Detailed Analysis of the Scope and Claims of United States Patent 4,396,598
Introduction
United States Patent 4,396,598, granted on August 2, 1983, to Mallinckrodt, Inc., is a significant patent in the field of radiological compositions, particularly for X-ray contrast agents. This patent, invented by Youlin Lin, introduces new compounds and methods for their preparation and use.
Background of the Invention
The invention addresses the need for improved X-ray contrast agents, which are crucial for diagnostic imaging. Prior to this patent, existing contrast agents had various limitations, including toxicity and inadequate visualization. The introduction of non-ionic, water-soluble iodinated compounds marked a significant advancement in X-ray diagnosis[4].
Claims and Scope
Main Claims
The patent primarily claims a new compound, N,N'-bis(2,3-dihydroxypropyl)-5-N-(2-hydroxyethyl)glycolamido-2,4,6-triiodoisophthalamide, and its use in radiological compositions. The claims include:
- The chemical compound itself.
- Radiological compositions containing this compound.
- Methods for preparing these compositions.
- The use of these compositions for X-ray visualization[1].
Preparation Method
The patent describes a detailed method for synthesizing the compound. This involves the reaction of glycolic acid with acetyl chloride, followed by further reactions involving dimethylacetamide (DMAC) and acid chloride. The process includes specific temperature controls and purification steps to ensure the quality of the final product[1].
Use in Radiological Compositions
The patent specifies that the new compound is used in a pharmaceutically acceptable radiological vehicle. This composition is designed to provide satisfactory X-ray visualization when injected in sufficient amounts. The use of this compound enhances the diagnostic capabilities by offering better contrast and reduced toxicity compared to previous agents[1].
Patent Landscape
Related Patents
Other patents in the field of X-ray contrast agents include those related to the purification and preparation of non-ionic, water-soluble iodinated compounds. For example, US Patent 7,282,607 B2 describes a process for the purification of such compounds, highlighting the ongoing advancements in this area[4].
Patent Term Extensions
Patents in the pharmaceutical and medical fields can be subject to term extensions under 35 U.S.C. 156(e)(1) due to regulatory reviews by the FDA. While US Patent 4,396,598 does not appear to have been extended under this provision, understanding these regulations is crucial for managing patent lifetimes in this sector[2].
Impact on the Industry
Innovation and Advancements
The invention described in US Patent 4,396,598 contributed significantly to the development of safer and more effective X-ray contrast agents. This advancement has been part of a broader trend in diagnostic imaging, where the introduction of non-ionic iodinated compounds has improved patient safety and diagnostic accuracy[4].
Competitive Landscape
The patent landscape in this field is highly competitive, with multiple companies and inventors working on similar technologies. For instance, Bracco Imaging, S.p.A., has developed several patents related to the preparation and purification of contrast agents, indicating a dynamic and innovative environment[4].
Patent Scope Metrics
Research on patent scope often uses metrics such as independent claim length and independent claim count to assess the breadth and clarity of patent claims. While these metrics are not directly applied to US Patent 4,396,598 in the available literature, they are relevant for understanding the overall quality and scope of patents in this field. Narrower claims, as seen in the examination process, are often associated with higher grant probabilities and shorter examination times[3].
Citations and References
The patent cites several prior art references, including other patents related to the synthesis and use of iodinated compounds. These citations highlight the evolutionary nature of the invention and its place within the broader context of radiological contrast agents[1].
Highlight from the Patent
"In a method for X-ray visualization wherein a radiological composition containing an X-ray contrast agent in a pharmaceutically acceptable radiological vehicle is injected in a sufficient amount to provide adequate visualization and thereafter X-ray visualization carried out, the improvement comprising or utilizing as the radiological composition a composition containing N,N'-bis(2,3-dihydroxypropyl)-5-N-(2-hydroxyethyl)glycolamido-2,4,6-triiodoisophthalamide in a sufficient amount to provide satisfactory X-ray visualization together with a pharmaceutically acceptable radiological vehicle."[1]
Key Takeaways
- New Compound: The patent introduces a new X-ray contrast agent, N,N'-bis(2,3-dihydroxypropyl)-5-N-(2-hydroxyethyl)glycolamido-2,4,6-triiodoisophthalamide.
- Preparation Method: Detailed synthesis steps are provided, ensuring the quality and purity of the compound.
- Radiological Use: The compound is used in a pharmaceutically acceptable vehicle for enhanced X-ray visualization.
- Industry Impact: The invention has contributed to safer and more effective diagnostic imaging.
- Patent Landscape: The patent is part of a competitive and innovative field with ongoing advancements in contrast agent technology.
FAQs
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What is the main compound claimed in US Patent 4,396,598?
- The main compound is N,N'-bis(2,3-dihydroxypropyl)-5-N-(2-hydroxyethyl)glycolamido-2,4,6-triiodoisophthalamide.
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How is the compound prepared according to the patent?
- The preparation involves reactions with glycolic acid, acetyl chloride, and further steps using DMAC and acid chloride, with specific temperature controls and purification.
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What is the significance of this patent in the field of X-ray contrast agents?
- It introduces a safer and more effective non-ionic, water-soluble iodinated compound for diagnostic imaging.
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Can the term of this patent be extended under 35 U.S.C. 156(e)(1)?
- While possible, there is no indication in the available literature that this patent was extended under this provision.
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How does this patent fit into the broader patent landscape for radiological contrast agents?
- It is part of a competitive and innovative field with ongoing advancements in the preparation and purification of contrast agents.
Cited Sources
- US Patent for Triiodoisophthalamide X-ray contrast agent - Justia Patents.
- Extension Under 35 U.S.C. 156(e)(1) - United States Patent and Trademark Office.
- Patent Claims and Patent Scope - SSRN.
- United States Patent - googleapis.com - US7282607B2.
