United States Patent 5,238,944: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,238,944, titled "Topical formulations and transdermal delivery systems containing 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine," is a significant patent in the field of pharmaceutical formulations. This patent, issued to inventors who developed innovative methods for enhancing skin penetration of drugs, is crucial for understanding the landscape of transdermal drug delivery systems.
Background
The patent was granted for a pharmaceutical formulation designed for the topical or transdermal delivery of the agent 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine. This compound is used for treating various conditions, including viral infections such as Type I or Type II Herpes simplex infections[4].
Scope of the Patent
Pharmaceutical Formulations
The patent covers a range of pharmaceutical formulations, including creams, ointments, pressure-sensitive adhesive coatings, and adhesive-coated sheet materials. These formulations are designed to enhance the skin penetration of the active agent, 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine[4].
Key Components
The formulations are characterized by the use of specific fatty acids, such as isostearic acid and oleic acid, which are included in a total amount of about 3 percent to about 45 percent by weight based on the total weight of the formulation. These fatty acids are critical for enhancing the transdermal flux of the drug through intact skin[4].
Performance Metrics
The patent specifies that the formulation must provide a penetration of the agent of at least about 10% (and preferably at least about 15%) of the total amount of the agent contained in the formulation in 24 hours, as tested in the hairless mouse skin model[4].
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention. These claims cover:
- The pharmaceutical formulation itself, including the specific composition and the presence of 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine.
- The method of preparing the formulation.
- The use of the formulation for treating viral infections[4].
Dependent Claims
Dependent claims further specify the details of the formulation, such as the types of fatty acids used, the concentration of these fatty acids, and the form of the final product (e.g., creams, ointments, patches)[4].
Patent Landscape
Prior Art
The patent references several prior art patents that disclose methods and compositions for enhancing skin penetration of drugs. For example, U.S. Pat. No. 4,746,515 discloses the use of glyceryl monolaurate as a skin penetration enhancer, and U.S. Pat. No. 4,751,087 discusses the use of a combination of ethyl oleate and glyceryl monolaurate for this purpose[4].
International Context
The patent is part of a broader global landscape of intellectual property related to pharmaceutical formulations. Similar patents and applications can be found in databases such as the European Patent Office (EPO), Japan Patent Office (JPO), and the World Intellectual Property Organization (WIPO)[1].
Impact on Innovation
Patent Scope and Quality
The scope of this patent is significant in the context of debates over patent quality. Research has shown that narrower claims, such as those in this patent, are associated with a higher probability of grant and a shorter examination process. This suggests that the patent office has carefully defined the scope to ensure clarity and validity[3].
Licensing and Litigation
The specificity of the claims in this patent can reduce licensing and litigation costs by clearly defining what is protected and what is not. This clarity is crucial for innovators who need to navigate the complex landscape of intellectual property rights[3].
Practical Applications
Clinical Use
The formulations described in the patent are designed for clinical use, particularly for treating viral infections. The substantially non-irritating nature of these formulations, as tested in conventional repeat skin irritation tests, makes them suitable for patient use[4].
Manufacturing
The patent provides detailed instructions on how to prepare the formulations, which is essential for manufacturers. The use of specific fatty acids and the method of incorporating them into the formulation are critical steps that must be followed to ensure the efficacy of the final product[4].
Regulatory Considerations
FDA Guidelines
The development and approval of these formulations must comply with FDA guidelines. The patent references tests such as those described in Draize et al., which are standard for assessing skin irritation, indicating that the inventors have considered regulatory requirements[4].
Conclusion
United States Patent 5,238,944 is a comprehensive patent that covers innovative pharmaceutical formulations for transdermal drug delivery. The scope and claims of the patent are well-defined, reflecting a careful balance between protecting intellectual property and ensuring clarity and validity. This patent is a significant contribution to the field of pharmaceuticals, offering practical solutions for treating viral infections and enhancing skin penetration of drugs.
Key Takeaways
- Specific Formulations: The patent covers specific pharmaceutical formulations using 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine.
- Enhanced Skin Penetration: The formulations use fatty acids like isostearic acid and oleic acid to enhance skin penetration.
- Clinical Use: Designed for treating viral infections, including Type I or Type II Herpes simplex infections.
- Regulatory Compliance: Formulations are tested for skin irritation according to FDA guidelines.
- Patent Landscape: Part of a broader global landscape of intellectual property related to pharmaceutical formulations.
FAQs
What is the main purpose of United States Patent 5,238,944?
The main purpose of this patent is to protect innovative pharmaceutical formulations designed for the topical or transdermal delivery of the agent 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine.
What are the key components of the formulations described in the patent?
The key components include the active agent 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine and specific fatty acids such as isostearic acid and oleic acid.
How do the formulations enhance skin penetration?
The formulations enhance skin penetration by using fatty acids that increase the transdermal flux of the drug through intact skin.
What are the clinical applications of these formulations?
These formulations are designed for treating viral infections, including Type I or Type II Herpes simplex infections.
How does this patent fit into the broader patent landscape?
This patent is part of a global landscape of intellectual property related to pharmaceutical formulations, with similar patents and applications found in various international databases.
Sources
- USPTO: Search for patents - USPTO. Retrieved from https://www.uspto.gov/patents/search
- Regulations.gov: Laboratories, Inc. is the owner of US. Patent No. 4,689,338. Retrieved from https://downloads.regulations.gov/FDA-1997-E-0126-0003/attachment_1.pdf
- SSRN: Patent Claims and Patent Scope. Retrieved from https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2844964
- Google Patents: US5238944A - Topical formulations and transdermal delivery systems containing 1-isobutyl-1H-imidazo[4,5-c]quinolin-4-amine. Retrieved from https://patents.google.com/patent/US5238944A/en
- Regulations.gov: MAY - 8 1997 JUN - 4 1997. Retrieved from https://downloads.regulations.gov/FDA-1997-E-0126-0002/attachment_1.pdf
