United States Patent 4,535,186: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 4,535,186, titled "2-Phenyl-2-(1-hydroxycycloalkyl or 1-hydroxycycloalk-2-enyl)ethylamine derivatives," is a significant patent in the field of pharmaceuticals, particularly for antidepressant medications. This patent, granted in 1985, describes a class of compounds that have been pivotal in the development of treatments for depression and anxiety.
Background of the Invention
The patent was filed by American Cyanamid Company and granted on August 13, 1985. It pertains to a group of hydroxycycloalkanephenethyl amine derivatives, which are identified as useful antidepressants. One of the key compounds described in this patent is Venlafaxine, a serotonin and norepinephrine reuptake inhibitor (SNRI) that has become a widely used medication for treating depression and anxiety disorders[4].
Scope of the Patent
Chemical Structure and Derivatives
The patent outlines the structural formula for the hydroxycycloalkanephenethyl amine derivatives, including variations such as cyclohexanol and other cycloalkyl groups. The compounds are characterized by their specific chemical structure, which includes optional unsaturation and various substituents such as alkyl, hydroxyl, alkoxy, and other functional groups[4].
Pharmacological Use
The primary focus of the patent is on the antidepressant properties of these compounds. The inventors describe how these derivatives inhibit the reuptake of serotonin and norepinephrine, neurotransmitters that play crucial roles in mood regulation. This mechanism of action is central to the therapeutic efficacy of these compounds in treating depression and related disorders[4].
Claims of the Patent
Independent Claims
The patent includes several independent claims that define the scope of the invention. These claims specify the chemical structure of the compounds, including the core phenethylamine backbone and the various cycloalkyl and substituent groups. For example, Claim 1 describes the general formula for the compounds, while subsequent claims detail specific examples and variations[4].
Dependent Claims
Dependent claims further narrow down the scope by specifying particular substituents, such as alkyl groups, hydroxyl groups, and other functional groups. These claims ensure that the patent covers a range of compounds that fall within the defined structural parameters[4].
Patent Landscape
Related Patents and Developments
The patent landscape surrounding US 4,535,186 includes several related patents and developments. For instance, later patents such as US 7,807,195 B2 describe extended release formulations of Venlafaxine, which build upon the initial discovery and development of the compound[1].
Litigation and Legal Precedents
Patents related to Venlafaxine and its derivatives have been involved in various legal disputes. For example, the case of Pfizer Canada Inc v Apotex Inc involved allegations of overpromising, obviousness, and double patenting related to a different but related compound, O-desmethyl-venlafaxine (ODV). The Federal Court's decision in this case highlighted the importance of precise claim construction and the abolition of the promise doctrine in Canadian patent law[2].
Impact on Pharmaceutical Industry
Development of Venlafaxine
The patent played a crucial role in the development of Venlafaxine, which has become a significant medication in the treatment of depression and anxiety. Venlafaxine's unique mechanism of action, as described in the patent, has made it a preferred option for patients who do not respond well to other antidepressants.
Generic and Extended Release Formulations
Following the expiration of the original patent, generic versions of Venlafaxine have been developed. Additionally, extended release formulations, such as those described in US 7,807,195 B2, have been patented to improve the drug's delivery and efficacy[1].
Economic and Research Implications
Patent Scope and Claims Analysis
The analysis of patent claims, as facilitated by datasets like the USPTO's Patent Claims Research Dataset, provides valuable insights into the scope and breadth of patents. This dataset can help researchers and legal professionals understand the dependency relationships between claims and the overall patent scope, which is crucial for navigating the complex landscape of pharmaceutical patents[3].
Key Takeaways
- Chemical Structure and Derivatives: The patent describes a class of hydroxycycloalkanephenethyl amine derivatives with specific chemical structures.
- Pharmacological Use: These compounds are identified as antidepressants, inhibiting the reuptake of serotonin and norepinephrine.
- Claims: The patent includes independent and dependent claims that define the scope of the invention.
- Patent Landscape: The patent is part of a broader landscape that includes related patents and legal disputes.
- Impact on Industry: The patent has been instrumental in the development of Venlafaxine and its generic and extended release formulations.
FAQs
What is the main compound described in US 4,535,186?
The main compound described in US 4,535,186 is Venlafaxine, a serotonin and norepinephrine reuptake inhibitor.
What is the therapeutic use of the compounds described in the patent?
The compounds are used as antidepressants, specifically inhibiting the reuptake of serotonin and norepinephrine.
What are some of the related patents to US 4,535,186?
Related patents include those describing extended release formulations of Venlafaxine, such as US 7,807,195 B2.
How has the patent landscape evolved since the granting of US 4,535,186?
The patent landscape has evolved with the development of generic and extended release formulations, as well as legal disputes over related compounds.
What is the significance of the abolition of the promise doctrine in Canadian patent law?
The abolition of the promise doctrine, as seen in AstraZeneca Canada Inc v Apotex Inc, ensures that patent claims are not invalidated based on overpromising, which has implications for the validity and scope of pharmaceutical patents[2].
Sources
- US7807195.pdf - United States Patent - Extended Release Formulation of Venlafaxine Hydrochloride.
- Federal Court shoots down an attempted revival of the promise doctrine - PCKIP.
- Patent Claims Research Dataset - USPTO.
- US4535186A - 2-Phenyl-2-(1-hydroxycycloalkyl or 1-hydroxycycloalk-2-enyl)ethylamine derivatives - Google Patents.
