United States Patent 5,453,425: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,453,425, titled "Risperidone oral formulation," was granted on September 26, 1995. This patent is significant in the pharmaceutical industry, particularly for the formulation and administration of the antipsychotic drug risperidone. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background of Risperidone
Risperidone is an atypical antipsychotic medication used to treat schizophrenia, bipolar disorder, and irritability associated with autism. The development of stable oral formulations of risperidone was crucial for its effective administration and patient compliance.
Scope of the Invention
The patent 5,453,425 describes a process for preparing physicochemically stable aqueous solutions of risperidone for oral administration. This invention is notable for not containing sorbitol, a common ingredient in many oral formulations that can cause gastrointestinal side effects[1].
Key Components of the Formulation
- Active Ingredient: Risperidone
- Preservative: Added to ensure the stability and safety of the solution
- Buffer Components: Acid and base components to adjust the pH of the solution
- Sweetening and Flavoring Agents: Optional additives to improve palatability
Preparation Process
The process involves several steps:
- Dissolving the preservative in heated water
- Diluting the solution with an equal amount of water
- Adding the acid component of the buffer and the active ingredient risperidone
- Stirring until complete dissolution and cooling to room temperature
- Adjusting the pH with the base component of the buffer and further diluting to the required end-volume[1].
Claims of the Patent
The claims of a patent define the boundaries of the invention and are crucial for determining the scope of protection. For US 5,453,425, the claims are specific to the process of preparing the risperidone solution and the composition itself.
Claim Drafting
Claim drafting requires a delicate balance between being too broad and too narrow. The claims in this patent are carefully crafted to cover the specific process and composition without being overly broad or too narrow, ensuring that they are enforceable and protect the invention adequately[2].
Patent Landscape
Related Patents and Applications
The patent 5,453,425 is part of a family of patents related to aqueous risperidone formulations. Other patents in this family include US 5,616,587 and US RE39,181, which also deal with various aspects of risperidone formulations[1].
Global Patent System
The patent has international counterparts, such as those filed in Taiwan, the Philippines, Turkey, and China, indicating a global strategy to protect the invention. This is common in the pharmaceutical industry where intellectual property protection is critical across multiple jurisdictions[1].
Public Access and Search Tools
The USPTO provides various tools for searching and accessing patent information, including the Global Dossier and the Patent Examination Data System (PEDS). These tools allow users to view the file histories of related applications and access citation data, which can be useful for understanding the broader patent landscape[4].
Economic and Legal Implications
Costs and Timeframe
Obtaining and maintaining a patent is a costly and time-consuming process. For a utility patent like US 5,453,425, the total costs can range from $8,000 to $20,000, and the process can take several years from initial filing to patent issuance[2].
Enforcement and Utilization
The exclusive rights granted by a patent can be used in various ways, including practicing the invention, licensing, selling the rights, or enforcing them against infringers. Effective utilization of these rights is crucial for the patent holder to derive value from the invention[2].
Industry Impact
Pharmaceutical Formulations
The development of stable oral formulations of risperidone has significantly impacted patient compliance and treatment outcomes. This patent exemplifies the importance of formulation science in the pharmaceutical industry, where small changes in formulation can have substantial effects on drug efficacy and safety.
Competitive Landscape
In the competitive landscape of pharmaceuticals, patents like US 5,453,425 play a critical role in protecting intellectual property and preventing generic competition. This allows the patent holder to recoup investment in research and development and maintain market share[2].
Key Takeaways
- Stable Aqueous Solution: The patent describes a process for preparing a physicochemically stable aqueous solution of risperidone without sorbitol.
- Claims and Scope: The claims are specific to the process and composition, ensuring adequate protection without being overly broad or narrow.
- Global Protection: The patent has international counterparts, reflecting a global strategy for intellectual property protection.
- Economic and Legal Considerations: Obtaining and maintaining the patent is costly and time-consuming, but crucial for deriving value from the invention.
- Industry Impact: The patent has significant implications for patient compliance and treatment outcomes in the pharmaceutical industry.
FAQs
What is the main invention described in US Patent 5,453,425?
The main invention is a process for preparing physicochemically stable aqueous solutions of risperidone for oral administration without sorbitol.
How is the risperidone solution prepared according to the patent?
The solution is prepared by dissolving the preservative in heated water, adding the acid component of the buffer and risperidone, adjusting the pH, and diluting to the required end-volume.
Why is the absence of sorbitol significant in this patent?
The absence of sorbitol is significant because sorbitol can cause gastrointestinal side effects, and its exclusion improves the tolerability and safety of the oral formulation.
What are the economic implications of obtaining and maintaining this patent?
Obtaining and maintaining the patent is costly, ranging from $8,000 to $20,000, and the process can take several years, but it allows the patent holder to protect their intellectual property and derive value from the invention.
How does this patent impact the pharmaceutical industry?
The patent impacts the industry by providing a stable and safe oral formulation of risperidone, improving patient compliance and treatment outcomes, and protecting the intellectual property of the patent holder.
Sources
- US5453425A - Risperidone oral formulation - Google Patents
- Basics of Patenting an Invention in the United States - Part 2 - DRM
- Patent Claims Research Dataset - USPTO
- Search for patents - USPTO
