United States Patent 5,490,987: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,490,987, titled "Tableting of colestipol hydrochloride," is a significant patent in the pharmaceutical field, particularly in the formulation and manufacturing of colestipol hydrochloride tablets. This patent, issued to address specific challenges in tablet formulation, provides a comprehensive method for preparing stable and effective colestipol hydrochloride tablets.
Background of Colestipol Hydrochloride
Colestipol hydrochloride is a bile acid sequestrant used primarily to treat hypercholesterolemia. It works by binding to bile acids in the intestine, which are then excreted, reducing the amount of cholesterol produced in the liver[2].
Scope of the Patent
The patent US 5,490,987 focuses on the tableting process of colestipol hydrochloride, addressing several critical aspects:
Physical Characteristics of the Tablets
The patent describes the physical characteristics of the tablets, including their composition and the process for preparing them. The tablets are designed to contain colestipol hydrochloride in a form effective for treating or preventing hypercholesterolemia. The physical characteristics include the tablet's size, shape, and coating to ensure stability and efficacy[1].
Tablet Composition
The tablets comprise colestipol hydrochloride as the active ingredient, along with other excipients such as povidone, which is added to a slurry of fine-milled colestipol hydrochloride to enhance tablet formation. The patent specifies the preferred amounts and types of these ingredients to achieve optimal tablet properties[1].
Coating Process
The patent details a coating process that includes a clear coating made from hydroxypropyl methylcellulose and triacetin. This coating is designed to maintain the structural integrity of the tablets when exposed to humid air and to ensure that the disintegration time is not significantly delayed. The specific amounts of these coating ingredients are also provided[1].
Claims of the Patent
The patent includes several claims that define the scope of the invention:
Claim 1: Pharmaceutical Tablet Composition
The first claim describes a pharmaceutical tablet that includes colestipol hydrochloride effective for treating or preventing hypercholesterolemia. The tablet has specific physical characteristics, including a clear coating to maintain stability[1].
Claim 2: Process for Preparing the Tablets
This claim outlines the process for preparing the tablets, including the addition of povidone to a slurry of fine-milled colestipol hydrochloride and the application of a clear coating[1].
Claim 3: Coating Specifications
The patent claims specific amounts and types of coating ingredients, such as hydroxypropyl methylcellulose and triacetin, to ensure the tablets' stability and efficacy[1].
Patent Landscape
The patent landscape surrounding US 5,490,987 involves several related patents and technologies:
Prior Art
Prior patents, such as U.S. Pat. No. 4,439,419 and U.S. Pat. No. 4,631,305, disclose methods for using colestipol hydrochloride to treat hyperacidity and as a tablet disintegrating agent, respectively. However, these patents do not address the specific tablet formulation and coating process described in US 5,490,987[1][2].
Related Patents
The patent WO1990002148A1 describes fine-beaded colestipol hydrochloride and its use in reducing hypercholesterolemia. While it shares some similarities with US 5,490,987, it does not detail the same tablet formulation and coating process[2].
Impact on Pharmaceutical Manufacturing
The patent US 5,490,987 has significant implications for pharmaceutical manufacturing:
Improved Tablet Stability
The clear coating process described in the patent ensures that the tablets maintain their structural integrity even in humid conditions, which is crucial for their stability and shelf life[1].
Enhanced Efficacy
The specific formulation and coating process ensure that the colestipol hydrochloride is released effectively, enhancing the tablet's efficacy in treating hypercholesterolemia[1].
Compliance with Regulatory Standards
The patent's detailed specifications for tablet composition and coating help manufacturers comply with regulatory standards, ensuring the quality and safety of the final product[4].
Legal and Exclusivity Aspects
The patent's legal status and exclusivity aspects are important considerations:
Expiration and Lifetime
The patent has expired, which means that the technology described is now in the public domain. This allows other manufacturers to use the described methods without infringing on the original patent[1].
Patent Scope and Quality
The scope and quality of the patent claims are critical. Research on patent scope suggests that narrower claims, like those in US 5,490,987, are often associated with a higher probability of grant and a shorter examination process. This indicates that the patent's claims were well-defined and specific, contributing to its approval[3].
Key Takeaways
- Specific Formulation: The patent describes a specific formulation of colestipol hydrochloride tablets, including the use of povidone and a clear coating.
- Stability and Efficacy: The coating process ensures tablet stability and efficacy, even in humid conditions.
- Regulatory Compliance: The detailed specifications help manufacturers comply with regulatory standards.
- Public Domain: The patent has expired, making the technology publicly available.
- Narrow Claims: The patent's narrow and specific claims contributed to its approval and shorter examination process.
FAQs
What is the primary use of colestipol hydrochloride?
Colestipol hydrochloride is primarily used to treat hypercholesterolemia by binding to bile acids in the intestine.
What is unique about the coating process described in the patent?
The coating process involves using hydroxypropyl methylcellulose and triacetin to maintain the structural integrity of the tablets in humid conditions without delaying disintegration.
Has the patent expired?
Yes, the patent US 5,490,987 has expired, making the described technology publicly available.
How does the patent contribute to pharmaceutical manufacturing?
The patent provides a detailed method for preparing stable and effective colestipol hydrochloride tablets, ensuring compliance with regulatory standards and enhancing the product's efficacy.
What are the implications of the patent's claims being narrow and specific?
Narrow and specific claims, as seen in this patent, are associated with a higher probability of grant and a shorter examination process, indicating well-defined and valid claims.
Sources
- US5490987A - Tableting of colestipol hydrochloride - Google Patents
- WO1990002148A1 - Fine-beaded colestipol hydrochloride - Google Patents
- Patent Claims and Patent Scope - Hoover Institution
- Approved Drug Products - DrugPatentWatch
