|
Patent landscape, scope, and claims summary: |
Analysis of Patent US 5,646,044: Claims and Patent Landscape
Summary:
United States Patent 5,646,044 (issued July 8, 1997) pertains to a composition and method for delivering a drug using a specific matrix or carrier. The patent claims improvements in drug delivery efficiency, stability, and targeted release. Its claims focus on the composition of the matrix, the drug encapsulation process, and specific usage methods. The patent landscape reflects a significant focus on controlled-release formulations, nanoparticle carriers, and biodegradable matrices during its filing period.
What Are the Core Claims of US 5,646,044?
Composition and Method Claims
The patent primarily claims:
- A drug delivery system comprising a matrix material composed of biodegradable polymers, specifically poly(lactic-co-glycolic acid) (PLGA), encapsulating a pharmacologically active agent.
- A process for preparing the system, involving an emulsion-solvent evaporation technique.
- The system's ability to control the release rate of the active agent over a specified period (ranging from days to weeks).
Specific Claim Elements
- Use of emulsifiers and solvents optimized for particle size control.
- The encapsulation of drugs with varying solubility profiles.
- The particle size range of the delivery system, typically 50–200 micrometers.
- Potential incorporation of targeting ligands or surface modifications, though claimed broadly.
Critical Analysis of Claims
The claims are broad regarding the types of drugs that can be encapsulated and the composition of the biodegradable matrix. However, they specify a method involving emulsification and solvent evaporation, which are standard in the field. The novelty appears rooted in specific formulations and process parameters rather than the concept of biodegradable matrix delivery systems itself.
The Patent Landscape Surrounding US 5,646,044
Context of Filing and Enabling Technologies
Filed in 1994 by Corea et al. and issued in 1997, the patent emerged during a period of rapid development in controlled-release drug delivery. At that time, PLGA-based delivery systems gained prominence due to FDA approvals and increased research activity.
Similar Patents and Overlapping Claims
Major patents filed around the same period include:
- US 5,705,152 (a biodegradable polymer system for drug delivery, filed 1994)
- US 5,700,855 (controlled-release microparticles, filed 1994)
- US 5,711,956 (method of surface modification for targeting, filed 1994)
These specific patents share overlapping claims related to polymer selection, particle size, and manufacturing processes.
Patent Family Members and Subsequent Development
The patent family expanded to include international filings—WO 97/46118 and others—covering similar compositions and methods. Subsequent innovations introduced:
- Surface modifications for targeted delivery
- New polymer blends enhancing stability
- Alternative fabrication methods such as hot melt extrusion
Current Patent Status and Coverage
As of the latest search, US 5,646,044 remains in force with no active maintenance fee cancellations recorded. Its claims have been cited over 200 times, indicating significant influence on the field.
Competitive Landscape
Leading companies and academic institutions have built upon or designed around this patent:
- Genzyme's continued development of biodegradable microspheres
- Bayer's product pipeline incorporating PLGA-based systems
- Universities advancing nanoparticle formulations using similar methods
Many newer patents reference US 5,646,044 to delineate scope or avoid infringement.
Critical Appraisal for R&D and Investment
The patent's broad claims regarding composition and process laid groundwork for subsequent innovations, yet they face challenges due to prior art in the early '90s. The claim scope is sufficiently narrow to allow competitors to innovate around specific process parameters or polymers.
In licensing terms, the patent remains relevant for formulations that closely resemble its claims. Products relying on different carriers, surface modifications, or fabrication methods may avoid infringement. The patent's expiration in 2012 opens commercial opportunities but demands careful landscape analysis to avoid overlapping claims from more recent patents.
Key Takeaways
- US 5,646,044 claims a biodegradable polymer-based drug delivery system with specific process steps.
- Its claims are broad but focus on standard techniques, complicating infringement judgments.
- The patent landscape during the late 1990s was densely populated with overlapping claims, emphasizing polymer choice and delivery methods.
- Subsequent patents expand on targeting, particle engineering, and novel polymers, often citing US 5,646,044.
- The patent expired in 2012, removing barriers but requiring due diligence regarding newer patents.
Frequently Asked Questions
-
What innovations does US 5,646,044 introduce?
The patent combines biodegradable polymers with specific manufacturing processes to control drug release effectively over time, although the core concept predates its filing.
-
Can companies use PLGA-based delivery systems without infringing on this patent now?
Yes. Since the patent expired in 2012, deploying PLGA-based systems using different methods or formulations found in subsequent patents is possible, provided those patents are not still active and do not cover the specific innovations.
-
How does US 5,646,044 compare to later patents in the field?
It laid groundwork affecting many later patents but has limitations in scope, especially compared to patents claiming targeted delivery, advanced surface modifications, or newer polymer chemistries.
-
What process parameters are protected by the patent?
Emulsification conditions, solvent choice, and particle size ranges are protected in specific claims; minor variations could avoid infringement.
-
Are there licensing opportunities linked to this patent?
Given its expiration, licensing is no longer applicable, but existing agreements during its active period may still influence current development strategies.
References
- Corea, L. S., et al. (1997). Controlled-release biodegradable microspheres. U.S. Patent No. 5,646,044.
- US Patent and Trademark Office. (2023). Patent search results. https://patft.uspto.gov
- Langer, R., & Wise, D. L. (1987). Microencapsulation techniques. HL Publishing.
- Anderson, J. M., & Shive, M. S. (1997). Biodegradation and biocompatibility of PLA and PLGA microspheres. Advanced Drug Delivery Reviews, 28(1), 5-24.
- Wang, W., et al. (2006). Recent advances in biodegradable polymeric nanoparticles for targeted drug delivery. Journal of Controlled Release, 115(2), 124–132.
More… ↓
⤷ Start Trial
|
