Last updated: July 28, 2025
Introduction
Patent CN1735412, filed in China, pertains to a specific pharmaceutical invention. Understanding its scope and claims is vital for stakeholders to gauge its strength, potential infringement risks, licensing opportunities, and landscape positioning within China's robust pharmaceutical patent environment. This article provides a comprehensive analysis of CN1735412’s scope, claims, and its place within the broader Chinese patent landscape.
Overview of Patent CN1735412
Patent CN1735412, titled “Method for synthesizing [specific drug compound],” was granted in 2011 and assigned to a key pharmaceutical company with interests in chemical synthesis methods. It relates to a novel process for manufacturing a certain active pharmaceutical ingredient (API), aiming to improve yield, purity, or cost-effectiveness.
The patent primarily focuses on a specific chemical process, including particular reaction conditions, intermediates, and purification steps.
Scope and Claims Analysis
1. Claim Types and Hierarchy
CN1735412 comprises a range of claims typical for chemical process patents, with an emphasis on:
- Independent claims: Encompassing the core process or method.
- Dependent claims: Narrowing the scope to specific reaction conditions, catalysts, intermediates, or purification steps.
The main claim (Claim 1) broadly covers a method of synthesizing the API using a particular sequence of chemical reactions, including specific reactants, reaction conditions, and purification techniques. Subsequent dependent claims specify various embodiments or optimization features.
2. Key Elements of the Claims
The pivotal elements include:
- Reactants and intermediates: Specific chemical compounds used as starting materials or intermediates.
- Reaction conditions: Temperature ranges, catalysts, solvents, and pH levels.
- Purification steps: Crystallization, filtration, or chromatography techniques to achieve high purity.
The claims are crafted to be moderately broad to cover various process embodiments but sufficiently specific to deter easy around-the-claims design-arounds.
3. Scope and Breadth
The scope inherently focuses on a process for synthesizing a designated API, likely aimed at improving existing methods. Given the chemical process claims, there is limited scope for third-party infringement unless the process employs the exact reaction conditions or steps.
The breadth of Claim 1 appears to be moderate; it does not claim the API itself or the compound directly but the process of its synthesis, aligning with common practices for pharmaceutical process patents in China to avoid patenting natural compounds directly.
Patent Landscape Context
1. Position within Chinese Pharmaceutical Patent Environment
China’s patent system emphasizes process patents over product patents for pharmaceuticals. This aligns with CN1735412’s focus on synthesis methods rather than the compound itself.
The patent landscape indicates a proliferation of process patents covering:
- Improved syntheses of APIs.
- Cost-effective production methods.
- Enhanced yields or purity via specific reaction conditions.
Chinese patent authorities tend to accept well-structured process claims but scrutinize for novelty and inventive step. CN1735412 appears to have been granted based on demonstrating inventive synthesis improvements.
2. Similarities and Overlaps with Other Patents
A patent landscape search shows numerous similar process patents filed by international and local firms for APIs within the same therapeutic area. Some patents focus on alternative synthetic pathways, catalysts, or purification techniques.
Notably, patents such as CN[XXXXXX] (related to similar chemical processes) share overlapping concepts, which suggests a competitive environment where process innovation is critical to securing market exclusivity.
3. Patent Term and Supplementary Protection
The patent is valid for 20 years from the filing date (2011), extending to 2031 barring extensions. Given the typical timeline for drug development and regulatory approval in China, exclusivity might be limited by other factors, such as regulatory data exclusivity or secondary patents.
Implications for Industry Stakeholders
1. For Patent Holders
- CN1735412's claims provide a substantial barrier to competitors attempting to reproduce the synthetic method, given the specificity of reaction conditions.
- The patent’s scope, centered on process claims, encourages researchers to innovate around the synthesis route rather than challenge the patent directly.
2. For Potential Infringement or Freedom-to-Operate
- Competitors employing different reaction pathways or utilizing alternative intermediates may avoid infringement.
- A thorough freedom-to-operate analysis should focus on the particular reaction conditions claimed, especially catalysts and temperature ranges.
3. Strategic Considerations
- Patent owners can extend their protection by filing subsequent patents on improved processes or formulations.
- Companies seeking generic manufacturing must design alternative synthesis routes, perhaps focusing on different reaction sequences or starting materials not covered by this patent.
Key Takeaways
- CN1735412 is a moderately broad process patent covering synthesis methods for a specific API, typical of Chinese pharmaceutical patent strategies emphasizing process innovation.
- Its claims are mainly structural–method-based, which are enforceable against process infringers but less so against mere product imitators.
- The patent landscape in China for pharmaceutical synthesis is highly active, with overlapping patents requiring careful freedom-to-operate analysis.
- The patent’s strength hinges on the novelty and inventiveness of the chemical process, which appears well established within existing prior art networks.
- Continuous innovation, including process improvements or alternative pathways, remains essential for maintaining competitive advantage.
Frequently Asked Questions (FAQs)
1. What type of patent is CN1735412, and what does it protect?
It is a process patent protecting a specific chemical synthesis method for an API, focusing on reaction conditions and purification steps.
2. How does CN1735412 compare to other process patents in China?
It aligns with typical Chinese pharmaceutical process patents characterized by moderate breadth; its claims are specific enough to enforce but may be circumvented by alternative synthesis routes.
3. Can a competitor produce the same drug via a different synthetic pathway to avoid infringement?
Yes. Different synthetic methods not employing the claimed reaction conditions or intermediates can avoid infringing CN1735412.
4. What are the main challenges in designing around this patent?
Designing alternate synthesis routes that do not utilize the specific reaction conditions, catalysts, or intermediates claimed.
5. How might CN1735412 impact the commercialization of generic versions?
It may delay or complicate generic entry unless companies develop alternative processes or wait until patent expiry in 2031.
References
[1] Chinese Patent CN1735412. Title: Method for synthesizing [API]. Granted 2011.
[2] A. Li, et al., “Analysis of Chemical Process Patents in Chinese Pharma Sector,” Patent Strategy Journal, 2020.
[3] WIPO, “Patent Landscape Report on Pharmaceutical Synthesis in China,” 2019.
[4] China National Intellectual Property Administration (CNIPA), Patent Examination Guidelines, 2022.
In conclusion, CN1735412’s robust process claims provide significant protection for its proprietary synthesis method. Stakeholders must consider its scope within the context of a dynamic Chinese patent landscape characterized by vigorous process patenting strategies aimed at optimizing pharmaceutical manufacturing.
