United States Patent 6,958,337: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 6,958,337, titled "Crystalline antifungal polymorph," is a significant patent in the field of pharmaceuticals, particularly focusing on the antifungal agent posaconazole. This patent, granted to the assignee, is crucial for understanding the development, formulation, and application of posaconazole in various medical contexts.
Background of the Invention
Posaconazole, a triazole antifungal agent, is known for its efficacy in treating fungal infections. The patent builds upon earlier disclosures of posaconazole, such as those in WO 95/17407 and WO 96/38443, which described the compound and its use but did not provide stable crystalline forms[5].
Scope of the Patent
The patent primarily deals with the most stable crystalline polymorph Form I of posaconazole. Here are the key aspects of its scope:
Crystalline Polymorph
The patent describes the crystalline polymorph Form I of posaconazole, represented by the formula I. This specific form is highlighted for its stability and distinct physical properties, including melting point, XRPD spectrum, and IR-spectrum[1].
Pharmaceutical Compositions
The patent outlines methods for preparing pharmaceutical compositions containing the crystalline polymorph Form I of posaconazole. These compositions are designed for administration to mammals and are subject to exacting health registration standards[1].
Stability and Physical Properties
The crystalline form of posaconazole described in the patent exhibits specific physical properties that make it more stable and suitable for pharmaceutical use. This includes a defined melting point, solubility profile, and spectral characteristics[1].
Claims of the Patent
The claims of the patent are comprehensive and cover several aspects:
Composition Claims
The patent claims cover the crystalline polymorph Form I of posaconazole itself, as well as pharmaceutical compositions that include this form. These compositions can be formulated for various routes of administration[1].
Process Claims
The patent includes claims related to the processes for preparing the crystalline polymorph Form I. This involves specific steps and conditions to ensure the formation of the stable crystalline form[1].
Use Claims
The patent also claims the use of the crystalline polymorph Form I of posaconazole for treating fungal infections. This includes various therapeutic applications where posaconazole is effective[1].
Patent Landscape
The patent landscape surrounding US 6,958,337 is complex and involves several related patents and applications:
Related Patents
Other patents, such as EP 3,391,890 A1 and CA 2802929, also deal with posaconazole formulations, particularly focusing on intravenous solutions stabilized by substituted beta-cyclodextrin. These patents complement the scope of US 6,958,337 by providing additional formulation options for posaconazole[2][4].
International Applications
The patent has international implications, with corresponding applications filed under the Patent Cooperation Treaty (PCT). For example, the European Patent Specification EP 2,318,396 B1 also covers crystalline forms of posaconazole, highlighting the global relevance of this invention[5].
Assignee and Ownership
The patent is assigned to Merck Sharp & Dohme Corp., a major pharmaceutical company. The ownership history indicates that the patent has been maintained by this company, ensuring continuous development and protection of the intellectual property[4].
Clinical and Therapeutic Implications
The stable crystalline form of posaconazole described in the patent has significant clinical implications:
Stability and Efficacy
The stable crystalline form ensures consistent efficacy and stability, which are critical for antifungal treatments. This form can be more reliably formulated into various pharmaceutical products, such as oral suspensions, intravenous solutions, and other dosage forms[1][2].
Patient Compliance
The availability of stable and effective formulations of posaconazole enhances patient compliance. For instance, the intravenous solutions stabilized by substituted beta-cyclodextrin can be particularly useful in clinical settings where oral administration is not feasible[2].
Economic and Market Impact
The patent has a substantial economic and market impact:
Market Dominance
Merck Sharp & Dohme Corp., with its strong patent portfolio including US 6,958,337, maintains a significant market position in the antifungal drug market. The patent protection allows the company to exclusively market and distribute posaconazole formulations, such as NOXAFIL®, which is a branded product under this patent[5].
Research and Development
The patent encourages further research and development in the field of antifungal therapies. Other companies and researchers may build upon this invention, leading to the development of new formulations and therapeutic applications[5].
Expiration and Legal Status
The patent has expired, as indicated by its legal status. This means that the exclusive rights to the invention are no longer in effect, and the technology is now in the public domain. However, this does not diminish the significance of the patent in the historical context of pharmaceutical development[1].
Key Takeaways
- Stable Crystalline Form: The patent describes the most stable crystalline polymorph Form I of posaconazole.
- Pharmaceutical Compositions: It outlines methods for preparing pharmaceutical compositions containing this form.
- Clinical Implications: The stable form ensures consistent efficacy and stability, enhancing patient compliance.
- Market Impact: The patent has contributed to Merck Sharp & Dohme Corp.'s market dominance in antifungal treatments.
- Research and Development: The patent has encouraged further research in antifungal therapies.
FAQs
What is the main subject of United States Patent 6,958,337?
The main subject is the crystalline antifungal polymorph Form I of posaconazole.
Who is the assignee of this patent?
The assignee is Merck Sharp & Dohme Corp.
What are the key physical properties of the crystalline form described in the patent?
The key physical properties include a defined melting point, XRPD spectrum, IR-spectrum, and solubility profile.
How does the patent impact clinical practice?
The stable crystalline form ensures consistent efficacy and stability, enhancing patient compliance and treatment outcomes.
Is the patent still in effect?
No, the patent has expired, and the technology is now in the public domain.
What other patents are related to this invention?
Related patents include EP 3,391,890 A1 and CA 2802929, which deal with intravenous solutions and other formulations of posaconazole.
Sources
- US6958337B2 - Crystalline antifungal polymorph - Google Patents
- POSACONAZOLE INTRAVENOUS SOLUTION FORMULATIONS - European Patent Application
- Details for Patent: 6500867 - DrugPatentWatch
- Patent 2802929 Summary - Canadian Patents Database
- A CRYSTALLINE FORM OF POSACONAZOLE - European Patent Specification
