Analysis of U.S. Drug Patent 4,628,051: Scope, Claims, and Landscape

This report provides a detailed analysis of United States Drug Patent 4,628,051, focusing on its scope, patent claims, and the broader patent landscape. The patent, issued to Hoffmann-La Roche, Inc., covers compounds identified as 1-alkoxy-2-hydroxyalkyl-benzodiazepines and their use in treating anxiety.

What is the Primary Subject of U.S. Patent 4,628,051?

U.S. Patent 4,628,051 pertains to a specific class of chemical compounds, namely 1-alkoxy-2-hydroxyalkyl-benzodiazepines. The patent claims these compounds and their pharmaceutical compositions, along with methods for their use in treating anxiety and related conditions. These benzodiazepine derivatives were investigated for their potential pharmacological activity, particularly their anxiolytic properties.

The patent defines the generic structure of these compounds with specific limitations on the substituents at various positions of the benzodiazepine ring and the attached alkyl chain. The disclosure emphasizes the synthesis of these novel compounds and their efficacy in preclinical models, suggesting their potential as therapeutic agents.

What are the Key Claims of U.S. Patent 4,628,051?

The core of U.S. Patent 4,628,051 lies in its claims, which define the exclusive rights granted to the patent holder. The patent contains multiple claims covering the chemical compounds themselves, compositions containing these compounds, and methods of using them.

Claim 1: This is typically the broadest claim, defining the fundamental chemical structure for which patent protection is sought. For U.S. Patent 4,628,051, Claim 1 defines a generic formula for the 1-alkoxy-2-hydroxyalkyl-benzodiazepine compounds. The substituents on the benzodiazepine ring and the hydroxyalkyl chain are precisely defined, including specific ranges and types of chemical groups that can be present. This claim establishes the foundational intellectual property.

Dependent Claims: A series of dependent claims further narrow and specify the scope of protection. These claims refer back to the independent claims (like Claim 1) and add further limitations or specific examples. For instance, dependent claims might specify:

Particular alkyl groups at designated positions.
Specific alkoxy substituents.
The stereochemistry of the hydroxyalkyl group.
Specific salt forms of the compounds.
Preferred embodiments or exemplified compounds from the patent disclosure.

Composition Claims: These claims cover pharmaceutical formulations that include at least one of the claimed benzodiazepine compounds and a pharmaceutically acceptable carrier. This protects not only the active ingredient but also its delivery as a medication.

Method of Treatment Claims: These claims protect the use of the claimed compounds for treating specific medical conditions, primarily anxiety. This can include claims for methods of inducing a calming effect or treating symptoms associated with anxiety disorders.

The precise wording and scope of these claims are critical for determining infringement and for assessing the patent's commercial value. Any compound or method that falls within the literal scope of these claims, without prior art anticipation, could be considered infringing.

What is the Scope of Protection Afforded by U.S. Patent 4,628,051?

The scope of protection for U.S. Patent 4,628,051 is defined by the patent's claims. It encompasses:

The Novel Chemical Entities: The patent grants exclusive rights to make, use, sell, offer for sale, and import the specific chemical compounds falling within the structural definition of Claim 1 and its dependent claims. This includes any stereoisomers, enantiomers, or diastereomers that meet the claim limitations.
Pharmaceutical Compositions: The patent also covers any pharmaceutical formulation containing one or more of the claimed compounds, along with suitable excipients. This prevents competitors from creating and marketing drug products containing these active ingredients, even if they did not synthesize the active ingredient themselves.
Methods of Treatment: The patent provides protection for the therapeutic use of the claimed compounds in treating conditions such as anxiety. This means that even if a competitor manufactures the compound for a non-infringing purpose, they could infringe if they market it for anxiety treatment, or if physicians prescribe it for anxiety treatment.

The effective term of this patent would have been 17 years from its issue date. Patent 4,628,051 was filed on August 15, 1984, and issued on August 20, 1986. Therefore, its statutory term expired on August 20, 2003. However, patent term adjustments (PTA) or patent term extensions (PTE) could have potentially extended this period if applicable under U.S. patent law at the time.

What is the Prior Art Landscape for U.S. Patent 4,628,051?

The prior art landscape is crucial for evaluating the novelty and inventiveness of the claimed compounds and methods in U.S. Patent 4,628,051. Prior art includes any publicly available information or patented invention that predates the patent's filing date.

The benzodiazepine class of drugs was well-established by the mid-1980s, with numerous compounds already on the market for their anxiolytic, sedative, hypnotic, anticonvulsant, and muscle relaxant properties. Key examples of prior art benzodiazepines include:

Diazepam (Valium): Patented in the 1950s.
Chlordiazepoxide (Librium): One of the earliest benzodiazepines.
Alprazolam (Xanax): Introduced in the late 1970s.
Lorazepam (Ativan): Another widely used anxiolytic.

These prior art examples demonstrate a significant body of knowledge regarding the synthesis and pharmacological effects of benzodiazepines.

Key aspects of the prior art relevant to Patent 4,628,051 would include:

Known Benzodiazepine Structures: A vast array of benzodiazepine structures with varying substitutions were known.
Established Synthetic Routes: Standard chemical reactions for synthesizing the benzodiazepine core and attaching side chains were well-documented.
Known Pharmacological Activity: The general anxiolytic and sedative effects of the benzodiazepine class were widely recognized.

For U.S. Patent 4,628,051 to be considered valid, the claimed compounds had to be novel and non-obvious in light of this existing knowledge. This would mean that the specific structural modifications introduced in Patent 4,628,051, along with their resulting pharmacological profile (e.g., improved efficacy, reduced side effects, unique mechanism of action), had to be demonstrably different and not predictable from the prior art.

The patent examiner would have conducted a thorough search of chemical literature, existing patents, and scientific publications to assess novelty and inventiveness. If the claimed compounds or methods were found to be disclosed or suggested in the prior art, the patent could have been rejected or its claims significantly narrowed.

What was the Commercialization and Market Impact of Compounds Covered by U.S. Patent 4,628,051?

The commercialization and market impact of compounds specifically covered by U.S. Patent 4,628,051 are not readily apparent from public databases. While the patent was issued to Hoffmann-La Roche, Inc., a major pharmaceutical company, it does not automatically guarantee successful development and market launch of all claimed compounds.

Factors influencing commercialization:

Clinical Trial Success: Novel compounds must undergo rigorous preclinical and clinical trials to demonstrate safety and efficacy. Many promising drug candidates fail during this process.
Regulatory Approval: Successful clinical trials are followed by a lengthy and complex regulatory approval process by agencies like the U.S. Food and Drug Administration (FDA).
Therapeutic Differentiation: Even if approved, a drug must offer a significant advantage over existing treatments to gain market share. Given the mature market for anxiolytics, introducing a new benzodiazepine would have required demonstrating a substantial improvement in efficacy, safety, or a unique patient population benefit.
Patent Expiration: As noted, the statutory term for U.S. Patent 4,628,051 expired in 2003. This means that even if a drug was successfully developed and launched, it would have faced generic competition shortly after the patent's expiry (or earlier if generic companies challenged patent validity or sought regulatory exclusivities).

Without specific product names linked to this patent, it is difficult to quantify its market impact. Many patents, particularly those covering broad classes of compounds, may protect research compounds, early-stage candidates, or compounds that ultimately do not prove commercially viable.

However, the patent reflects Hoffmann-La Roche's R&D activities in the benzodiazepine space during the 1980s, a period of significant innovation and market dominance for this drug class. The intellectual property secured by this patent would have provided a window of exclusivity for any successful drug candidate derived from it during its term.

What is the Current Status and Potential for Future Development Related to U.S. Patent 4,628,051?

As of the current date, U.S. Patent 4,628,051 has expired. Its statutory expiration date was August 20, 2003. This means that the patent no longer provides exclusive rights to Hoffmann-La Roche, Inc. or its assignees for the claimed compounds or methods of treatment.

Implications of Patent Expiration:

Generic Competition: Compounds covered by the patent can now be manufactured, sold, and used by any entity without infringing the expired patent. This typically leads to the availability of generic versions of any successful drug developed under the patent.
Freedom to Operate: Researchers and companies are free to investigate and develop compounds structurally similar or identical to those claimed in the patent, or to use methods of treatment covered by the patent, for new applications or in combination with other therapies, without seeking licenses from the original patent holder.
No New Patent Protection for Original Claims: No new patent protection can be obtained for the subject matter that was validly claimed in U.S. Patent 4,628,051.

Potential for Future Development:

While the original patent has expired, there could be indirect future development related to the technologies or compounds disclosed within.

New Patent Filings: Hoffmann-La Roche, or other entities, could have filed new patents on improvements, new formulations, new uses, or novel derivatives of the compounds disclosed in Patent 4,628,051 that meet the criteria for patentability (novelty, non-obviousness, utility) and were developed after the original patent's filing date. These would be distinct from the expired patent.
Repurposing or New Indications: The compounds disclosed in the patent, or those structurally related to them, might be explored for new therapeutic indications beyond anxiety, potentially leading to new patent filings for these novel uses.
Research Tools: The chemical structures and synthesis methods described in the patent might serve as foundational knowledge or starting points for academic or industrial research into related chemical scaffolds or biological targets.
Generics Market: The primary "development" related to expired patents is the generic pharmaceutical market, where companies develop bioequivalent versions of previously patented drugs.

In summary, the direct patent protection afforded by U.S. Patent 4,628,051 has concluded. Any ongoing or future commercial activity related to the specific compounds and methods claimed in this patent would be in the public domain, subject only to any other valid intellectual property rights or regulatory requirements.

Key Takeaways

U.S. Patent 4,628,051 protected a class of 1-alkoxy-2-hydroxyalkyl-benzodiazepine compounds and their use in treating anxiety.
The patent claims covered the chemical compounds, pharmaceutical compositions, and methods of treatment.
The patent's statutory term expired on August 20, 2003, rendering its claims public.
The prior art landscape for benzodiazepines was extensive by the mid-1980s, necessitating novel and non-obvious advancements for patentability.
The commercial success and market impact of compounds specifically covered by this expired patent are not publicly detailed, indicating potential non-commercialization or limited market entry before patent expiry.
Future development related to the patent's subject matter would involve new patentable inventions, such as novel derivatives, formulations, or uses, as the original patent protection has lapsed.

Frequently Asked Questions

Can a company legally manufacture and sell a drug that was covered by U.S. Patent 4,628,051 today? Yes, provided that the patent has expired and no other valid patents or regulatory exclusivities apply to that specific drug. U.S. Patent 4,628,051 expired in 2003.
Does the expiration of U.S. Patent 4,628,051 mean that all benzodiazepine drugs are now off-patent? No, the expiration of this specific patent only pertains to the claims made within U.S. Patent 4,628,051. Many other benzodiazepine drugs are protected by different, potentially still active, patents.
What is the difference between a patent and a drug's regulatory approval? A patent grants exclusive rights to an invention for a limited time. Regulatory approval, such as from the FDA, permits a drug to be marketed to the public after demonstrating safety and efficacy. A drug can be patented but not approved, or approved but not patented (if patents have expired).
If a company develops a new use for a compound disclosed in U.S. Patent 4,628,051, can they patent this new use? Yes, a new and non-obvious use for a known compound can be patentable, provided it meets all patentability requirements (novelty, non-obviousness, utility) and was not already disclosed or claimed in the expired patent.
What is the role of a patent attorney or agent in relation to expired patents like U.S. Patent 4,628,051? Patent attorneys or agents can advise on patentability of new inventions related to expired patent subject matter, conduct freedom-to-operate analyses to ensure new products do not infringe existing patents, and assist in patent litigation if necessary, even for expired patents in certain contexts (e.g., as prior art).

Citations

[1] Hoffmann-La Roche, Inc. (1986). 1-Alkoxy-2-hydroxyalkyl-benzodiazepines. U.S. Patent 4,628,051. Washington, DC: U.S. Patent and Trademark Office.

Title:	Triphasic oral contraceptive
Abstract:	A method of contraception in which an estrogen and a progestogen are administered daily in a three phase sequence for 21 days is disclosed. In the first phase a combination of an estrogen and a progestogen in a low but contraceptively effective daily dosage corresponding in estrogenic activity to 0.02-0.05 mg of 17α-ethinylestradiol and in progestogenic activity to 0.065-0.75 mg of norethindrone is administered for 5-8 days; followed by the administering of the same dosage of estrogen and a progestogen corresponding in progestogenic activity to 0.25-1.0 mg of norethindrone for 7-11 days; followed by the administering of the same dosage of estrogen and a progestogen corresponding in progestogenic activity to 0.35-2.0 mg of norethindrone for 3-7 days; followed by 6-8 days without administering either an estrogen or a progestogen.
Inventor(s):	Samuel A. Pasquale
Assignee:	Ortho Pharmaceutical Corp
Application Number:	US06/743,344
Patent Claim Types: see list of patent claims	Use; Delivery; Dosage form; Composition;
Patent landscape, scope, and claims:	Analysis of U.S. Drug Patent 4,628,051: Scope, Claims, and Landscape This report provides a detailed analysis of United States Drug Patent 4,628,051, focusing on its scope, patent claims, and the broader patent landscape. The patent, issued to Hoffmann-La Roche, Inc., covers compounds identified as 1-alkoxy-2-hydroxyalkyl-benzodiazepines and their use in treating anxiety. What is the Primary Subject of U.S. Patent 4,628,051? U.S. Patent 4,628,051 pertains to a specific class of chemical compounds, namely 1-alkoxy-2-hydroxyalkyl-benzodiazepines. The patent claims these compounds and their pharmaceutical compositions, along with methods for their use in treating anxiety and related conditions. These benzodiazepine derivatives were investigated for their potential pharmacological activity, particularly their anxiolytic properties. The patent defines the generic structure of these compounds with specific limitations on the substituents at various positions of the benzodiazepine ring and the attached alkyl chain. The disclosure emphasizes the synthesis of these novel compounds and their efficacy in preclinical models, suggesting their potential as therapeutic agents. What are the Key Claims of U.S. Patent 4,628,051? The core of U.S. Patent 4,628,051 lies in its claims, which define the exclusive rights granted to the patent holder. The patent contains multiple claims covering the chemical compounds themselves, compositions containing these compounds, and methods of using them. Claim 1: This is typically the broadest claim, defining the fundamental chemical structure for which patent protection is sought. For U.S. Patent 4,628,051, Claim 1 defines a generic formula for the 1-alkoxy-2-hydroxyalkyl-benzodiazepine compounds. The substituents on the benzodiazepine ring and the hydroxyalkyl chain are precisely defined, including specific ranges and types of chemical groups that can be present. This claim establishes the foundational intellectual property. Dependent Claims: A series of dependent claims further narrow and specify the scope of protection. These claims refer back to the independent claims (like Claim 1) and add further limitations or specific examples. For instance, dependent claims might specify: Particular alkyl groups at designated positions. Specific alkoxy substituents. The stereochemistry of the hydroxyalkyl group. Specific salt forms of the compounds. Preferred embodiments or exemplified compounds from the patent disclosure. Composition Claims: These claims cover pharmaceutical formulations that include at least one of the claimed benzodiazepine compounds and a pharmaceutically acceptable carrier. This protects not only the active ingredient but also its delivery as a medication. Method of Treatment Claims: These claims protect the use of the claimed compounds for treating specific medical conditions, primarily anxiety. This can include claims for methods of inducing a calming effect or treating symptoms associated with anxiety disorders. The precise wording and scope of these claims are critical for determining infringement and for assessing the patent's commercial value. Any compound or method that falls within the literal scope of these claims, without prior art anticipation, could be considered infringing. What is the Scope of Protection Afforded by U.S. Patent 4,628,051? The scope of protection for U.S. Patent 4,628,051 is defined by the patent's claims. It encompasses: The Novel Chemical Entities: The patent grants exclusive rights to make, use, sell, offer for sale, and import the specific chemical compounds falling within the structural definition of Claim 1 and its dependent claims. This includes any stereoisomers, enantiomers, or diastereomers that meet the claim limitations. Pharmaceutical Compositions: The patent also covers any pharmaceutical formulation containing one or more of the claimed compounds, along with suitable excipients. This prevents competitors from creating and marketing drug products containing these active ingredients, even if they did not synthesize the active ingredient themselves. Methods of Treatment: The patent provides protection for the therapeutic use of the claimed compounds in treating conditions such as anxiety. This means that even if a competitor manufactures the compound for a non-infringing purpose, they could infringe if they market it for anxiety treatment, or if physicians prescribe it for anxiety treatment. The effective term of this patent would have been 17 years from its issue date. Patent 4,628,051 was filed on August 15, 1984, and issued on August 20, 1986. Therefore, its statutory term expired on August 20, 2003. However, patent term adjustments (PTA) or patent term extensions (PTE) could have potentially extended this period if applicable under U.S. patent law at the time. What is the Prior Art Landscape for U.S. Patent 4,628,051? The prior art landscape is crucial for evaluating the novelty and inventiveness of the claimed compounds and methods in U.S. Patent 4,628,051. Prior art includes any publicly available information or patented invention that predates the patent's filing date. The benzodiazepine class of drugs was well-established by the mid-1980s, with numerous compounds already on the market for their anxiolytic, sedative, hypnotic, anticonvulsant, and muscle relaxant properties. Key examples of prior art benzodiazepines include: Diazepam (Valium): Patented in the 1950s. Chlordiazepoxide (Librium): One of the earliest benzodiazepines. Alprazolam (Xanax): Introduced in the late 1970s. Lorazepam (Ativan): Another widely used anxiolytic. These prior art examples demonstrate a significant body of knowledge regarding the synthesis and pharmacological effects of benzodiazepines. Key aspects of the prior art relevant to Patent 4,628,051 would include: Known Benzodiazepine Structures: A vast array of benzodiazepine structures with varying substitutions were known. Established Synthetic Routes: Standard chemical reactions for synthesizing the benzodiazepine core and attaching side chains were well-documented. Known Pharmacological Activity: The general anxiolytic and sedative effects of the benzodiazepine class were widely recognized. For U.S. Patent 4,628,051 to be considered valid, the claimed compounds had to be novel and non-obvious in light of this existing knowledge. This would mean that the specific structural modifications introduced in Patent 4,628,051, along with their resulting pharmacological profile (e.g., improved efficacy, reduced side effects, unique mechanism of action), had to be demonstrably different and not predictable from the prior art. The patent examiner would have conducted a thorough search of chemical literature, existing patents, and scientific publications to assess novelty and inventiveness. If the claimed compounds or methods were found to be disclosed or suggested in the prior art, the patent could have been rejected or its claims significantly narrowed. What was the Commercialization and Market Impact of Compounds Covered by U.S. Patent 4,628,051? The commercialization and market impact of compounds specifically covered by U.S. Patent 4,628,051 are not readily apparent from public databases. While the patent was issued to Hoffmann-La Roche, Inc., a major pharmaceutical company, it does not automatically guarantee successful development and market launch of all claimed compounds. Factors influencing commercialization: Clinical Trial Success: Novel compounds must undergo rigorous preclinical and clinical trials to demonstrate safety and efficacy. Many promising drug candidates fail during this process. Regulatory Approval: Successful clinical trials are followed by a lengthy and complex regulatory approval process by agencies like the U.S. Food and Drug Administration (FDA). Therapeutic Differentiation: Even if approved, a drug must offer a significant advantage over existing treatments to gain market share. Given the mature market for anxiolytics, introducing a new benzodiazepine would have required demonstrating a substantial improvement in efficacy, safety, or a unique patient population benefit. Patent Expiration: As noted, the statutory term for U.S. Patent 4,628,051 expired in 2003. This means that even if a drug was successfully developed and launched, it would have faced generic competition shortly after the patent's expiry (or earlier if generic companies challenged patent validity or sought regulatory exclusivities). Without specific product names linked to this patent, it is difficult to quantify its market impact. Many patents, particularly those covering broad classes of compounds, may protect research compounds, early-stage candidates, or compounds that ultimately do not prove commercially viable. However, the patent reflects Hoffmann-La Roche's R&D activities in the benzodiazepine space during the 1980s, a period of significant innovation and market dominance for this drug class. The intellectual property secured by this patent would have provided a window of exclusivity for any successful drug candidate derived from it during its term. What is the Current Status and Potential for Future Development Related to U.S. Patent 4,628,051? As of the current date, U.S. Patent 4,628,051 has expired. Its statutory expiration date was August 20, 2003. This means that the patent no longer provides exclusive rights to Hoffmann-La Roche, Inc. or its assignees for the claimed compounds or methods of treatment. Implications of Patent Expiration: Generic Competition: Compounds covered by the patent can now be manufactured, sold, and used by any entity without infringing the expired patent. This typically leads to the availability of generic versions of any successful drug developed under the patent. Freedom to Operate: Researchers and companies are free to investigate and develop compounds structurally similar or identical to those claimed in the patent, or to use methods of treatment covered by the patent, for new applications or in combination with other therapies, without seeking licenses from the original patent holder. No New Patent Protection for Original Claims: No new patent protection can be obtained for the subject matter that was validly claimed in U.S. Patent 4,628,051. Potential for Future Development: While the original patent has expired, there could be indirect future development related to the technologies or compounds disclosed within. New Patent Filings: Hoffmann-La Roche, or other entities, could have filed new patents on improvements, new formulations, new uses, or novel derivatives of the compounds disclosed in Patent 4,628,051 that meet the criteria for patentability (novelty, non-obviousness, utility) and were developed after the original patent's filing date. These would be distinct from the expired patent. Repurposing or New Indications: The compounds disclosed in the patent, or those structurally related to them, might be explored for new therapeutic indications beyond anxiety, potentially leading to new patent filings for these novel uses. Research Tools: The chemical structures and synthesis methods described in the patent might serve as foundational knowledge or starting points for academic or industrial research into related chemical scaffolds or biological targets. Generics Market: The primary "development" related to expired patents is the generic pharmaceutical market, where companies develop bioequivalent versions of previously patented drugs. In summary, the direct patent protection afforded by U.S. Patent 4,628,051 has concluded. Any ongoing or future commercial activity related to the specific compounds and methods claimed in this patent would be in the public domain, subject only to any other valid intellectual property rights or regulatory requirements. Key Takeaways U.S. Patent 4,628,051 protected a class of 1-alkoxy-2-hydroxyalkyl-benzodiazepine compounds and their use in treating anxiety. The patent claims covered the chemical compounds, pharmaceutical compositions, and methods of treatment. The patent's statutory term expired on August 20, 2003, rendering its claims public. The prior art landscape for benzodiazepines was extensive by the mid-1980s, necessitating novel and non-obvious advancements for patentability. The commercial success and market impact of compounds specifically covered by this expired patent are not publicly detailed, indicating potential non-commercialization or limited market entry before patent expiry. Future development related to the patent's subject matter would involve new patentable inventions, such as novel derivatives, formulations, or uses, as the original patent protection has lapsed. Frequently Asked Questions Can a company legally manufacture and sell a drug that was covered by U.S. Patent 4,628,051 today? Yes, provided that the patent has expired and no other valid patents or regulatory exclusivities apply to that specific drug. U.S. Patent 4,628,051 expired in 2003. Does the expiration of U.S. Patent 4,628,051 mean that all benzodiazepine drugs are now off-patent? No, the expiration of this specific patent only pertains to the claims made within U.S. Patent 4,628,051. Many other benzodiazepine drugs are protected by different, potentially still active, patents. What is the difference between a patent and a drug's regulatory approval? A patent grants exclusive rights to an invention for a limited time. Regulatory approval, such as from the FDA, permits a drug to be marketed to the public after demonstrating safety and efficacy. A drug can be patented but not approved, or approved but not patented (if patents have expired). If a company develops a new use for a compound disclosed in U.S. Patent 4,628,051, can they patent this new use? Yes, a new and non-obvious use for a known compound can be patentable, provided it meets all patentability requirements (novelty, non-obviousness, utility) and was not already disclosed or claimed in the expired patent. What is the role of a patent attorney or agent in relation to expired patents like U.S. Patent 4,628,051? Patent attorneys or agents can advise on patentability of new inventions related to expired patent subject matter, conduct freedom-to-operate analyses to ensure new products do not infringe existing patents, and assist in patent litigation if necessary, even for expired patents in certain contexts (e.g., as prior art). Citations [1] Hoffmann-La Roche, Inc. (1986). 1-Alkoxy-2-hydroxyalkyl-benzodiazepines. U.S. Patent 4,628,051. Washington, DC: U.S. Patent and Trademark Office. More… ↓ ⤷ Start Trial

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Details for Patent: 4,628,051

Summary for Patent: 4,628,051