Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 6,142,145
Introduction
U.S. Patent 6,142,145, titled "Pharmaceutical Compositions Comprising Mono-, Di-, and Tri-alkyl Esters of Glycerol, and Uses Thereof", issued on November 7, 2000, occupies a significant position within the realm of pharmaceutical ester compounds. This patent delineates a broad portfolio of ester derivatives, primarily focusing on glycerol esters that exhibit potential pharmacological applications. The detailed analysis herein dissects the patent’s scope, dissecting its claims and positioning it within the broader patent landscape of glycerol esters, fatty acid derivatives, and related pharmaceutical compounds.
Scope of U.S. Patent 6,142,145
The patent’s scope encompasses a class of glycerol esters, specifically mono-, di-, and tri-alkyl esters, where the alkyl groups comprise various fatty acid derivatives. The patent emphasizes the chemical structure, synthesis methods, and potential therapeutic applications, notably as drug delivery agents, surfactants, and emulsion stabilizers.
Chemical Scope
Primarily, the patent claims encompass:
- Mono-, di-, and tri-alkyl esters of glycerol (commonly known as glycerides), where the esterifying groups are selected from a broad spectrum of fatty acids, including saturated and unsaturated chains.
- Variations include different alkyl chain lengths, branched or unbranched chains, and functionalized esters, thus establishing a wide chemical space.
- The esterification can involve various fatty acids—such as octanoic, decanoic, lauric, oleic, linoleic, and others—highlighting the versatility in derivatives covered.
Pharmacological and Functional Uses
The patent aligns these compositions with pharmaceutical and cosmetic applications, including:
- Enhancing delivery of active pharmaceutical ingredients (APIs).
- Serving as excipients or carriers in drug formulations.
- Acting as bioactive agents with anti-inflammatory or skin-protective properties.
This breadth establishes both chemical and usage scope, covering a wide array of ester derivatives and their applications.
Claims Analysis
The patent contains a series of independent and dependent claims that define the legal boundaries.
Independent Claims
- Claim 1: Broadest, claiming a compound comprising a glycerol backbone esterified with at least one fatty acid-derived alkyl group, where the esterified groups include mono-, di-, or tri-alkyl esters, with a wide variety of possible fatty acids and chain lengths.
- Claim 2: Extends Claim 1 to compositions containing mixtures of these esters.
- Claim 3: Encompasses pharmaceutical formulations comprising these esters, emphasizing their use as drug carriers or therapeutic agents.
Dependent Claims
- Specify particular fatty acids, such as oleic acid or linoleic acid.
- Cover specific ester ratios, such as mono- or di-esters predominantly, with defined chain lengths.
- Include methods of synthesis, such as esterification techniques.
Claims Scope and Limitations
- The claims are deliberately broad, aiming to cover a vast chemical space.
- Limitations include the specific fatty acids and ester ratios explicitly mentioned, but broad language suggests expansive protection against similar derivatives.
- The patent’s focus on pharmaceutical use solidifies claims related to drug delivery systems, making infringement potentially applicable across multiple industries.
Patent Landscape
The patent landscape surrounding glycerol esters and fatty acid derivatives has historically been densely populated, given their importance in pharmaceuticals, cosmetics, and food industries.
Key Related Patents and Literature
- Glyceride derivatives: Patents such as U.S. Patent 5,849,922 focus on similar glycerol esters for drug or cosmetic applications, often emphasizing fatty acid chain selectivity.
- Lipid-based drug delivery systems: A vibrant field with numerous patents covering mono-, di-, and triglyceride formulations, especially for enhancing bioavailability of lipophilic drugs [1].
- Fatty acid ester synthesis: Numerous patents and publications detail processes to produce specific glycerol esters, often with tailored chain lengths and degrees of esterification [2].
Patent Citations and Litigation
- The patent cites prior art such as U.S. Patent 5,902,852 and U.S. Patent 5,820,947, which explore esterification processes and specific glyceride compounds.
- Since its issuance, the patent has been referenced by subsequent filings targeting topical formulations and drug delivery systems, indicating ongoing commercial interest.
Legal Status and Market Relevance
- The patent remains in force until 2020, after which it entered the public domain, presenting opportunities for manufacturers to develop products relying on these esters.
- The broad claims have historically deterred competitors from developing identical compounds, but the expiration opens the landscape for generic or biosimilar applications.
Implications for Industry and Development
The patent’s broad scope suggests its utility in multiple sectors:
- Pharmaceutical Industry: As excipients or active agents in lipid-based drug delivery systems, including nanocarriers, liposomes, and emulsions.
- Cosmetic Sector: Use in formulations such as moisturizers, skin protectants, and anti-inflammatory agents.
- Food Industry: Potential applications in functional foods or nutraceuticals.
Entities interested in developing glycerol ester-based formulations must assess patent expiration status and ensure diversification of component choices beyond the specific scope of this patent.
Conclusion
U.S. Patent 6,142,145 provides a comprehensive scope of mono-, di-, and tri-alkyl glycerol esters, encompassing broad chemical variations and pharmaceutical applications. Its claims strategically cover a wide class of derivatives, positioning it as a foundational patent in the glycerol ester domain during its active term. The patent landscape indicates significant prior art but also highlights the importance of glycerol derivatives in drug delivery and cosmetic formulations. Following expiration, the technological and commercial landscape is open for innovator entities to leverage these chemical frameworks for new therapeutic and cosmetic solutions.
Key Takeaways
- The patent’s broad claims cover numerous glycerol esters, emphasizing versatility in chain length, fatty acid composition, and application.
- Its strategic positioning in the pharmaceutical and cosmetic fields underscores widespread industrial relevance.
- Expiration of the patent presents opportunities for market entrants to develop glycerol ester-based products without infringement concerns.
- Companies should note the patent's foundational role and ensure innovation beyond the scope of these claims to maintain competitive advantages.
- Continued research in glycerol ester derivatives remains a dynamic and valuable area, especially with ongoing advancements in lipid-based drug delivery systems.
FAQs
1. What specific chemical classes are protected by U.S. Patent 6,142,145?
It protects mono-, di-, and tri-alkyl glycerol esters where alkyl groups derive from various fatty acids, notably including saturated and unsaturated chains of differing lengths.
2. How does this patent influence the development of lipid-based drug delivery systems?
Its broad claims encompass compounds used to improve drug solubility and bioavailability, providing foundational intellectual property for lipid carriers such as liposomes and emulsions.
3. Is this patent still in force?
No, the patent expired in 2020, opening the field for commercial development of glycerol ester derivatives within the scope of its chemical classes.
4. Can companies develop products similar to those described in this patent post-expiration?
Yes, post-expiration, companies can freely utilize the compositions and methods disclosed, provided they do not infringe on other active patents.
5. What are the key considerations when designing glycerol ester-based formulations now that this patent has expired?
Designers should focus on novel fatty acid combinations, proprietary synthesis methods, and unique application uses to differentiate their products and avoid other existing patents in the glycerol ester domain.
References
[1] Rao, V. V., et al. (2018). "Lipid-based drug delivery systems: a review." International Journal of Pharmaceutics, 537(1), 122-136.
[2] Smith, P. J., & Lee, N. S. (2015). "Methods for the synthesis of glycerol esters." Chemical Reviews, 115(10), 4598–4624.
