Detailed Analysis of the Scope and Claims of United States Patent 7,175,855
Introduction
United States Patent 7,175,855, titled "Ziprasidone suspension," is a patent that covers a specific composition and method related to the antipsychotic medication ziprasidone. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background of Ziprasidone
Ziprasidone is an antipsychotic medication used primarily to treat schizophrenia and bipolar disorder. It is known for its efficacy and relatively favorable side effect profile compared to other antipsychotics. The development of a suspension formulation is significant because it can improve the drug's bioavailability and patient compliance, especially for those who have difficulty swallowing tablets or capsules.
Patent Overview
Inventors and Assignees
The patent was granted to Pfizer Inc., with the inventors listed as Robert E. Johnson, Robert J. Dunn, and others. This indicates that the invention was developed within Pfizer's research and development division.
Filing and Grant Dates
The patent application was filed on October 25, 2002, and the patent was granted on February 13, 2007. This timeline is typical for the patent prosecution process, which often takes several years.
Scope of the Patent
Claims
The patent includes several claims that define the scope of the invention. Here are some key claims:
- Claim 1: A composition of matter which is a suspension comprising ziprasidone free base or a difficult to wet salt thereof, and at least one suspending agent.
- Claim 2: The composition of claim 1, wherein the suspending agent is selected from the group consisting of xanthan gum, carrageenan, and pectin.
- Claim 3: The composition of claim 1, further comprising at least one wetting agent.
These claims specify the essential components of the ziprasidone suspension, including the active ingredient (ziprasidone free base or its salt), suspending agents, and optional wetting agents[5].
Description of the Invention
The patent describes a suspension formulation of ziprasidone that is designed to improve the drug's stability and bioavailability. The formulation includes ziprasidone free base or a salt thereof, along with suspending agents such as xanthan gum, carrageenan, or pectin. The inclusion of wetting agents is also mentioned to enhance the wettability of the ziprasidone particles, which can be difficult to wet due to their hydrophobic nature.
Patent Landscape
Technology Field
The patent falls under the "Drugs and Medical Instruments" field, one of the six broad technology fields categorized by the USPTO. This field has seen significant changes in patent allowance rates over the years, with a notable decline in allowance rates for applications filed between 1996 and 2005[1].
Allowance Rates
The overall allowance rate for utility patent applications in the "Drugs and Medical Instruments" field has decreased substantially. For applications filed between 1996 and 2005, the progenitor allowance rate (the proportion of applications allowed without any continuation procedure) was lower compared to other fields. This trend suggests that the USPTO has become more stringent in granting patents in this field, possibly due to increased scrutiny and the complexity of medical inventions[1].
Related Patents and Continuation Applications
The USPTO's internal databases and the Patent Application and Information Retrieval (PAIR) system can provide insights into related patents and continuation applications. For instance, the Patent Claims Research Dataset can be used to analyze the scope and dependency relationships between claims in related patents and applications[3].
Search and Examination Process
Public Search Tools
To understand the prior art and the patent landscape surrounding US 7,175,855, one can use the USPTO's Public Search tool, which replaced legacy search tools like PubEast and PubWest. This tool provides enhanced access to prior art and allows users to search for existing patents and published patent applications[4].
Global Dossier and Common Citation Document
Tools like the Global Dossier and the Common Citation Document (CCD) can be useful in identifying related applications and prior art cited by other IP offices. These tools help in visualizing the search results for the same invention produced by several offices on a single page[4].
Practical Implications
Commercial Use and Licensing
The patent grants Pfizer Inc. exclusive rights to manufacture, use, and sell the ziprasidone suspension formulation. This exclusivity can impact the market by limiting competition and allowing Pfizer to set prices and distribution channels. Licensing agreements may also be negotiated with other pharmaceutical companies to expand the reach of the product.
Litigation and Enforcement
Given the specificity of the claims, any potential infringers would need to ensure their formulations do not infringe on Pfizer's patent. The patent's validity and enforcement can be crucial in protecting Pfizer's intellectual property rights and market share.
Key Takeaways
- Patent Scope: The patent covers a specific suspension formulation of ziprasidone, including the use of suspending and wetting agents.
- Claims: The claims define the essential components and their roles in the formulation.
- Patent Landscape: The patent falls within the "Drugs and Medical Instruments" field, which has seen declining allowance rates.
- Search and Examination: Public search tools and databases like Global Dossier and CCD are essential for understanding prior art and related applications.
- Practical Implications: The patent grants exclusive rights to Pfizer, impacting market competition and potential licensing agreements.
FAQs
Q: What is the primary invention described in US Patent 7,175,855?
A: The primary invention is a suspension formulation of the antipsychotic medication ziprasidone, including specific suspending and wetting agents.
Q: Who are the inventors and assignees of the patent?
A: The inventors include Robert E. Johnson, Robert J. Dunn, and others, with Pfizer Inc. as the assignee.
Q: What is the significance of the suspending agents in the formulation?
A: The suspending agents, such as xanthan gum, carrageenan, or pectin, help maintain the stability of the ziprasidone suspension.
Q: How does the patent landscape affect the allowance rate for similar patents?
A: The allowance rate for patents in the "Drugs and Medical Instruments" field has decreased over time, indicating a more stringent examination process.
Q: What tools can be used to search for related patents and prior art?
A: Tools such as the USPTO's Public Search, Global Dossier, and Common Citation Document can be used to search for related patents and prior art.
Sources
- Carley, M., Hegde, D., & Marco, A. (2015). What Is the Probability of Receiving a US Patent? Yale Journal of Law & Technology, 17, 203-236.
- Administrative Conference of the United States. (2022). U.S. Patent Small Claims Court.
- United States Patent and Trademark Office. (2017). Patent Claims Research Dataset.
- United States Patent and Trademark Office. (2018). Search for patents.
- Pfizer Inc. (2007). Ziprasidone suspension. US Patent 7,175,855 B1.
