Last updated: March 2, 2026
What Is the Scope of Patent CN102712584?
Patent CN102712584, filed on September 19, 2012, by Jiangsu Hengrui Medicine Co., Ltd., is titled "Polymorphic forms of a Compound and Uses thereof." It primarily covers specific crystalline forms of the compound known as "rosuvastatin calcium" and their pharmaceutical applications.
The patent claims comprise protection of at least two polymorphs:
- Form A: A crystalline form with a specific XRPD (X-ray powder diffraction) pattern, labeled as Form A.
- Form B: An alternative crystalline form with a distinctive XRPD pattern, labeled as Form B.
The patent also claims methods for preparing these polymorphs and their use in treating hyperlipidemia. The scope explicitly covers methods of producing these forms, pharmaceutical compositions containing them, and their therapeutic uses.
The claims are structured as follows:
- Claims 1–4: Cover the crystalline forms (Forms A and B) of rosuvastatin calcium, characterised by their XRPD patterns.
- Claims 5–7: Cover processes for preparing the crystalline forms.
- Claims 8–10: Cover pharmaceutical compositions containing these crystalline forms.
- Claims 11–13: Cover therapeutic uses in hyperlipidemic conditions.
The patent’s claims are specific to the crystalline forms, providing protection against others producing identical polymorphs with similar XRPD patterns. The detailed XRPD data significantly narrow the scope but are typical for polymorph patents.
How Do the Claims Define the Patent’s Legal Boundaries?
The claims focus on crystalline polymorphs defined by their XRPD patterns, melting points, and other physical properties, which limits the scope to particular crystal habits. This prevents generic replication of the specific polymorphs but allows for the development of alternative polymorphs or methods that avoid infringement through different crystalline forms.
The patent does not claim the compound rosuvastatin calcium itself in broad terms but restricts protection to the specific polymorphs characterised by their XRPD profiles, which are:
- Form A: XRPD peaks at specific 2θ values (e.g., 13.4°, 19.7°, etc.) with detailed intensity data.
- Form B: Different XRPD pattern with peaks at unique 2θ values (e.g., 14.9°, 21.2°, etc.).
Claims extending to methods of preparation and pharmaceutical compositions increase the patent's enforceability across the supply chain of formulations using these polymorphs.
What Is the Patent Landscape for Rosuvastatin Polymorphs in China?
Existing Patents
In China, several patents cover rosuvastatin, including methods for synthesis, formulations, and crystalline forms:
| Patent Number |
Title |
Focus |
Filing Year |
Status |
| CN102007459 |
Crystalline Form of Rosuvastatin Calcium |
Crystalline polymorphs |
2010 |
Granted |
| CN102712584 |
Polymorphic Forms of Rosuvastatin Calcium |
Specific XRPD-defined polymorphs |
2012 |
Granted |
| CN105586359 |
Process for Preparing Rosuvastatin Salt |
Synthesis and process |
2015 |
Granted |
These patents collectively cover the core crystalline and process innovations around rosuvastatin.
Key Related Patents
- CN102007459 claims a crystalline form with XRPD peaks at different specific angles, potentially overlapping but broad enough to include other polymorphs.
- CN105586359 describes a process for preparing rosuvastatin calcium, broad enough to include multiple polymorphs produced via different methods.
Patent Families and Competition
The patent landscape is fragmented with overlapping claims:
- Multiple patents claim polymorphs based on XRPD patterns, often with narrow scope.
- Several patents focus on synthesis and process innovations, potentially overlapping or complementing the polymorph patents.
Legal disputes in China have centered around the scope of claims for crystalline forms, especially in how broadly they can cover alternative polymorphs with similar physical properties.
Patent Challenges and Freedom to Operate
Filing strategies in China include:
- Narrow polymorph claims (e.g., CN102712584) limiting infringement risks.
- Broad process patents that may cover multiple polymorphs.
Patent invalidation or opposition has focused on claims that are excessively narrow or specific, especially for polymorphs with similar XRPD profiles.
Implications for R&D and Commercialization
- Claim scope restricts others from manufacturing or selling identical polymorphs but allows for development of alternative crystalline forms.
- Process patents offer defensive IP but are easier to design around.
- Use patents for specific indications, like hyperlipidemia treatment, extend protection.
Key Takeaways
- CN102712584 covers specific crystalline polymorphs of rosuvastatin calcium, defined by XRPD profiles, with claims encompassing preparation and pharmaceutical application.
- The patent landscape contains multiple patents on polymorphs and processes, often with narrow scopes, leading to potential workarounds.
- Strategic R&D should focus on developing alternative polymorphs or processes to avoid infringement.
- Enforcement of CN102712584 depends on the crystallographic data matching the claimed forms.
- The overall IP environment emphasizes the importance of detailed characterization and specific claims for solid forms in Chinese drug patenting.
FAQs
Q1: Can other crystalline forms of rosuvastatin calcium infringe on CN102712584?
A: Only if they match the XRPD patterns specified in the claims. Different polymorphs with distinct physical properties are less likely to infringe.
Q2: How does the narrow scope of polymorph claims affect patent enforcement?
A: Enforcement is limited to forms matching the detailed XRPD profiles. Developing alternative polymorphs avoids infringement.
Q3: Are process patents relevant to polymorph development?
A: Yes. They can cover manufacturing methods for different polymorphs, serving as barriers or avenues for licensing.
Q4: Can a generic drug developer bypass CN102712584?
A: Potentially, by creating a polymorph with different XRPD features or using a different synthesis process.
Q5: How does the patent landscape impact R&D strategies in China?
A: It encourages designing around existing patents via new crystalline forms or innovative manufacturing methods to maintain freedom to operate.
References
- Chinese Patent Office. (2012). CN102712584. Polymorphic forms of a compound and uses thereof.
- Chinese Patent Office. (2010). CN102007459. Crystalline form of rosuvastatin calcium.
- Chinese Patent Office. (2015). CN105586359. Process for preparing rosuvastatin salt.
