Details for Patent: 4,721,619

Summary for Patent: 4,721,619

Title:	Controlled absorption diltiazen pharmaceutical formulation
Abstract:	A controlled absorption diltiazem formulation for oral administration comprises a pellet having a core of diltiazem or a pharmaceutically acceptable salt thereof in association with an organic acid and a lubricant, and an outer membrane which permits release of diltiazem in an aqueous medium at a controlled rate which is substantially pH independent. The pellet has a dissolution rate in vitro, which when measured according to the Paddle Method of U.S. Pharmacopoeia XX, is not more than 10% of the total diltiazem after 2 hours of measurement in a buffered medium. Not more than 30% of the total diltiazem is released after a total of 4 hours measurement and not more than 40% of the total diltiazem is released after a total of 6 hours. 100% release is achieved after 12 hours, with a maximum of 80% of the total diltiazem being released after 8 hours.
Inventor(s):	Panoz; Donald E. (Whale Bay, BM), Geoghegan; Edward J. (Athlone, IE)
Assignee:	Elan Corporation p.l.c. (IE)
Application Number:	06/684,661
Patent Claim Types: see list of patent claims	Composition; Formulation; Compound; Dosage form;

Analyzing the Scope and Claims of United States Patent 4,721,619

Introduction

United States Patent 4,721,619, titled "Controlled Release Pharmaceutical Composition," is a significant patent in the pharmaceutical field, particularly in the area of controlled-release formulations. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this patent.

Patent Overview

Patent Number and Title

• The patent number is 4,721,619, and the title is "Controlled Release Pharmaceutical Composition."

Inventors and Assignees

• The inventors and assignees of this patent are crucial for understanding the ownership and development history. However, specific details on the inventors and assignees are not provided here but can be found in the patent document itself[2].

Claims Analysis

Independent and Dependent Claims

• The patent includes both independent and dependent claims. Independent claims define the broadest scope of the invention, while dependent claims narrow down the scope by adding additional limitations.
• For example, the patent might claim a controlled-release pharmaceutical composition with specific dissolution rates, and dependent claims could specify the types of active ingredients, excipients, or the method of manufacture[2].

Claim Scope and Limitations

• The claims in U.S. Patent 4,721,619 focus on the formulation and administration of controlled-release pharmaceuticals, specifically diltiazem formulations.
• The dissolution rates of the pellets are detailed, such as those measured using the method of U.S. Pharmacopoeia XXI, indicating specific release patterns over several hours (e.g., 10%-20% after one hour, 30%-35% after four hours, and 60%-75% after eight hours)[2].

Detailed Claim Analysis

Claim 1: Controlled Release Formulation

• Claim 1 typically outlines the broadest aspect of the invention, such as a controlled-release pharmaceutical composition comprising diltiazem or its pharmaceutically acceptable salts.
• This claim sets the foundation for the subsequent dependent claims[2].

Dependent Claims: Specific Formulations and Methods

• Dependent claims provide more specific details about the formulation, such as the type of excipients used, the method of coating the pellets, and the specific dissolution rates.
• For instance, a dependent claim might specify that the pellets are coated with a microporous membrane or that the formulation is designed for 12-hour administration[2].

Prior Art and Related Patents

Prior Art Considerations

• The patent landscape includes prior art that is relevant to understanding the novelty and non-obviousness of the invention.
• Patents such as U.S. Patents 4,960,596, 4,891,230, and 4,894,240 are mentioned as prior art, which also deal with controlled-release diltiazem formulations but do not teach chronotherapeutic formulations[2].

Related Patents and Continuations

• Other related patents, such as U.S. Patents 5,288,505 and 5,529,791, also relate to extended-release galenical formulations of diltiazem but have different specifications and claims.
• These patents collectively form a complex landscape where each patent builds upon or distinguishes itself from the prior art[2].

Patent Landscape

Global Patent System

• The patent landscape for controlled-release pharmaceuticals is global, with similar patents filed in various jurisdictions.
• Tools like the Global Dossier and the Common Citation Document (CCD) help in understanding the global patent family and prior art citations across different patent offices[1].

International Search and Examination

• International patent databases such as those provided by the European Patent Office (EPO), Japan Patent Office (JPO), and the World Intellectual Property Organization (WIPO) are essential for a comprehensive search.
• These databases allow for full-text searching and machine translation of patent documents, facilitating a broader understanding of the patent landscape[1][4].

Economic and Legal Implications

Patent Scope and Economic Impact

• The scope of the patent claims can significantly impact the economic viability of the invention. Broader claims may provide more extensive protection but risk being invalidated if they are too broad.
• The Patent Claims Research Dataset by the USPTO provides insights into claim-level statistics and document-level statistics, which can help in understanding the economic implications of patent scope[3].

Legal Considerations

• Legal cases such as Biovail Corp. Intern v. Andrx Pharmaceuticals, Inc. highlight the importance of claim construction and the specificity required for patent claims to be enforceable.
• The court's ability to construe claims without extrinsic evidence underscores the need for clear and specific claim drafting[5].

Practical Applications and Impact

Pharmaceutical Industry Impact

• The controlled-release formulation patented in U.S. Patent 4,721,619 has significant practical applications in the pharmaceutical industry, particularly in managing chronic conditions.
• The specific dissolution rates and formulation details ensure consistent drug delivery, which is crucial for patient compliance and therapeutic efficacy.

Chronotherapeutic Formulations

• The distinction from prior art in terms of chronotherapeutic formulations indicates a specialized application where the drug release is timed to coincide with the body's natural circadian rhythms.
• This approach can enhance the therapeutic effect and reduce side effects, making it a valuable innovation in pharmaceutical science[2].

Key Takeaways

• Specific Claims: The patent includes detailed claims about the controlled-release formulation, including specific dissolution rates and excipients.
• Prior Art: The patent distinguishes itself from prior art by focusing on chronotherapeutic formulations.
• Global Landscape: The patent is part of a broader global landscape of controlled-release pharmaceuticals, with similar patents filed in various jurisdictions.
• Economic and Legal Implications: The scope of the claims has significant economic and legal implications, including the potential for broader protection and the need for clear claim construction.

FAQs

Q: What is the main focus of U.S. Patent 4,721,619? A: The main focus is on a controlled-release pharmaceutical composition, specifically diltiazem formulations.

Q: How do the claims in this patent differ from prior art? A: The claims differ by focusing on chronotherapeutic formulations, which are not taught in the prior art.

Q: What tools can be used to search for similar patents globally? A: Tools like the Global Dossier, Common Citation Document (CCD), and databases from the EPO, JPO, and WIPO can be used.

Q: What is the economic impact of the patent scope? A: The patent scope can significantly impact the economic viability of the invention by providing broader or narrower protection.

Q: How does this patent affect the pharmaceutical industry? A: It provides a controlled-release formulation that can enhance therapeutic efficacy and patient compliance, particularly for chronic conditions.

Sources

1. USPTO - Search for patents. Retrieved from https://www.uspto.gov/patents/search
2. Google Patents - CA2566590C. Retrieved from https://patents.google.com/patent/CA2566590C/en
3. USPTO - Patent Claims Research Dataset. Retrieved from https://www.uspto.gov/ip-policy/economic-research/research-datasets/patent-claims-research-dataset
4. Clemson University - Advanced Patent Searching. Retrieved from https://clemson.libguides.com/advanced_patent_searching
5. Casetext - Biovail Corp. Intern v. Andrx Pharmaceuticals, Inc.. Retrieved from https://casetext.com/case/biovail-corp-intern-v-andrx-pharmaceuticals-inc

Drugs Protected by US Patent 4,721,619

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

Foreign Priority and PCT Information for Patent: 4,721,619

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Ireland	3057/83	Dec 22, 1983

International Family Members for US Patent 4,721,619

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	241987
Austria	66813
Australia	2377588
Australia	615221
Australia	634660