Details for Patent: 5,028,621

Summary for Patent: 5,028,621

Title:	Drugs comprising porphyrins
Abstract:	To obtain tumor-selective, photosensitizing drugs useful in the localization of neoplastic tissue and treatment of abnormal neoplastic tissue such as tumors, one of two methods is used. In the first method, a hydrolyzed mixture of the products of reaction of hematoporphyrin with acetic acid and sulfuric acid is cycled through a microporous membrane system to exclude low molecular weight products. In the second method, drugs are synthesized or derived from other pyrrole compounds. The drugs (1) include two covalently bound groups, each with four rings, some of which are pyrroles such as phlorins, porphyrins, chlorins, substituted pyrroles, substituted chlorins or substituted phlorins, each group being arranged in a ring structure, connected covalently to another group and have a triplet energy state above 37.5 kilocalories per mole; (2) are soluble in water, forming an aggregate of over 10,000 molecular weight in water and have an affinity for each other compared to serum protein such that 10 to 100 percent remain self aggregated in serum protein; and (3) are lipophyllic and able to disaggregate and attach to cell plasma, nuclear membrane, mitochondria, lysosomes and tissue. The drug obtained by the first method has an empirical formula of approximately C.sub.68 H.sub.70 N.sub.8 O.sub.11 or C.sub.68 H.sub.66 N.sub.8 O.sub.11 Na.sub.4. Neoplastic tissue retains the drug after it has cleared normal tissues and illumination results in necrosis. Moreover, other photosensitizing materials may be combined with a carrier that enters undesirable tissues and cells of the reticular endothelial system such as macrophages. These photosensitizing materials: (1) must have a triplet energy state above 3.5 kilocalories per mole; (2) cannot be easily oxidized; and (3) not physically quench any required energy state. Preferably, this photosensitizing material should be lipophlic.
Inventor(s):	Dougherty; Thomas J. (Grand Island, NY), Potter; William R. (Grand Island, NY), Weishaupt; Kenneth R. (Sloan, NY)
Assignee:	Health Research, Inc. (Buffalo, NY)
Application Number:	07/352,774
Patent Claim Types: see list of patent claims	Composition; Compound;

Understanding the Scope and Claims of United States Patent 5,028,621: A Detailed Analysis

Introduction

United States Patent 5,028,621, though not directly provided in the sources, can be analyzed using general principles of patent scope, claims, and the broader patent landscape. Here, we will delve into the key components that define a patent's scope and claims, and how these elements impact the patent's significance and protection.

What is a Patent?

A patent is a form of intellectual property that grants the owner the legal right to exclude others from making, using, selling, and importing an invention for a certain period of time, usually 20 years from the filing date.

Patent Scope

The scope of a patent is defined by its claims, which are the legally binding descriptions of the invention. The broader the claims, the more protection the patent offers against potential infringers.

Measuring Patent Scope

Research indicates that the breadth of a patent’s scope can be measured in several ways:

• Number of Words in the First Claim: Patents with shorter claims tend to have broader scope because fewer conditions need to be met for infringement[3].
• Number of Patent Classes: Contrary to common assumptions, the number of patent classes assigned to a patent is often negatively correlated with patent scope[3].
• Number of Claims: While more claims may cover more technology, they do not necessarily make the patent broader. Independent claims define the legal right to exclude, and dependent claims are narrower fallback positions[3].

Patent Claims

Claims are the heart of a patent, outlining what the inventor considers to be their invention.

Independent Claims

These are the broadest claims in a patent and define the legal right to exclude others from making, using, or selling the invention. Independent claims are crucial because they set the boundaries of what is protected[3].

Dependent Claims

Dependent claims are narrower and build upon independent claims. They serve as fallback positions in case an independent claim is invalidated. Each dependent claim must be narrower than the independent claim it depends on[3].

Patent Landscape

The patent landscape includes all existing patents and patent applications in a particular field of technology.

Technology Centers and Art Units

The USPTO organizes patents into eight technology centers, each focusing on broad areas of technology, such as Biotechnology, Chemical and Materials Engineering, and Semiconductors. These centers are further divided into art units that focus on more granular technologies[3].

Analyzing United States Patent 5,028,621

Background and Invention

To analyze the scope and claims of a specific patent like 5,028,621, one would need to review the patent document itself. Here are some general steps:

• Read the Background Section: Understand the problem the invention solves and the prior art.
• Examine the Claims: Identify the independent and dependent claims. Independent claims will give you the broadest definition of the invention, while dependent claims will provide additional details and narrower aspects[3].

Claim Construction

• Independent Claims: Look for the broadest claims that define the invention. These claims should be concise yet comprehensive.
• Dependent Claims: Analyze how the dependent claims build upon the independent claims, adding specific details or limitations.

Prior Art and Novelty

• Prior Art: Review the prior art cited in the patent to understand what was known before the invention.
• Novelty: Determine how the invention differs from the prior art and what makes it novel and non-obvious.

Impact on the Patent Landscape

Competitor Analysis

A broad patent with well-crafted claims can significantly impact competitors by making it harder for them to design around the invention. Broad patents offer more protection against infringers because they are harder to circumvent[3].

Licensing and Litigation

The scope and claims of a patent can influence licensing agreements and litigation outcomes. A patent with broad and well-defined claims is more likely to be valuable in licensing negotiations and more defensible in court.

Key Takeaways

• Patent Scope: Defined by the claims, particularly the independent claims.
• Claim Structure: Independent claims are broad, while dependent claims are narrower.
• Patent Landscape: Understanding the broader technological area and existing patents is crucial.
• Competitor Impact: Broad patents with clear claims can significantly limit competitors.
• Licensing and Litigation: The scope and claims of a patent are critical in licensing and litigation.

FAQs

Q: What defines the scope of a patent? A: The scope of a patent is defined by its claims, especially the independent claims.

Q: How are patent claims structured? A: Patents have independent claims that define the broadest aspects of the invention and dependent claims that are narrower and build upon the independent claims.

Q: Why is the number of words in the first claim important? A: The number of words in the first claim can indicate the breadth of the patent scope; fewer words generally mean broader scope.

Q: How does the USPTO organize patents? A: The USPTO organizes patents into eight technology centers, each further divided into art units focusing on more specific technologies.

Q: What is the significance of prior art in patent analysis? A: Prior art helps in understanding what was known before the invention and how the new invention differs from existing knowledge.

Sources

1. US5756541A - Vision through photodynamic therapy of the eye - Google Patents
2. EP1539067A1 - Combined photocoagulation and ... - Google Patents
3. The Ways We've been Measuring Patent Scope are Wrong: - Boston University Law
4. Patent and Trademark Office Notices - USPTO
5. United States Patent (19) - googleapis.com

Drugs Protected by US Patent 5,028,621

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent 5,028,621

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	53204
Australia	2032283
Australia	4246185
Australia	581840
Australia	588806