United States Patent 5,134,127: A Detailed Analysis of Scope and Claims
Introduction
United States Patent 5,134,127, titled "Derivatives of cyclodextrins exhibiting enhanced aqueous solubility and the use thereof," is a significant patent in the field of pharmaceuticals, particularly in the development of solubilizing agents for water-insoluble drugs. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background
Cyclodextrins are cyclic oligosaccharides known for their ability to form inclusion complexes with a variety of guest molecules, enhancing the solubility and stability of these molecules. The patent in question focuses on derivatives of cyclodextrins that exhibit enhanced aqueous solubility, making them highly useful in pharmaceutical formulations.
Scope of the Patent
The patent covers the preparation and use of sulfoalkyl ether cyclodextrin derivatives. These derivatives are designed to improve the aqueous solubility of water-insoluble drugs, making them suitable for oral, intranasal, or parenteral administration.
Key Components
- Cyclodextrin Derivatives: The patent describes the synthesis of sulfoalkyl ether derivatives of cyclodextrins. These derivatives are modified to include sulfoalkyl groups, which enhance their aqueous solubility[4].
- Solubilizing Agents: The primary application of these derivatives is as solubilizing agents for drugs that are otherwise poorly soluble in water. This is crucial for developing effective pharmaceutical formulations.
- Administration Routes: The patent specifies that these derivatives can be used for various administration routes, including oral, intranasal, and parenteral (injectable) formulations.
Claims of the Patent
The patent includes several claims that define the scope of the invention:
Composition Claims
- The patent claims compositions comprising sulfoalkyl ether cyclodextrin derivatives and water-insoluble drugs. These compositions are designed to maintain the drug in solution at therapeutically effective concentrations[4].
Method Claims
- Claims also cover methods for preparing these cyclodextrin derivatives and their use in pharmaceutical formulations. This includes processes for synthesizing the sulfoalkyl ether groups and incorporating them into cyclodextrin molecules[4].
Use Claims
- The patent claims the use of these derivatives as solubilizing agents for various drugs, highlighting their application in enhancing the solubility and bioavailability of water-insoluble pharmaceuticals[4].
Patent Landscape
Related Patents
- Other patents, such as US Patent 9,629,797, also deal with cyclodextrin inclusion complexes, but they are specific to different drugs and formulations. For example, US Patent 9,629,797 covers a carbamazepine-cyclodextrin inclusion complex for parenteral administration[1].
- US Patent 9,023,790B2 discusses posaconazole intravenous solution formulations stabilized by substituted β-cyclodextrin, another example of cyclodextrin derivatives in pharmaceutical use[5].
International Protection
- The patent landscape for cyclodextrin derivatives extends beyond the United States. Patents like the one described in the Canadian Patents Database (CA 2477049) cover ophthalmic antibiotic drug formulations containing cyclodextrin compounds, indicating a global interest in these technologies[2].
Legal and Regulatory Aspects
- The patent has expired, as indicated by its legal status. This means that the technology described is now in the public domain and can be freely used without infringing on the original patent[4].
Impact on Pharmaceutical Development
- The development of sulfoalkyl ether cyclodextrin derivatives has significantly impacted the pharmaceutical industry by enabling the formulation of drugs that were previously difficult to solubilize. This has improved the bioavailability and efficacy of many medications.
- Enhanced Solubility: The use of these derivatives has allowed for the creation of stable and effective pharmaceutical solutions, which is critical for ensuring consistent drug delivery and therapeutic outcomes.
- Broader Applications: Beyond the specific drugs mentioned, the technology has broader applications in the formulation of various pharmaceuticals, making it a versatile tool in drug development.
Key Takeaways
- Cyclodextrin Derivatives: The patent focuses on sulfoalkyl ether cyclodextrin derivatives that enhance aqueous solubility.
- Pharmaceutical Applications: These derivatives are used as solubilizing agents for water-insoluble drugs in oral, intranasal, and parenteral formulations.
- Expired Patent: The patent has expired, making the technology publicly available.
- Global Relevance: Similar technologies are protected by patents in other countries, highlighting the global importance of cyclodextrin derivatives in pharmaceuticals.
FAQs
What is the primary use of the sulfoalkyl ether cyclodextrin derivatives described in US Patent 5,134,127?
The primary use is as solubilizing agents for water-insoluble drugs to enhance their aqueous solubility and bioavailability.
Which administration routes are covered by the patent?
The patent covers oral, intranasal, and parenteral (injectable) administration routes.
Is the patent still active?
No, the patent has expired and is no longer active.
How do sulfoalkyl ether cyclodextrin derivatives improve drug solubility?
These derivatives enhance aqueous solubility by incorporating sulfoalkyl groups into the cyclodextrin molecules, allowing them to form stable inclusion complexes with water-insoluble drugs.
Are there similar patents in other countries?
Yes, similar patents exist in other countries, such as Canada and Australia, covering various applications of cyclodextrin derivatives in pharmaceuticals.
Sources
- Drug Patent Watch: Parenteral carbamazepine formulation.
- Canadian Patents Database: Ophthalmic antibiotic drug formulations containing a cyclodextrin compound and cetylpyridinium chloride.
- Touro Law Review: Mastering Patent Claim Construction.
- Google Patents: Derivatives of cyclodextrins exhibiting enhanced aqueous solubility and the use thereof.
- Google Patents: Posaconazole intravenous solution formulations stabilized by substituted β-cyclodextrin.
