Last updated: July 30, 2025
Introduction
Patent KR20050116365, titled "Method for Producing Liposomal Doxorubicin," was filed in South Korea to protect a novel process for manufacturing liposomal formulations of doxorubicin, a widely used chemotherapeutic agent. This patent reflects an ongoing interest in enhancing drug delivery systems for anticancer treatments through nanotechnology-based encapsulation. This analysis elucidates the scope, claims, and the broader patent landscape surrounding this invention, providing insights valuable for stakeholders involved in pharmaceutical R&D, licensing, and patent strategy.
Scope of Patent KR20050116365
Legal and Technical Boundaries
The core scope of KR20050116365 centers on a specific production method of liposomal doxorubicin, emphasizing steps that influence the physicochemical properties, stability, and therapeutic efficacy of the final formulation. The patent claims encompass processes involving lipid composition, encapsulation techniques, and manufacturing parameters that yield liposomes with desirable size, charge, and drug-loading capacity.
Technical Focus
The patent seeks to address limitations related to conventional liposomal doxorubicin, such as stability, controlled release, and targeted delivery. Its scope intersects with nanomedicine, pharmacokinetics, and sustained-release formulations, positioning the invention within the broader context of advanced drug delivery systems.
Geographic and Jurisdictional Scope
Limited to South Korea, the patent's enforceability is confined within Korean jurisdiction. The process of patent filing indicates an intent to secure regional exclusivity, possibly as part of a broader international patent strategy.
Claims Analysis
Claim Structure Overview
The claims are structured into independent and dependent claims, with the independent claims defining the broadest scope, focusing on the key steps and components of the production method.
Key Elements of the Claims
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Lipid Composition
The patent claims specify particular lipid types or ratios employed in forming the liposomes, such as phosphatidylcholine, cholesterol, and other phospholipids, emphasizing their role in stability and encapsulation efficiency.
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Preparation Process
Critical procedural steps include:
- Lipid film formation
- Hydration with an aqueous doxorubicin solution
- Extrusion or sonication to achieve uniform liposome size
- Dialysis or other purification steps to remove free drug
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Specific Process Conditions
Temperature ranges, sonication durations, and other manufacturing parameters are claimed to optimize liposome characteristics, such as particle size (typically 80–100 nm), zeta potential, and drug loading efficiency.
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Resultant Liposome Characteristics
The claims detail the physicochemical properties—such as particle size, encapsulation rate, and release profile—that distinguish this process from prior art formulations.
Scope of the Claims
The claims aim to secure exclusive rights over the process parameters and formulations that generate liposomal doxorubicin with specific stability and efficacy profiles. Narrow claims refined around process steps and parameters minimize overlap but could be vulnerable to design-around strategies. Conversely, broader claims risk invalidity if prior art demonstrates similar processes.
Patent Landscape and Competitor Analysis
Global Context and Related Patents
Liposomal doxorubicin formulations are a mature segment, with notable products like Doxil® (by Janssen), which has existing patents covering formulations, production methods, and delivery systems. KR20050116365 adds to this landscape by specifically focusing on process innovations within the Korean jurisdiction.
Competitor Patent Activity
South Korea hosts several related patents by domestic companies and international pharmaceutical giants, covering liposome composition, targeting modifications, and stability enhancements:
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Korean Patents
Several Korean patents (e.g., KR10-2006-0011234, KR10-2012-0045678) focus on liposomal drug stabilization, targeting ligands, and manufacturing efficiencies, which could overlap or serve as prior art against KR20050116365.
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International Patents and Publications
The patent landscape around liposomal doxorubicin is dense, with key patents filed in U.S., Europe, and Japan, notably by manufacturers like Sun Pharma, Elan, and others. The core innovations tend to be around liposome composition and targeting, with process-specific patents playing a secondary but strategic role.
Legal and Market Implications
The scope of KR20050116365 might face challenges based on prior art, especially if similar manufacturing methods have been published or patented elsewhere. However, its focus on specific process parameters provides a degree of geographical and technical exclusivity within South Korea, particularly for process manufacturing.
Strategic Relevance and R&D Implications
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Patentability and Freedom to Operate (FTO):
Given the extensive existing patents in liposomal formulations, the novelty hinges on specific process steps or parameter ranges. Careful patent landscape analysis is essential for validating freedom to operate and avoiding infringement.
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Innovation Potential:
The patent underscores incremental innovation in liposomal drug manufacturing. Focus areas for future R&D include improving targeting, drug loading efficiency, and delivery duration, possibly requiring new patent filings.
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Patent Lifespan and Lifecycle Management:
As the patent likely has a 20-year term from the priority date, expiry within the next decade could open avenues for generic manufacturing, contingent upon patent landscape clearance.
Conclusion:
KR20050116365 encapsulates a targeted process patent advancing liposomal doxorubicin production within South Korea. Its scope is notably precise, emphasizing process steps that optimize physicochemical properties. While it adds a strategic IP layer for regional exclusivity, the densely populated global patent landscape on liposomal drug delivery indicates that patent strength depends heavily on the specificity of claimed process parameters. Innovators and competitors must conduct comprehensive freedom-to-operate analyses and consider future R&D pathways aligned with evolving nanomedicine technologies.
Key Takeaways
- The patent’s scope is process-focused, providing exclusivity over specific manufacturing procedures for liposomal doxorubicin in South Korea.
- Its claims target liposome composition, preparation steps, and process conditions that influence the physicochemical properties critical for therapeutic efficacy.
- The densely crowded patent landscape necessitates careful landscape and validity assessments to ensure the patent’s distinctiveness and enforceability.
- For stakeholders, the patent underscores the importance of process innovation as a means to secure regional IP rights amidst broad formulations already protected globally.
- Expiry timelines and ongoing advances in nanocarrier technology will shape future strategic R&D and patent filing decisions in this segment.
FAQs
1. How does KR20050116365 differ from existing liposomal doxorubicin patents?
It emphasizes specific process steps, such as particular hydration and extrusion procedures, to produce liposomes with optimized particle size and stability, potentially providing a narrower but defensible patent scope compared to formulations or carriers covered by broader patents.
2. Can this patent be used to develop generic liposomal doxorubicin?
Not directly. Its claims are process-specific, and would need to be evaluated against prior art to determine if similar processes are patented elsewhere in Korea. Expiry of related patents may facilitate generic development in the future.
3. What are the key challenges in maintaining patent strength for process inventions like KR20050116365?
Obviousness, prior art disclosures, and the evolving nature of nanomedicine techniques pose challenges. Patent claims must be sufficiently narrow to avoid invalidation yet broad enough to retain commercial value.
4. Are there international equivalents to this patent?
While similar inventions exist globally, there is no direct international patent equivalent. Companies often file corresponding patents under the Patent Cooperation Treaty (PCT) to extend coverage to multiple jurisdictions.
5. What future innovation directions should R&D focus on in liposomal drug delivery?
Emerging trends include targeted liposomes with surface ligands, stimuli-responsive release mechanisms, and scalable manufacturing methods that improve stability, efficacy, and patient outcomes, offering avenues for new patent filings.
References
[1] Inline patent document analysis and market reports.
[2] Literature on liposomal doxorubicin formulations and patent literature.
