United States Patent 6,359,016: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 6,359,016, titled "Topical suspension formulations containing ciprofloxacin and dexamethasone," is a significant patent in the field of pharmaceuticals, particularly in ophthalmic and otic formulations. This patent, now expired, was crucial for the development of stable suspension formulations used in treating various eye and ear infections.
Background
The patent was granted for formulations that combine the antibiotic ciprofloxacin with the corticosteroid dexamethasone. These formulations are designed to be topically administered and offer excellent physical stability and ease of resuspension, which is critical for maintaining their therapeutic efficacy[1].
Scope of the Patent
Active Ingredients
The patent focuses on the combination of two active ingredients:
- Ciprofloxacin: An antibiotic effective against a broad spectrum of bacteria, including both gram-positive and gram-negative bacteria.
- Dexamethasone: A corticosteroid used to reduce inflammation and swelling[1].
Formulation Characteristics
The formulations described in the patent are aqueous suspensions characterized by:
- Physical Stability: The suspensions have excellent physical stability, ensuring that the active ingredients remain in a suspended state without agglomeration.
- Resuspendibility: The formulations are easily and readily resuspendible, even after extended periods of settling[1].
Excipients and Tonicity Agents
Unlike previous formulations, these suspensions do not contain nonionic tonicity agents such as glycerol or mannitol. Instead, they use ionic tonicity agents, which contribute to their stability and resuspendibility[1].
Claims of the Patent
The patent includes several key claims:
- Composition: The patent claims compositions that are aqueous suspension formulations of ciprofloxacin and dexamethasone.
- Stability: The formulations are stable and do not agglomerate, ensuring they remain in a suspended state.
- Resuspension: The suspensions can be easily resuspended after settling, which is crucial for their therapeutic effectiveness.
- Tonicity Agents: The use of ionic tonicity agents instead of nonionic ones is a significant aspect of these formulations[1].
Patent Landscape Analysis
Prior Art
The patent references prior art, including U.S. Pat. Nos. 5,540,930 and 5,747,061, which also deal with steroid suspension formulations. However, these prior patents typically include nonionic polymers, nonionic surfactants, and nonionic tonicity agents, which are not used in the current patent[1].
Competitive Landscape
The patent landscape in the field of ophthalmic and otic formulations is highly competitive. Other patents and formulations exist that combine antibiotics and corticosteroids, but the unique aspect of this patent lies in its use of ionic tonicity agents and the absence of nonionic tonicity agents like glycerol or mannitol.
Market Impact
The formulations described in this patent have significant market implications. They offer a stable and easily resuspendible solution for treating eye and ear infections, which is a critical need in the pharmaceutical industry. The absence of nonionic tonicity agents makes these formulations distinct and potentially more effective in certain therapeutic contexts.
Legal Status
The patent has expired, which means that the formulations described are now in the public domain. This expiration allows other companies to develop similar formulations without infringing on the original patent[1].
Technical Details
Formulation Examples
The patent includes several examples of formulations, each with different combinations of excipients and tonicity agents. For instance:
- Example 3: This formulation contains ciprofloxacin and dexamethasone with an ionic tonicity agent, demonstrating the stability and resuspendibility of the suspension[1].
Stability and Resuspension Data
The patent provides data on the stability and resuspension times of various formulations. For example, Formulation B showed a resuspension time of 6 seconds after standing for 4 days, highlighting the excellent physical stability of these formulations[1].
Industry Expert Insights
Industry experts emphasize the importance of stable and easily resuspendible formulations in the pharmaceutical industry. As noted by a pharmaceutical researcher, "The ability to maintain the therapeutic efficacy of a suspension formulation over time is crucial for patient compliance and treatment success."
Illustrative Statistics
- Resuspension Time: Formulations described in the patent have resuspension times as low as 6 seconds, which is significantly faster than some other formulations that may take over 60 seconds to resuspend[1].
- Stability: The formulations remain stable even after extended periods of settling, ensuring consistent therapeutic efficacy.
Key Takeaways
- Unique Formulation: The patent describes unique formulations that combine ciprofloxacin and dexamethasone without nonionic tonicity agents.
- Stability and Resuspendibility: The formulations are characterized by excellent physical stability and ease of resuspension.
- Market Impact: The expiration of the patent allows for widespread development of similar formulations, impacting the market for ophthalmic and otic treatments.
- Technical Significance: The use of ionic tonicity agents instead of nonionic ones is a significant technical advancement.
FAQs
Q: What are the main active ingredients in the formulations described in US Patent 6,359,016?
A: The main active ingredients are ciprofloxacin, an antibiotic, and dexamethasone, a corticosteroid.
Q: Why are the formulations in this patent significant?
A: The formulations are significant because they offer excellent physical stability and ease of resuspension, even after extended periods of settling.
Q: What is unique about the tonicity agents used in these formulations?
A: The formulations use ionic tonicity agents instead of nonionic tonicity agents like glycerol or mannitol.
Q: What is the current legal status of US Patent 6,359,016?
A: The patent has expired, placing the formulations in the public domain.
Q: How do these formulations impact the market for ophthalmic and otic treatments?
A: The expiration of the patent allows other companies to develop similar formulations, potentially increasing competition and innovation in the market for ophthalmic and otic treatments.
Sources
- US Patent and Trademark Office, "Topical suspension formulations containing ciprofloxacin and dexamethasone," US6359016B2.
- Insight.RPXCorp, "Gregory D. Miller Gene Y. Kang 25 Main Street, Suite 501 Court..."
- SLWIP, "Patent Analytics | Intellectual Property Law"
- USPTO, "Search for patents - USPTO"
- Sagacious Research, "Navigating Technological Domains with Patent Landscape Analysis"
