Understanding the Scope and Claims of United States Patent 5,696,172: A Detailed Analysis
Introduction
United States Patent 5,696,172, titled "Injectable mesna solutions," is a patent that has been granted for a specific formulation of mesna, a drug used to prevent urothelial toxicity associated with the use of certain chemotherapeutic agents. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background of the Invention
Mesna, or sodium 2-mercaptoethanesulfonate, is a protective agent used to reduce the incidence of ifosfamide-induced and cyclophosphamide-induced hemorrhagic cystitis. The patent in question addresses the formulation of injectable mesna solutions, which is crucial for the effective administration of this drug.
Claims of the Patent
The patent includes several claims that define the scope of the invention. Here are the key claims:
Independent Claims
- Claim 1 typically describes the composition of the injectable mesna solution, including the presence of mesna, a preservative such as benzyl alcohol, and other components like sodium hydroxide and water for injection[4].
Dependent Claims
- Dependent claims further specify the concentrations of the components, the pH range of the solution, and other specific characteristics of the formulation. For example, Claim 2 might specify the concentration of benzyl alcohol, while Claim 3 could detail the pH range of the solution[4].
Scope of the Invention
The scope of the invention is defined by the claims and the description provided in the patent specification. Here are some key aspects:
Composition
- The patent describes an injectable solution containing mesna, which is stabilized by the presence of benzyl alcohol as a preservative. The formulation also includes sodium hydroxide to adjust the pH and water for injection as a solvent[4].
Preservative Role
- Benzyl alcohol is included due to its preservative properties, although it can oxidize to benzaldehyde over time. This aspect is critical for ensuring the stability and safety of the injectable solution[4].
pH Adjustment
- The solution's pH is adjusted using sodium hydroxide to ensure it is within a range that is compatible with intravenous administration.
Patent Landscape
Related Patents
- The patent landscape for injectable mesna solutions includes other patents related to formulations, delivery methods, and stabilizers. For instance, other patents might focus on different preservatives or additional components to enhance stability or efficacy.
Prior Art
- The patentability of the invention was determined by comparing it against prior art in the field. The patent office would have evaluated whether the specific formulation and claims presented were novel and non-obvious over existing solutions.
Impact on Pharmaceutical Industry
Clinical Use
- The formulation described in this patent has significant clinical implications. It ensures that mesna can be effectively administered to patients undergoing chemotherapy, reducing the risk of hemorrhagic cystitis.
Manufacturing and Quality Control
- The patent's specifications on the composition and pH range provide clear guidelines for manufacturers to ensure the quality and consistency of the injectable mesna solutions.
Legal and Regulatory Considerations
Patent Validity
- The validity of the patent can be challenged based on obviousness or novelty. Recent changes in patent law, such as the Federal Circuit's decision in LKQ Corp. v. GM Global Tech Operations LLC, emphasize the need for a flexible approach to obviousness, which could impact how future challenges to this patent are evaluated[1].
Infringement and Litigation
- Any potential infringement of this patent would need to be assessed based on the claims and the specific formulation described. Litigation would involve determining whether another product infringes on the patented composition and method of preparation.
Key Takeaways
- Composition and Claims: The patent specifies a unique formulation of mesna with benzyl alcohol as a preservative and sodium hydroxide for pH adjustment.
- Clinical Significance: The invention is crucial for the safe and effective administration of mesna in clinical settings.
- Patent Landscape: The patent is part of a broader landscape of pharmaceutical formulations, with ongoing developments in preservatives and delivery methods.
- Legal Considerations: The patent's validity and potential infringement would be evaluated under current patent laws, including recent changes in obviousness tests.
FAQs
What is the main purpose of the patent US 5,696,172?
The main purpose of the patent is to describe a specific formulation of an injectable mesna solution, which is used to prevent urothelial toxicity associated with certain chemotherapeutic agents.
What are the key components of the injectable mesna solution described in the patent?
The key components include mesna, benzyl alcohol as a preservative, sodium hydroxide for pH adjustment, and water for injection.
How does the recent Federal Circuit decision on design patent obviousness affect pharmaceutical patents like US 5,696,172?
The decision primarily affects design patents, but the emphasis on a flexible approach to obviousness could have broader implications for how obviousness is evaluated in utility patents, including pharmaceutical formulations.
What are the clinical implications of this patent?
The patent ensures that mesna can be effectively and safely administered to patients undergoing chemotherapy, reducing the risk of hemorrhagic cystitis.
How is the stability of the injectable mesna solution ensured?
The stability is ensured through the use of benzyl alcohol as a preservative, although it can oxidize to benzaldehyde over time.
Sources
- Full Federal Circuit Eliminates “Improperly Rigid” Tests for Design Patent Obviousness. Ballard Spahr.
- Provisur - United States Court of Appeals for the Federal Circuit. United States Court of Appeals for the Federal Circuit.
- Patent Claims Research Dataset. USPTO.
- US5696172A - Injectable mesna solutions. Google Patents.
- Do Your Patents Claim Engagement of Components as Intended?. Crowell.
