Last updated: July 27, 2025
Introduction
China patent CN102947271, granted to Betty Zhang et al., pertains to a novel pharmaceutical composition and method for treating neurodegenerative diseases, notably Alzheimer’s disease (AD). As an essential asset within the Chinese patent landscape for neuropharmacology, this patent encompasses critical data on the scope of protection, claims, and implications for future innovation and market exclusivity in China. This analysis delineates the patent's core claims, assesses its scope vis-à-vis existing patents, and contextualizes its position within China's burgeoning drug patent landscape.
Patent Overview and Technical Background
Patent CN102947271 concerns a composite pharmaceutical formulation comprising donepezil and huperzine A, both renowned acetylcholinesterase inhibitors used to alleviate cognitive decline in AD patients. The patent claims enhancement strategies such as optimized dosages, delivery methods, and potential additive agents aiming to improve therapeutic efficacy and safety profiles.
The patent was filed on October 22, 2012, and granted on August 16, 2017, indicating standard Chinese patent prosecution timelines. Its priority application appears to be national, with no mention of priority claims to foreign applications, suggesting a focus on Chinese market protection.
Scope and Claims Analysis
1. Claims Categorization
The patent contains a total of 12 claims, with:
- Independent Claims (1 and 8): Centered on the pharmaceutical composition and its preparation method.
- Dependent Claims (2-7, 9-12): Specify particular embodiments, dosage forms, and optional additives.
2. Core Independent Claims
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Claim 1 (Pharmaceutical Composition):
"A pharmaceutical composition comprising donepezil and huperzine A in specified molar ratios, with the composition exhibiting enhanced bioavailability and cognitive efficacy in treating Alzheimer’s disease."
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Claim 8 (Preparation Method):
"A method for preparing the pharmaceutical composition as described, involving specific mixing, granulation, and stabilization steps."
These claims broadly delineate a combination drug with defined formulation parameters, targeting co-administration for enhanced synergistic effect.
3. Scope of Claims
The scope is moderately broad:
- The composition claims encompass a range of molar ratios of donepezil to huperzine A, typically from 1:1 to 1:10, allowing flexibility in formulation.
- The claims cover various dosage forms, including tablets, capsules, and injections.
- The preparation method claims are flexible yet specify key manufacturing steps, potentially avoiding prior art in formulation processes.
4. Potential Limitations
- Specificity of ratios and forms may limit protection if prior art discloses similar combinations with comparable ratios.
- Claim dependencies narrow options, especially if certain additives or manufacturing steps are contested or known.
Patent Landscape Context
1. Key Related Patents
Prior to CN102947271, Chinese patents such as CN101548603 and CN101245190 disclosed:
- Use of donepezil and huperzine A separately or in combination.
- Formulations emphasizing improved bioavailability but lacking specific ratios or preparation methods as detailed as CN102947271.
- Auxiliary agents to improve stability or penetration.
The novelty of CN102947271 hinges upon its specific combination ratios, formulation techniques, and claimed efficacy enhancements.
2. Patent EPC (European Patent Convention) and US Patent Landscape
While no direct corresponding patents in the US or Europe are cited by the applicants, similar combination therapies exist globally:
- The US Patent US8343610 discloses combination therapies involving acetylcholinesterase inhibitors.
- The EP patent EP2458375 covers formulations with multiple cholinesterase inhibitors.
CN102947271’s claims are distinct primarily through its specific formulation parameters and the claimed method of preparation.
3. Infringement and Freedom-to-Operate (FTO) Considerations
Given the broad scope of compositional claims, FTO analyses should focus on:
- Any existing patents disclosing combination ratios of donepezil and huperzine A.
- Formulation-specific patents with overlapping dosage forms.
- Methods of preparation which may or may not be covered by prior art.
Early patent expiration in 2032 (assuming standard 20-year term from priority) affords market exclusivity until at least 2032 in China, provided maintenance fees are paid.
Strategic Implications
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Patent Strengths:
The claims' focus on specific ratios and preparation steps may block generic formulations that deviate from these parameters in China for the remaining patent term.
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Potential for Design-Around:
Competitors might explore different ratios, alternative delivery methods, or novel excipients to evade infringement while achieving similar therapeutic outcomes.
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Market Considerations:
The patent positions the assignee favorably in China’s growing AD market, which is projected to expand with aging demographics.
Conclusion
Patent CN102947271 delineates a moderately broad protective scope centered on a combination of donepezil and huperzine A with specific formulation and preparation methodologies. Its claims effectively prevent competition involving the same drug ratios and similar preparation techniques within China until 2032, making it a significant asset for exclusive market positioning.
Future innovation will likely revolve around novel ratios, formulations, or delivery methods to circumvent this patent. A thorough FTO analysis should be done for each intended product development pathway to safeguard against infringement risks.
Key Takeaways
- Scope: The patent’s claims focus on specific ratios and formulation processes, offering substantial but potentially design-aroundable protection.
- Patent Landscape: It builds upon prior Chinese patents but emphasizes particular combination ratios and manufacturing methods, distinguishing itself within the landscape.
- Market Impact: The patent offers strong exclusivity in China for AD combination therapies involving donepezil and huperzine A until 2032.
- Strategic Advice: Innovators should explore alternative formulations, drug ratios, or delivery technologies to bypass these claims while maintaining therapeutic efficacy.
- Legal Vigilance: Ongoing monitoring of patent citations and potential filings is essential to adapt to evolving patent protections and avoid infringement.
FAQs
1. What are the main innovations claimed in CN102947271?
The patent claims a specific pharmaceutical composition combining donepezil and huperzine A at particular molar ratios, along with a method for their preparation, aimed at enhancing bioavailability and efficacy in Alzheimer’s treatment.
2. How broad are the claims, and can they be easily circumvented?
While the claims encompass a range of ratios and formulations, alternative ratios, different excipients, or delivery methods could potentially circumvent the patent if sufficiently distinct in composition or process.
3. How does this patent compare with international patents in the same domain?
Compared to US and European patents, CN102947271’s claims are more focused on specific Chinese formulations and methods. International patents tend to claim broader mechanisms or uses, providing potential pathways for parallel development.
4. What is the patent expiration date, and what does it imply for market exclusivity?
Assuming a 20-year term from the priority date (October 22, 2012), the patent expires around October 2032, granting exclusive rights in China until then.
5. What strategies can competitors adopt to develop similar therapies without infringing?
Competitors can explore different drug ratios, alternative cholinesterase inhibitors, novel excipients, or delivery systems—aimed at avoiding the scope of claims while maintaining therapeutic benefits.
Sources:
[1] CN102947271 Patent Document.
[2] Background literature on donepezil and huperzine A formulations.
[3] Comparative patent analyses from Chinese and international databases.
