United States Patent 4,355,032: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,355,032, issued on October 19, 1982, is a significant patent in the field of pharmaceuticals, particularly for its antiviral properties. This patent, assigned to Burroughs-Wellcome Co., now part of GlaxoSmithKline, covers the compound 9-(1,3-dihydroxy-2-propoxymethyl)guanine and its pharmaceutically acceptable salts.
Background of the Patent
The patent was filed on June 12, 1979, and granted nearly three years later. It is part of a broader class of antiviral compounds that were being developed during the late 1970s and early 1980s to combat various viral infections.
Scope of the Patent
Compound Description
The patent describes the compound 9-(1,3-dihydroxy-2-propoxymethyl)guanine, which is a nucleoside analog. This compound and its pharmaceutically acceptable salts are identified as having potent antiviral activity, particularly against herpes simplex virus and other related viruses[5].
Claims
The patent includes several claims that define the scope of the invention:
- Claim 1: The compound 9-(1,3-dihydroxy-2-propoxymethyl)guanine.
- Claim 2: Pharmaceutically acceptable salts of the compound.
- Claim 3: Methods for preparing the compound.
- Claim 4: Pharmaceutical compositions containing the compound or its salts.
- Claim 5: Methods for treating viral infections using the compound or its salts[5].
Claims Analysis
Independent Claims
The independent claims (Claims 1 and 4) are crucial as they define the core invention. Claim 1 specifies the chemical structure of the compound, while Claim 4 outlines the pharmaceutical compositions that can be made using this compound.
Dependent Claims
Dependent claims (Claims 2, 3, and 5) build upon the independent claims by specifying additional aspects such as the preparation methods, pharmaceutical compositions, and therapeutic uses. These claims provide a broader protection by covering various aspects of the invention.
Patent Landscape
Related Patents
The patent landscape for antiviral compounds in the late 1970s and early 1980s was highly competitive. Several other patents were filed around the same time, covering similar nucleoside analogs. For example, patents like US Patent 4,211,771, also assigned to Burroughs-Wellcome Co., covered other antiviral compounds, indicating a robust research and development effort in this area[5].
International Patent Filings
To understand the global reach of this patent, it is essential to look at international filings. The Global Dossier service provided by the USPTO allows users to see the patent family for a specific application, including related applications filed at participating IP Offices. This would reveal if similar patents were filed in other countries, such as through the European Patent Office (EPO) or the Japan Patent Office (JPO)[1].
Expiration and Generic Entry
The patent expired in 1999, after the standard 17-year term from the date of issuance. Following its expiration, generic versions of the antiviral drug could be developed and marketed. This is a common scenario where the expiration of a patent opens up the market for generic competition[2].
Economic and Market Impact
Market Dominance
During its active period, the patent provided Burroughs-Wellcome Co. with a significant market advantage in the antiviral drug market. The exclusive rights granted by the patent allowed the company to recoup its research and development investments and generate substantial revenue.
Generic Competition
After the patent expired, generic versions of the drug entered the market, increasing competition and reducing prices. This shift benefited consumers by providing more affordable treatment options but reduced the market share and revenue of the original patent holder.
Search and Analysis Tools
USPTO Resources
To conduct a thorough analysis of this patent, one can use various resources provided by the USPTO, such as the Patent Public Search tool, which offers enhanced access to prior art and related patent documents. The Global Dossier and Common Citation Document (CCD) services are also valuable for understanding the international and citation landscape of the patent[1].
Patent Claims Research Dataset
The USPTO's Patent Claims Research Dataset can provide detailed information on claims from US patents, including those related to this patent. This dataset can help in analyzing the scope and dependency relationships between claims, offering insights into the patent's breadth and depth[3].
Conclusion
United States Patent 4,355,032 is a pivotal patent in the field of antiviral medications, covering a specific nucleoside analog with significant therapeutic potential. Understanding the scope, claims, and patent landscape of this invention provides valuable insights into the development and commercialization of antiviral drugs.
Key Takeaways
- Compound and Claims: The patent covers the compound 9-(1,3-dihydroxy-2-propoxymethyl)guanine and its pharmaceutically acceptable salts.
- Patent Expiration: The patent expired in 1999, allowing for generic competition.
- Market Impact: The patent provided a market advantage during its active period but led to increased competition post-expiration.
- Search Tools: USPTO resources like Patent Public Search, Global Dossier, and the Patent Claims Research Dataset are essential for thorough analysis.
FAQs
Q: What is the compound described in US Patent 4,355,032?
A: The compound is 9-(1,3-dihydroxy-2-propoxymethyl)guanine, a nucleoside analog with antiviral properties.
Q: When was US Patent 4,355,032 issued and when did it expire?
A: The patent was issued on October 19, 1982, and it expired in 1999.
Q: What are the key claims of US Patent 4,355,032?
A: The key claims include the compound itself, its pharmaceutically acceptable salts, methods for preparing the compound, pharmaceutical compositions, and methods for treating viral infections.
Q: How can one analyze the international patent filings related to this patent?
A: Using the Global Dossier service provided by the USPTO, one can see the patent family for this application, including related applications filed at participating IP Offices.
Q: What impact did the expiration of this patent have on the market?
A: The expiration led to the entry of generic versions of the drug, increasing competition and reducing prices, which benefited consumers but reduced the market share of the original patent holder.
Sources
- USPTO, "Search for patents - USPTO," https://www.uspto.gov/patents/search
- DrugPatentWatch, "Drugs covered by patent 4,355,032. Claims, international patent ...," https://www.drugpatentwatch.com/p/patent/4355032
- USPTO, "Patent Claims Research Dataset - USPTO," https://www.uspto.gov/ip-policy/economic-research/research-datasets/patent-claims-research-dataset
- Commerce.gov, "U.S. Patent and Trademark Office | U.S. Department of Commerce," https://www.commerce.gov/bureaus-and-offices/uspto
- PatentBuddy, "Analytics for US Patent No. 4355032, 9-(1,3-Dihydroxy-2 ...," http://www.patentbuddy.com/Patent/4355032
