United States Patent 6,369,062: A Detailed Analysis of Scope and Claims
Introduction
The United States Patent 6,369,062, titled "Sustained release ranolazine formulations," is a significant patent in the pharmaceutical industry, particularly for the drug Ranexa (ranolazine). This patent, now expired, was crucial for the exclusive manufacture and distribution of Ranexa by its owner, Gilead Sciences, Inc. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this patent.
Background of Ranolazine
Ranolazine is a medication used primarily for the treatment of chronic angina. It works by inhibiting the late sodium current in cardiac cells, which helps in reducing the frequency of angina attacks without significantly affecting blood pressure or heart rate[4].
Patent Overview
Title and Publication Details
- Title: Sustained release ranolazine formulations
- Publication Number: US6369062B1
- Publication Date: May 9, 2002
- Prior Art Date: October 25, 1999
- Legal Status: Expired[4].
Scope of the Patent
The patent focuses on the formulation and method of preparing sustained release compositions of ranolazine. The scope includes:
Formulation Composition
The patent describes a sustained release formulation that contains an intimate mixture of ranolazine and a partially neutralized pH-dependent binder. This formulation is designed to release the drug over an extended period, ensuring a steady plasma concentration of ranolazine[4].
pH-Dependent Binder
The use of a pH-dependent binder is critical as it allows the formulation to release the drug in a controlled manner, depending on the pH of the gastrointestinal tract. This ensures optimal absorption and minimizes side effects[4].
Claims of the Patent
The patent includes several claims that define the scope of the invention:
Independent Claims
- Claim 1: A sustained release pharmaceutical formulation comprising ranolazine and a partially neutralized pH-dependent binder.
- Claim 2: The formulation of claim 1, where the pH-dependent binder is selected from the group consisting of hydroxypropyl methylcellulose, hydroxypropyl cellulose, and polyvinyl acetate phthalate.
- Claim 3: The formulation of claim 1, where the ranolazine is present in an amount of about 50% to about 90% by weight of the formulation[4].
Dependent Claims
The dependent claims further specify the details of the formulation, including the ratio of ranolazine to the binder, the method of preparation, and the dosage forms (e.g., tablets, capsules).
Patent Landscape
Related Patents
The patent 6,369,062 is part of a larger family of patents related to ranolazine formulations. Other notable patents include:
- US6503911: Another sustained release formulation patent with similar claims.
- US6525057: Focuses on different aspects of sustained release formulations.
- US6620814: Also deals with sustained release formulations, highlighting variations in the binder and preparation methods[2].
Patent Expiry and Generic Launch
All the key patents related to ranolazine, including US6369062, expired in May 2019. This expiry allowed for the launch of generic versions of Ranexa, marking a significant shift in the market dynamics[2].
Impact on Market and Generic Entry
The expiry of these patents opened the market for generic manufacturers. Companies seeking to launch generic versions of Ranexa could do so by filing Abbreviated New Drug Applications (ANDAs) with the FDA, potentially including paragraph IV certifications to challenge the validity or enforceability of the original patents[2].
Legal Activities and Patent Litigation
Several legal activities and litigations were associated with these patents, including post-issue communications and correspondence address changes. These activities were crucial in determining the final expiry dates and the potential for generic entry[2].
Metrics for Patent Scope
The scope of patents like US6369062 can be analyzed using metrics such as independent claim length and independent claim count. These metrics help in understanding the breadth and clarity of the patent claims, which are critical for patent quality and the potential for litigation[3].
Conclusion
The United States Patent 6,369,062 played a pivotal role in the exclusive production and distribution of Ranexa. Understanding its scope, claims, and the broader patent landscape is essential for both pharmaceutical companies and generic manufacturers. The expiry of this patent has significantly impacted the market, allowing for the entry of generic versions and changing the competitive landscape.
Key Takeaways
- Patent Scope: The patent covers sustained release formulations of ranolazine with a pH-dependent binder.
- Claims: Include independent and dependent claims specifying the formulation composition and preparation methods.
- Patent Expiry: The patent expired in May 2019, allowing for generic entry.
- Market Impact: The expiry has opened the market for generic versions of Ranexa.
- Legal Activities: Various legal activities influenced the final expiry dates and generic launch.
FAQs
What is the primary use of the drug ranolazine?
Ranolazine is primarily used for the treatment of chronic angina.
What is the significance of the pH-dependent binder in the patent?
The pH-dependent binder ensures the controlled release of ranolazine in the gastrointestinal tract, optimizing absorption and minimizing side effects.
When did the key patents related to ranolazine expire?
The key patents related to ranolazine expired in May 2019.
How can generic manufacturers launch a generic version of Ranexa before the patent expiry?
Generic manufacturers can seek FDA approval by filing an ANDA with a paragraph IV certification, challenging the validity or enforceability of the original patents.
What metrics can be used to analyze the scope of a patent?
Metrics such as independent claim length and independent claim count can be used to analyze the scope and clarity of patent claims.
Cited Sources:
- US20140221286A1 - Sodium Channel Blockers Reduce Glucagon Secretion
- Pharsight - Ranexa patent expiration
- Hoover Institution - Patent Claims and Patent Scope
- Google Patents - US6369062B1 - Sustained release ranolazine formulations
- Google Patents - US20120177729A1 - Sustained release composition of ranolazine
