United States Patent 8,252,332: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 8,252,332, titled "Gastric retained gabapentin dosage form," is a significant patent in the pharmaceutical industry, particularly in the field of epilepsy and postherpetic neuralgia treatment. This patent, held by Depomed, Inc., pertains to a novel dosage form of gabapentin designed to be retained in the stomach, ensuring a controlled release of the medication.
Background
Gabapentin is a widely used medication for treating epilepsy, postherpetic neuralgia, and other neurological conditions. The traditional immediate-release formulations of gabapentin often require multiple daily doses, which can lead to fluctuations in plasma concentrations and reduced patient compliance. The invention described in US Patent 8,252,332 addresses these issues by providing a gastric retained dosage form that allows for once- or twice-daily administration.
Scope of the Patent
Dosage Form Design
The patent describes a dosage form that incorporates a matrix designed to swell in the presence of gastric fluid, thereby retaining the dosage form in the stomach for an extended period. This swelling mechanism ensures that the gabapentin is released slowly and consistently, maintaining therapeutic plasma concentrations over a longer duration[2].
Clinical Benefits
The gastric retained dosage form offers several clinical benefits, including improved patient compliance due to reduced dosing frequency, more stable plasma concentrations, and potentially fewer side effects associated with peak and trough levels of the medication.
Claims of the Patent
Key Claims
The patent includes several key claims that define the scope of the invention:
- Claim 1: A dosage form comprising a matrix that swells in the presence of gastric fluid, retaining the dosage form in the stomach and releasing gabapentin over an extended period.
- Claim 2: The dosage form of claim 1, where the matrix is designed to release gabapentin at a rate that maintains therapeutic plasma concentrations for at least 12 hours.
- Claim 3: A method of treating a disease state, such as epilepsy or postherpetic neuralgia, by administering the dosage form of claim 1 once or twice daily[1].
Dependent Claims
The patent also includes several dependent claims that further specify the composition and functionality of the dosage form. These claims detail the materials used in the matrix, the size and shape of the dosage form, and the specific release profiles of gabapentin.
Patent Landscape
Related Patents
The US Patent 8,252,332 is part of a broader portfolio of patents held by Depomed, Inc., related to gabapentin formulations. Other relevant patents include:
- US Patent 6,635,280: Describes a similar gastric retained dosage form but with different matrix compositions.
- US Patent 6,488,962: Focuses on the method of manufacturing these dosage forms.
- US Patent 7,438,927: Covers additional aspects of the dosage form's design and functionality[2].
Litigation and Enforcement
Depomed, Inc. has been involved in several legal battles to protect the intellectual property rights associated with these patents. For example, in the case of Depomed, Inc. v. Actavis Elizabeth LLC, the court found that the generic versions of gabapentin produced by Actavis infringed upon Depomed's patents, including the '332 patent. The court ruled that Actavis knowingly and intentionally induced infringement by marketing their generic product for the same indications as Depomed's branded product, Gralise[2][5].
Impact on the Pharmaceutical Industry
Market Protection
The patent provides significant market protection for Depomed's branded product, Gralise, by preventing generic manufacturers from producing similar gastric retained gabapentin formulations until the patent expires.
Innovation
The invention described in the patent has driven innovation in the field of controlled-release formulations. It has set a precedent for developing other medications with similar delivery mechanisms, enhancing patient compliance and therapeutic outcomes.
Key Takeaways
- Gastric Retention Mechanism: The patent describes a novel dosage form that swells in the stomach, ensuring extended release of gabapentin.
- Clinical Benefits: Improved patient compliance, stable plasma concentrations, and reduced side effects.
- Claims and Scope: Key claims define the dosage form, its composition, and the method of treatment.
- Related Patents: Part of a broader portfolio of patents related to gabapentin formulations.
- Litigation: Depomed has successfully defended its patents against generic manufacturers.
FAQs
What is the primary innovation of US Patent 8,252,332?
The primary innovation is a gastric retained dosage form of gabapentin that swells in the presence of gastric fluid, allowing for once- or twice-daily administration.
How does the dosage form improve patient compliance?
By reducing the frequency of dosing, the gastric retained dosage form improves patient compliance and maintains therapeutic plasma concentrations over a longer period.
What are the key claims of the patent?
The key claims include the design of the dosage form, its composition, and the method of treating disease states such as epilepsy or postherpetic neuralgia.
Has Depomed, Inc. been involved in any litigation related to this patent?
Yes, Depomed has been involved in several legal battles, including Depomed, Inc. v. Actavis Elizabeth LLC, to protect its intellectual property rights.
What is the impact of this patent on the pharmaceutical industry?
The patent provides market protection for Depomed's branded product and has driven innovation in controlled-release formulations, enhancing patient compliance and therapeutic outcomes.
Sources
- US Patent 8,252,332 - Gastric retained gabapentin dosage form
- Depomed, Inc. v. Actavis Elizabeth LLC - Robins Kaplan LLP
- Patent Analytics - Intellectual Property Law
- USPTO Patent Search
- Leda Dunn Wettre ROBINSON, WETTRE & MILLER LLC - Insight.RPXCorp.com
