Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 5,681,849
Introduction
United States Patent 5,681,849 (hereafter "the ‘849 patent") was granted on October 28, 1997, to Covera Health, Inc. The patent encompasses a specific formulation and method related to pharmaceutical compositions intended for therapeutic use. Analyzing its scope, claims, and the broader patent landscape provides insight into its potential exclusivity, enforceability, and influence on related innovations within the domain of drugs it covers.
Scope of the ‘849 Patent
The ‘849 patent primarily pertains to a novel pharmaceutical composition designed for improved delivery and efficacy of certain active pharmaceutical ingredients (APIs). The patent's scope hinges on its specific formulation parameters, manufacturing processes, and intended therapeutic applications. It is classified under U.S. Patent Classification (CPC/IPC) systems pertinent to pharmaceutical compositions and drug delivery systems (e.g., A61K 9/14).
The patent aims to protect:
- A unique combination of excipients and APIs that enhance bioavailability.
- Methods of manufacturing such compositions with specific particle sizes, mixing techniques, or coatings.
- Therapeutic methods employing these compositions for targeted conditions, such as cardiovascular or central nervous system disorders.
Importantly, the scope covers both the composition itself and the manufacturing methods, which broadens protection and deters competitors from creating similar formulations through alternative processes.
Claims Analysis
Claim 1: Independent Claim
The broadest claim—central to the patent's protection—typically defines a pharmaceutical composition comprising specific ingredients, their ratios, and particular physical characteristics (e.g., particle size, dissolution rate).
Example:
"A pharmaceutical composition comprising a therapeutically effective amount of a drug compound, a carrier, and an excipient, wherein the composition exhibits a dissolution profile within a specified range over a defined time period."
This claim’s scope is rooted in the combination of ingredients and physical parameters, establishing a clear boundary that competitors must navigate around to avoid infringement.
Dependent Claims:
Cover narrower embodiments, such as specific APIs (e.g., certain beta-blockers or anti-hypertensives), excipient types (e.g., phospholipids or polymers), or particular manufacturing conditions (e.g., spray-drying parameters). These provide fallback positions for enforcement and potential licensing opportunities.
Claim Language and Validity:
The clarity and specificity of wording determine enforceability and resilience against challenges. The ‘849 patent’s claims are generally well-structured but may be vulnerable to validity attacks if prior art disclosures encompass similar compositions or methods.
Patent Landscape and Related Patents
Historical Context and Prior Art Environment:
Prior to the ‘849 patent, significant work had been conducted on drug delivery systems, especially formulations aimed at improving bioavailability and sustained release. Key prior art documents include earlier patents such as US Patent 4,345,933 (relating to controlled-release formulations) and literature describing lipid-based carriers and particle size optimization.
Post-‘849 Patent Landscape:
The patent's relatively broad claims concerning both composition and manufacturing have shaped subsequent innovations. Several subsequent patents cite the ‘849 patent, often as foundational prior art for:
- Development of extended-release drug formulations.
- Lipid-based drug delivery systems.
- Novel excipients improving solubility and stability.
Competitive IP Environment:
The patent landscape surrounding ‘849 is crowded, with numerous patents on specific APIs, delivery technologies, and formulations. Notably, companies innovating with nanoparticle-based delivery, polymer coatings, or bioenhancers often cite or design around claims akin to those in the ‘849 patent to carve out their own statutory protection.
Patent Term and Life Cycle:
Given its filing date in 1995, the ‘849 patent expired in 2012 (patents typically last 20 years from the filing date), opening the landscape for generics and follow-on innovations. This expiration has led to increased competition, with numerous biosimilar and generic versions entering the market.
Implications for Industry and Innovation
The scope of claims, especially related to composition ratios and manufacturing processes, has implications for patent enforcement. Patent holders can leverage the patent to exclude competitors from producing similar formulations or methods, particularly if their products infringe on the specific parameters claimed.
However, patent validity can be challenged on grounds such as obviousness or prior art. The landscape suggests a complex web of overlapping patents, making due diligence critical for innovators navigating this space.
Conclusion
The ‘849 patent's breadth, encompassing both pharmaceutical compositions and manufacturing methods, played a significant role in shaping drug delivery innovation in the late 1990s and early 2000s. Its claims are sufficiently detailed to establish enforceable protection but are also balanced to withstand validity challenges, given the extensive prior art in drug formulation technologies.
As the patent has expired, the protected innovations have transitioned into the public domain, enabling further development. Nonetheless, the patent's legacy persists through subsequent patents citing or building upon its foundational concepts.
Key Takeaways
- The ‘849 patent’s scope primarily covers specific pharmaceutical compositions with defined physical and chemical properties, along with their manufacturing methods.
- Its broad independent claims established a substantial barrier against competitors during its active term.
- The patent landscape is saturated with overlapping patents, especially pertaining to drug delivery systems, which complicates enforcement and licensing strategies.
- The expired status of the patent has facilitated the proliferation of generic versions, increasing accessibility but reducing exclusivity incentives.
- For innovators, understanding the precise scope and claims of the ‘849 patent aids in designing around existing IP and strategizing for new formulations or methods.
Frequently Asked Questions
1. What specific drugs are covered by the ‘849 patent?
While the patent broadly covers pharmaceutical compositions, it was predominantly applied to formulations containing certain antihypertensive or cardiovascular agents, though it does not specify a single active pharmaceutical ingredient. The patent’s claims focus on the formulation parameters rather than the drug itself.
2. How does the patent’s claims affect generic drug manufacturers?
During the patent’s active life, generics could not produce formulations identical to those protected by ‘849 without licensing. Post-expiration, generic manufacturers can produce similar formulations unless they infringe on later patents or specific manufacturing processes.
3. Are there notable litigations involving the ‘849 patent?
To date, no major litigations are publicly known concerning ‘849; however, its citation history suggests it was a foundational reference in subsequent pharmaceutical patent filings.
4. Can formulations developed today infringe on the ‘849 patent?
Since the patent expired in 2012, formulations introduced after that date do not infringe. However, during its enforceable period, any similarity in composition or manufacturing process could have led to infringement claims.
5. What innovations have been inspired by the ‘849 patent?
Recent patents cite ‘849 to underpin advancements in nanoparticulate drug delivery, bioavailability enhancement, and controlled-release systems, reflecting its influence on subsequent pharmaceutical technologies.
References
[1] U.S. Patent 5,681,849 (Grant Date: October 28, 1997)
[2] US Patent Classification literature, CPC A61K 9/14, 2000s.
[3] Prior art references, including US Patent 4,345,933, and literature on lipid-based drug delivery systems.
