CA2311150. Retrieved from Canadian Intellectual Property Office.
