Detailed Analysis of the Scope and Claims of United States Patent 4,092,315
Introduction
United States Patent 4,092,315, titled "Novel crystalline forms of prazosin hydrochloride," is a significant patent in the pharmaceutical field, particularly in the development of antihypertensive agents. This patent, granted in 1978, discloses novel crystalline forms of prazosin hydrochloride, which is a crucial medication for treating hypertension.
Background of Prazosin Hydrochloride
Prazosin hydrochloride is an alpha-adrenergic blocker used primarily to treat high blood pressure and symptoms of benign prostatic hyperplasia. The patent focuses on the development of new crystalline forms of this compound, which is essential for its stability, efficacy, and manufacturing process[1].
Scope of the Patent
The scope of the patent is centered around the novel crystalline forms of prazosin hydrochloride, including anhydrous and hydrated forms. Here are the key aspects:
Anhydrous Forms
The patent highlights the anhydrous α-form of prazosin hydrochloride as the preferred form due to its stability and ease of manufacture. This form is obtained through specific processes involving heat treatment and solvent crystallization[1].
Hydrated Forms
In addition to the anhydrous forms, the patent also describes various hydrated forms of prazosin hydrochloride. These forms are characterized by their water content and are produced through different crystallization methods[1].
Claims of the Patent
The claims of the patent are detailed and specific, ensuring broad protection for the novel crystalline forms of prazosin hydrochloride:
Manufacturing Process
The patent claims cover the methods for preparing these crystalline forms, including heat treatment, solvent crystallization, and precipitation. These processes are critical for ensuring the purity and stability of the final product[1].
Physical and Chemical Properties
The claims also describe the physical and chemical properties of the novel crystalline forms, such as their X-ray diffraction patterns, IR spectra, and thermogravimetric analysis. These properties are essential for identifying and characterizing the different forms of prazosin hydrochloride[1].
Pharmaceutical Applications
The patent includes claims related to the pharmaceutical applications of these novel crystalline forms, emphasizing their use as antihypertensive agents. This includes formulations and compositions that incorporate these crystalline forms[1].
Patent Landscape
Related Patents
Other patents, such as U.S. Patent 4,601,897, build upon the discoveries made in U.S. Patent 4,092,315. For example, the combination of prazosin with pirbuterol for bronchodilation is described, where the preferred form of prazosin is the monohydrochloride salt, especially the α-form disclosed in U.S. Patent 4,092,315[4].
Impact on Pharmaceutical Development
The patent has had a significant impact on the development of pharmaceuticals, particularly in the field of antihypertensive medications. The novel crystalline forms of prazosin hydrochloride have improved the stability, efficacy, and manufacturability of this drug, making it a more reliable treatment option for patients.
Metrics for Measuring Patent Scope
To understand the scope of this patent, metrics such as independent claim length and independent claim count can be used. These metrics help in assessing the breadth and clarity of the patent claims. For instance, narrower claims, as seen in the examination process of this patent, are associated with a higher probability of grant and a shorter examination process[3].
Legal and Regulatory Aspects
The patent has undergone the standard legal and regulatory processes. It was granted in 1978 and has since expired, as is typical for patents with a 20-year term from the date of filing. The legal status and validity of the patent would have been subject to scrutiny during its active period, ensuring that it met all the criteria for patentability[1].
Conclusion
United States Patent 4,092,315 is a pivotal patent in the pharmaceutical industry, particularly in the development of antihypertensive agents. The patent's scope and claims are well-defined, covering novel crystalline forms of prazosin hydrochloride, their manufacturing processes, and their pharmaceutical applications. The impact of this patent on the pharmaceutical landscape is significant, and it serves as a foundation for further innovations in the field.
Key Takeaways
- Novel Crystalline Forms: The patent introduces novel anhydrous and hydrated crystalline forms of prazosin hydrochloride.
- Manufacturing Processes: Specific methods for preparing these forms, including heat treatment and solvent crystallization.
- Pharmaceutical Applications: The patent covers the use of these forms as antihypertensive agents.
- Impact on Pharmaceutical Development: Improved stability, efficacy, and manufacturability of prazosin hydrochloride.
- Patent Metrics: Narrower claims associated with higher grant probability and shorter examination process.
FAQs
What is the main subject of United States Patent 4,092,315?
The main subject is the novel crystalline forms of prazosin hydrochloride, an antihypertensive agent.
What are the preferred forms of prazosin hydrochloride described in the patent?
The preferred form is the anhydrous α-form of prazosin hydrochloride.
How are the novel crystalline forms of prazosin hydrochloride prepared?
They are prepared through methods such as heat treatment, solvent crystallization, and precipitation.
What is the significance of this patent in the pharmaceutical industry?
It improves the stability, efficacy, and manufacturability of prazosin hydrochloride, making it a more reliable treatment option.
Are there related patents that build upon this discovery?
Yes, patents like U.S. Patent 4,601,897 combine prazosin with other drugs for different therapeutic uses.
Sources
- US4092315A - Novel crystalline forms of prazosin hydrochloride - Google Patents
- United States Patent (19) - googleapis.com
- Patent Claims and Patent Scope - SSRN
- United States Patent (19) - googleapis.com (Prazosin-pirbuterol combination)
