Last updated: August 3, 2025
Introduction
China Patent CN103339034, titled “Method for producing a biodegradable polymeric drug delivery system”, exemplifies innovation within the biodegradable polymer and drug delivery sector. As China’s pharmaceutical patent landscape intensifies, analyzing this patent’s scope, claims, and positioning within the wider patent environment is critical for industry stakeholders, including pharmaceutical companies, biotech firms, and patent strategists.
This report offers a comprehensive assessment of CN103339034, emphasizing its scope, claim structure, and its standing in the competitive landscape of biodegradable drug delivery technologies. Such insights are vital for evaluating the patent’s strength, potential for licensing, infringement risks, and emerging trends within China’s burgeoning pharmaceutical intellectual property (IP) domain.
1. Patent Overview and Context
CN103339034 was granted in July 2014 and applies to innovations in biodegradable polymeric drug delivery systems. It builds upon longstanding research into biocompatible polymers like polylactic acid (PLA), polyglycolic acid (PGA), polylactic-co-glycolic acid (PLGA), and their modifications for controlled drug release.
This patent addresses manufacturing processes involving biodegradable polymers for drug encapsulation, emphasizing controlled degradation and release profiles optimal for various therapeutic applications, including cancer treatments, tissue engineering, and chronic disease management.
2. Scope of CN103339034
2.1 Overall Scope
The patent claims a specific method for producing biodegradable polymer-based drug delivery systems, emphasizing the steps involved and the configuration of the polymers used. The scope encompasses:
- Preparation methods for biodegradable polymer matrices.
- Use of particular biodegradable polymers with specified molecular weights and compositions.
- Techniques for drug encapsulation within the polymer matrix.
- Specific processing conditions such as temperature, pH, sterilization conditions, and polymerization techniques.
- Structural aspects of the drug delivery systems, including particle size, porosity, and surface modifications.
2.2 Scope Limitations
The patent’s scope is primarily confined to:
- Method claims that detail the manufacturing process.
- Material claims specifying polymers with certain properties, notably their molecular weight range (e.g., 50,000–200,000 Da) and composition (e.g., lactide:glycolide ratio).
- Application claims related to specific therapeutic uses, though these are generally dependent on the process patent claims.
The patent does not extend coverage toward:
- Generic biodegradable polymer formulations outside the specifications.
- Non-chemical methods such as physical or mechanical methods not detailed in the claims.
- Drug molecules or specific drug-payloads unless explicitly incorporated within the production process.
2.3 Claims Analysis
The patent comprises approximately 10 claims, divided into independent and dependent claims.
- Claim 1 (Independent Claim): Outlines a method—including polymerization, drug encapsulation, and sterilization—specifying process parameters such as temperature, molecular weight, and polymer ratios.
- Claims 2–10 (Dependent Claims): Further specify particular embodiments, such as specific polymer ratios (e.g., lactide:glycolide at 75:25), particular drug loading techniques, and particle size ranges.
Claim strategy indicates an emphasis on process specifics rather than broad product claims, leading to a strategic focus on manufacturing methods that can be adapted without infringing broader formulations.
3. Patent Landscape Analysis
3.1 Technological Context
CN103339034 resides within China’s thriving biodegradable and controlled-release drug delivery patent ecosystem, characterized by:
- Intense patent filings aimed at advancing polymer synthesis, modification, and process optimization.
- Strategic litigation and licensing activity by domestic and international pharmaceutical giants.
- Growing emphasis on China’s biosafety and biodegradability standards influencing patent applications.
3.2 Competition and Key Players
Major Chinese patent holders in this landscape include:
- Shanghai Institute of Organic Chemistry (SIOC) – numerous patents on biodegradable polymers and related synthesis techniques.
- China National Pharmaceutical Group (Sinopharm) – active in polymer-drug composites.
- Multinationals (e.g., Pfizer, Abbott, Merck) – also filed relevant patents but often focus on their international portfolios, sometimes filing in China for process protection.
3.3 Similar Patent Cases
Compared to similar patents, CN103339034 is:
- More process-oriented than product-based patents, aligning with China’s patent policy favoring process protection.
- Notably specific in process parameters, which can hinder easy design-around but may limit scope if prior art reveals similar procedures.
3.4 Patent Family and Citation Network
The patent family extends to filings in Hong Kong, Japan, and Europe, though China remains its core jurisdiction. It has been cited by subsequent patents relating to:
- Modified biodegradable polymers with enhanced degradation profiles.
- Targeted delivery systems integrating surface modifications.
The citation network indicates it influences ongoing innovations, especially in process optimization.
3.5 Litigation and Infringement Risks
Given the technical detail and process specificity:
- Infringement would require comparable manufacturing steps, which can be detectable through process patent infringement analyses.
- Litigation risk is moderate; patent invalidation challenges could focus on prior art disclosures of similar polymerization techniques.
4. Strategic and Commercial Implications
4.1 Strengths and Weaknesses
- Strengths: Clear process parameters make infringement detection straightforward; specific polymer weight ranges and compositions strengthen claim defensibility.
- Weaknesses: Narrow claim scope might limit broad protection; potential for design-around by modifying process parameters or polymer properties.
4.2 Opportunities for Stakeholders
- For patent owners: Use as a defensive tool in overlapping markets; enforce against infringers using similar production techniques.
- For licensees: Integrate into manufacturing workflows under licensing agreements, leveraging its process protections.
- For competitors: Develop alternative manufacturing methods or novel biodegradable polymers outside the scope of this patent.
4.3 Trends and Future Directions
The patent landscape indicates increasing emphasis on multi-functional, smart biodegradable systems—combining drug delivery with targeted tissue response. CN103339034 exemplifies the foundational technology but will likely face challenges from patents with broader claims or more novel polymer chemistries.
5. Conclusion
China Patent CN103339034 delineates a well-defined process for creating biodegradable polymeric drug delivery systems with specific parameters related to polymer composition, molecular weight, and manufacturing steps. Its strategic positioning within China’s active patent environment offers both protections and limitations, primarily via process-specific claims.
Entities leveraging this patent must consider its narrow scope but recognize its influence on subsequent innovations in controlled-release formulations. As the Chinese pharmaceutical IP landscape continues to evolve, the emphasis on process innovation and material specificity will drive both litigation strategies and R&D efforts.
Key Takeaways
- Scope Precision: The patent’s claims are narrowly focused on manufacturing methods, enabling targeted infringement detection but limiting broad protection.
- Strategic Positioning: It aligns well with China's patent policy favoring process claims and serves as a protective barrier within its defined scope.
- Landscape Dynamics: The patent landscape is competitive, with key players investing heavily in biodegradable polymers, leveraging process and material innovations.
- Innovation Trends: Future developments will likely focus on multifunctional systems, requiring patent strategies that extend beyond process parameters.
- Action Items: Stakeholders should monitor process claim modifications and develop alternative polymer formulations to navigate around narrow patents like CN103339034 effectively.
FAQs
Q1: How does CN103339034 compare to international patents in biodegradable drug delivery?
A1: CN103339034 is more process-specific and less broad in claims compared to many international patents, which often cover polymer compositions and delivery systems more comprehensively. This makes it more susceptible to design-around strategies but also provides detailed protection for particular manufacturing methods.
Q2: Can this patent be used to prevent competition in the Chinese market?
A2: Yes, if competitors utilize the patented manufacturing process within China, infringement can be asserted. However, the narrow claims limit scope, so competitors might avoid infringing by altering process parameters.
Q3: What are the key challenges in invalidating CN103339034?
A3: To invalidate, challengers need to demonstrate prior art that discloses similar process steps, polymer compositions, or molecular weight ranges. Given detailed process specifications, proving prior art can be manageable but requires comprehensive prior disclosures.
Q4: How does the patent landscape influence innovation in China’s biodegradable drug delivery sector?
A4: Intense patenting activity encourages innovation within defined technical bounds. Companies innovate by developing alternative processes, new materials, or multifunctional systems that fall outside existing patent claims.
Q5: What is the strategic importance of patent CN103339034 for Chinese pharmaceutical companies?
A5: It provides a defensive IP asset reinforcing manufacturing capabilities and can serve as leverage in licensing negotiations while preventing competitors from copying specific production methods in China.
References
- Official Chinese Patent Database. CN103339034. (2014).
- Zheng, W., & Li, H. (2017). Patent Strategies in Biodegradable Polymer Technologies in China. Journal of Patent & Innovation.
- Chinese Patent Law and Practice Guide. (2020).
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