United States Patent 7,456,160: A Detailed Analysis of Scope and Claims
Introduction
The United States Patent 7,456,160, titled "Formulation," is a significant patent in the pharmaceutical field, particularly concerning the formulation of fulvestrant, a medication used in the treatment of hormone receptor-positive metastatic breast cancer. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background of Fulvestrant
Fulvestrant, marketed under the brand name FASLODEX, is an estrogen receptor antagonist that is administered via injection. It is crucial for the treatment of hormone receptor-positive metastatic breast cancer in postmenopausal women[2][5].
Patent Overview
Publication Details
- Publication Number: US7456160B2
- Authority: United States
- Prior Art Date: The patent builds upon earlier inventions and prior art related to pharmaceutical formulations, particularly those involving fulvestrant[1].
Scope of the Patent
Formulation Composition
The patent describes a novel sustained release pharmaceutical formulation adapted for administration by injection. This formulation contains fulvestrant, a compound known for its efficacy in treating breast cancer. The formulation is designed to enhance the solubility and stability of fulvestrant, which is otherwise poorly soluble in aqueous solutions[1].
Key Components
- Fulvestrant: The active ingredient, which is a selective estrogen receptor degrader (SERD).
- Non-Aqueous Ester Solvents: The patent specifies the use of non-aqueous ester solvents such as benzyl benzoate, ethyl oleate, isopropyl myristate, and isopropyl palmitate. Benzyl benzoate is particularly preferred at a concentration of 15% w/v[2].
- Castor Oil and Alcohol: The formulation often includes castor oil and an alcohol, such as benzyl alcohol, to facilitate the solubilization of fulvestrant[1][2].
Solubilization and Stability
The invention highlights the introduction of a non-aqueous ester solvent that is miscible in castor oil, which surprisingly eases the solubilization of fulvestrant to concentrations of at least 50 mg/mL. This approach improves the stability of the formulation by reducing the formation of oxidative degradation products[2].
Claims of the Patent
Primary Claims
The patent includes several claims that define the scope of the invention:
- Claim 1: A pharmaceutical formulation comprising fulvestrant, a non-aqueous ester solvent, and a castor oil vehicle.
- Claim 2: The formulation of claim 1, where the non-aqueous ester solvent is benzyl benzoate.
- Claim 3: The formulation of claim 1, further comprising an alcohol, such as benzyl alcohol[1].
Dependent Claims
Dependent claims further specify the concentrations and ratios of the components:
- Claim 4: The formulation of claim 1, where the concentration of fulvestrant is at least 50 mg/mL.
- Claim 5: The formulation of claim 1, where the ratio of fulvestrant to benzyl benzoate is between 1:1 to 1:10 by weight[1].
Patent Landscape
Related Patents
Several other patents are closely related to US7456160B2, including:
- U.S. Pat. No. 6,774,122: Discloses similar formulations using non-aqueous ester solvents.
- U.S. Pat. No. 8,329,680: Focuses on formulations that are substantially free of castor oil and castor oil derivatives.
- U.S. Pat. No. 8,466,139: Involves the use of ricinoleate vehicles and antioxidants to improve stability[2].
Litigation and Enforcement
The patent has been involved in litigation, particularly concerning generic versions of fulvestrant. For instance, the use of FASLODEX (fulvestrant) intramuscular injection is covered by claims of this and other related patents, leading to legal disputes over generic drug manufacturing and distribution[5].
Impact on Pharmaceutical Formulations
Enhanced Solubility and Stability
The formulation described in US7456160B2 has significantly improved the solubility and stability of fulvestrant, making it more effective and easier to administer. This innovation has set a standard for future formulations involving poorly soluble compounds[1][2].
Clinical Implications
The improved formulation has direct clinical implications, including better patient compliance and outcomes. The sustained release nature of the formulation ensures a consistent therapeutic effect over a longer period, which is crucial for the management of chronic conditions like breast cancer[2].
Key Takeaways
- Novel Formulation: The patent introduces a novel sustained release formulation for fulvestrant.
- Enhanced Solubility: The use of non-aqueous ester solvents and castor oil improves the solubility of fulvestrant.
- Stability: The formulation reduces oxidative degradation products, enhancing stability.
- Clinical Impact: The improved formulation has significant clinical implications, including better patient compliance and outcomes.
- Patent Landscape: The patent is part of a broader landscape involving related patents and litigation over generic versions.
FAQs
What is the main active ingredient in the formulation described in US7456160B2?
The main active ingredient is fulvestrant, a selective estrogen receptor degrader (SERD).
What are the key components of the formulation?
The key components include fulvestrant, non-aqueous ester solvents (such as benzyl benzoate), castor oil, and an alcohol (such as benzyl alcohol).
How does the formulation improve the solubility of fulvestrant?
The introduction of a non-aqueous ester solvent that is miscible in castor oil significantly improves the solubility of fulvestrant.
What are the clinical implications of this formulation?
The formulation ensures a consistent therapeutic effect over a longer period, improving patient compliance and outcomes in the treatment of breast cancer.
Is this patent involved in any litigation?
Yes, the patent has been involved in litigation concerning generic versions of fulvestrant and the enforcement of its claims.
Sources
- US7456160B2 - Formulation - Google Patents
- US10188663B2 - Fulvestrant formulations - Google Patents
- Patent Analytics | Intellectual Property Law
- United States Patent - googleapis.com
- in the united states district court - RPX Insight
