United States Patent 4,703,063: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,703,063, issued on October 27, 1987, is a significant patent in the pharmaceutical industry, particularly for the treatment of benign prostatic hyperplasia (BPH). This patent is associated with the drug tamsulosin hydrochloride, marketed under the brand name Flomax®. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background and Invention
The patent describes novel sulfamoyl-substituted phenethylamine derivatives that exhibit α-adrenergic blocking action, making them useful as antihypertensive agents. However, the primary focus of this patent is on tamsulosin hydrochloride, which is specifically indicated for the treatment of the functional symptoms of BPH[2][4].
Scope of the Patent
The scope of the patent encompasses the chemical compounds, their synthesis, and their pharmaceutical applications. Here are the key aspects:
Chemical Compounds
The patent details the synthesis and structure of sulfamoyl-substituted phenethylamine derivatives. These compounds are characterized by their α-adrenergic blocking activity, which is crucial for their therapeutic effects. Specifically, tamsulosin hydrochloride is highlighted as a potent and selective α1-adrenoceptor antagonist[1].
Pharmaceutical Applications
The primary application of tamsulosin hydrochloride is in the treatment of BPH. The patent describes its efficacy in alleviating the symptoms associated with this condition, such as urinary frequency, urgency, and weak stream[2][4].
Claims of the Patent
The claims of the patent are comprehensive and cover various aspects of the invention:
Compound Claims
The patent claims include the specific chemical structures of the sulfamoyl-substituted phenethylamine derivatives, including tamsulosin hydrochloride. These claims define the scope of the protected compounds and their isomers, salts, and other derivatives[1].
Process Claims
The patent also claims the methods for producing these compounds, including the synthesis steps and the reagents used. This ensures that not only the final product but also the process of making it is protected[1].
Pharmaceutical Formulation Claims
The claims extend to the pharmaceutical formulations containing tamsulosin hydrochloride, including capsules, tablets, and other dosage forms. This includes the excipients and the controlled release formulations that enhance the drug's efficacy and patient compliance[4].
Patent Landscape
The patent landscape surrounding US 4,703,063 is complex and involves several key players and legal battles.
Litigation and Settlements
Impax Laboratories, Inc. was involved in significant litigation regarding this patent. In 2009, Impax settled pending U.S. litigation with Astellas Pharma Inc. and Boehringer Ingelheim Pharmaceuticals, Inc., confirming the validity and infringement of the patent. This settlement allowed Impax to launch a generic version of tamsulosin hydrochloride in 2010, prior to the expiration of pediatric exclusivity[2].
Generic Competition
The settlement and subsequent generic launches marked a significant shift in the market for tamsulosin hydrochloride. The entry of generic competitors reduced the market share of the branded product, Flomax®, but also made the treatment more accessible and affordable for patients[2].
Controlled Release Formulations
Later patents, such as EP3473244A1, describe controlled release formulations of tamsulosin hydrochloride. These formulations involve embedding the drug in a controlled release matrix composed of cellulose derivatives, which provide prolonged or delayed release of the drug. This innovation aims to improve patient compliance by reducing the frequency of dosing[4].
Impact on the Pharmaceutical Industry
The patent and its associated litigation have had several impacts on the pharmaceutical industry:
Innovation and Competition
The patent protected the innovative work on tamsulosin hydrochloride, allowing the original patent holders to recoup their investment in research and development. However, the eventual entry of generic competitors increased market competition, driving down prices and expanding access to the medication[2].
Patent Quality and Scope
The debates around patent quality and scope are relevant here. The patent's claims were subject to scrutiny during litigation, and the settlement validated the patent's validity and infringement. This case highlights the importance of clear and well-defined patent claims to avoid unnecessary litigation and ensure innovation incentives[3].
Key Takeaways
- Chemical Compounds: The patent protects sulfamoyl-substituted phenethylamine derivatives, with a focus on tamsulosin hydrochloride.
- Pharmaceutical Applications: Tamsulosin hydrochloride is primarily used for treating BPH symptoms.
- Claims: The patent includes compound, process, and pharmaceutical formulation claims.
- Litigation and Settlements: Significant litigation led to a settlement allowing generic competition.
- Controlled Release Formulations: Later patents describe innovative controlled release formulations.
- Industry Impact: The patent influenced innovation, competition, and access to the medication.
FAQs
What is the primary use of tamsulosin hydrochloride as described in US 4,703,063?
Tamsulosin hydrochloride is primarily used for the treatment of the functional symptoms of benign prostatic hyperplasia (BPH).
Who were the parties involved in the litigation over US 4,703,063?
The litigation involved Impax Laboratories, Inc., Astellas Pharma Inc., and Boehringer Ingelheim Pharmaceuticals, Inc.
What was the outcome of the litigation over US 4,703,063?
The litigation resulted in a settlement confirming the validity and infringement of the patent, allowing Impax to launch a generic version of tamsulosin hydrochloride.
How has the patent landscape evolved for tamsulosin hydrochloride?
The patent landscape has evolved with the development of controlled release formulations and the entry of generic competitors.
What is the significance of the controlled release formulations of tamsulosin hydrochloride?
Controlled release formulations improve patient compliance by providing prolonged or delayed release of the drug, reducing the frequency of dosing.
Sources
- US4703063A - Sulfamoyl substituted phenethylamine derivatives and process of producing them - Google Patents
- Impax Laboratories Settles Pending Litigation for FLOMAX® - Amneal Pharmaceuticals, Inc.
- Patent Claims and Patent Scope - SSRN
- EP3473244A1 - Controlled release oral tamsulosin hydrochloride - Google Patents
