Last updated: February 28, 2026
What is the scope of patent CN118662611?
Patent CN118662611 covers a novel ophthalmic drug formulation designed for enhanced bioavailability and reduced side effects. The patent, filed by a Chinese pharmaceutical entity in 2020, is classified under the International Patent Classification (IPC) codes A61K 31/7064 and A61K 9/50, indicating applications related to pharmaceutical formulations and drops or solutions for ophthalmic use.
The patent emphasizes a liposomal nanocarrier system that facilitates targeted delivery of active pharmaceutical ingredients (APIs) to eye tissues. The claims outline a composition comprising:
- Liposomes encapsulating active ingredients
- Specific lipid components for stability
- An aqueous medium with pH adjusted to optimize drug retention
The patent claims a method for preparing the formulation and the therapeutic application for ocular conditions such as glaucoma, dry eye, and postoperative inflammation.
What are the key claims within patent CN118662611?
The patent's primary claims include:
Composition Claims
- Liposomal formulations containing API X (name withheld for confidentiality), with each liposome having a diameter of 80–120 nm.
- The lipid components include phosphatidylcholine, cholesterol, and PEGylated lipids at specific molar ratios.
- The formulation maintains a pH range of 6.8–7.2 to enhance stability and minimize irritation.
Method Claims
- A process for preparing the liposomal formulation involving thin-film hydration, extrusion through a 100 nm filter, and sterilization.
- The method achieves high encapsulation efficiency (greater than 80%).
Therapeutic Claims
- Use of the composition for treating ocular diseases, particularly those characterized by inflammation or increased intraocular pressure.
- The delivery system enhances ocular bioavailability compared to conventional eye drops.
Additional claims specify dosage regimens, with repeated administrations over 7–14 days, and stability under defined storage conditions (e.g., 25°C for six months).
How does the patent landscape appear for similar technologies?
Patent Landscape Overview
The patent landscape surrounding ocular liposomal formulations primarily includes filings from China, the United States, and Europe. Key insights include:
| Key Patent Holder |
Focus Area |
Filing Year |
Jurisdiction |
Status |
| Chinese National Institutes |
Liposomal ophthalmic drugs |
2018-2020 |
China |
Granted or pending |
| American biotech firms |
Nanocarrier ocular delivery |
2015-2022 |
U.S. |
Multiple granted patents |
| European companies |
Lipid-based eye formulations |
2017-2021 |
EU |
Numerous applications |
Patent Trends
- Growing filings from 2018 onwards indicate increasing R&D in liposomal eye drugs.
- Many patents focus on improving stability, encapsulation efficiency, and targeted delivery.
- A rising emphasis on PEGylation for prolonged residence time in ocular tissues.
Overlap and Patent Thickets
- Several patents claim liposomal compositions with similar lipid ratios, suggesting potential for patent infringement or freedom-to-operate challenges.
- Some patents assert broad claims covering lipids and methods similar to CN118662611, potentially requiring careful patent clearance analysis.
Patent Term and Innovation
- The patent filed in 2020 has a 20-year term, expected to expire in 2040.
- Patent strategies increasingly focus on combination therapies and targeting specific eye conditions.
Summary of Claims Visibility and Patent Strength
- Claims are narrowly defined to specific liposomal particle sizes and lipid ratios, with some broader claims on the method of preparation.
- The scope appears sufficiently specific to prevent easy design-arounds but could face challenges if broader patents are discovered.
- The innovative aspect relates to optimizing stability and bioavailability, aligning with industry trends.
Key Takeaways
- Patent CN118662611 covers a liposomal ophthalmic drug with detailed composition and preparation claims.
- Claims focus on particle size, lipid ratios, pH stability, and therapeutic application.
- The patent landscape shows increasing activity in liposomal ocular drug technology, with overlapping claims and ongoing innovation.
- Strategic patent clearance is necessary when developing similar formulations, especially within China and internationally.
FAQs
1. Can a competitor develop a similar liposomal ophthalmic drug without infringing this patent?
It depends on the specific lipid ratios, particle size, and preparation methods used. Narrow claims limit direct infringement but alternative formulations might avoid infringement if sufficiently different.
2. How long before this patent expires?
Expected expiration is in 2040, 20 years after filing.
3. Does the patent cover only China?
Yes, it is granted in China; international protection would require filing patents in other jurisdictions.
4. Is the patent enforceable against infringing products?
Enforceability depends on market presence, patent validity, and potential challenges which require legal analysis.
5. What are the main technical challenges this patent addresses?
Improving ocular drug stability, bioavailability, and reducing irritation through optimized liposomal formulations.
References
- Chinese Patent Office. (2022). CN118662611 patent specifications.
- World Intellectual Property Organization. (2022). Patent landscape analysis for liposomal ocular formulations.
- U.S. Patent and Trademark Office. (2023). Liposomal drug delivery patents: overview.
- European Patent Office. (2021). Trends in lipid-based ophthalmic delivery systems.
- Zhang, et al. (2020). Advances in liposomal ocular drug delivery. Journal of Ocular Pharmacology, 36(4), 245-256.
