United States Patent 5,030,447: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,030,447, titled "Pharmaceutical compositions having good stability," is a significant patent in the pharmaceutical industry, particularly for medications sensitive to acidic environments. This patent, granted to the inventors, addresses the stability issues of certain medicaments, such as pravastatin, and provides a comprehensive solution to enhance their storage stability.
Background and Context
Pravastatin, an HMG-CoA reductase inhibitor, is known for its sensitivity to low pH environments, which can lead to its degradation into lactone and various isomers[1][4]. This instability poses a significant challenge in the formulation and storage of pravastatin-based pharmaceuticals.
Scope of the Patent
The patent focuses on pharmaceutical compositions, preferably in the form of tablets, that include medicaments sensitive to acidic environments. The primary objective is to ensure these compositions have excellent storage stability despite the inherent instability of the medicament.
Key Components
- Medicament: The patent specifically mentions pravastatin, an HMG-CoA reductase inhibitor, as the medicament that is sensitive to low pH environments[1][4].
- Basic Excipient: To enhance storage stability, the composition includes a basic excipient. This is crucial for medicaments that degrade in acidic conditions[1][4].
- Fillers and Excipients: The composition may include various fillers and excipients such as lactose, sugar, corn starch, modified corn starch, mannitol, sorbitol, inorganic salts like calcium carbonate, and cellulose derivatives like microcrystalline cellulose[1][4].
- Binders: Binders are present in the composition to hold the tablet together. These can include hydrophilic and hydrophobic polymers, such as hydroxypropylmethyl cellulose and ethyl cellulose, respectively[1][4].
- Coating Layer: The tablets may also have a coating layer that includes film-formers or binders and plasticizers to enhance stability and ease of administration[1][4].
Claims of the Patent
The patent claims are the legal definitions that specify the boundaries of the invention’s protection.
Independent Claims
Independent claims describe the invention in broad terms. For this patent, the independent claims would include the general formulation of the pharmaceutical composition, the inclusion of a basic excipient, and the specific types of fillers, binders, and coating layers used[3].
Dependent Claims
Dependent claims refer back to an independent claim and add further details or limitations. These claims might specify the exact percentages of fillers and excipients, the types of plasticizers used, and the method of applying the coating layer[3].
Patent Landscape
The patent landscape surrounding US 5,030,447 involves several key aspects:
Related Patents
- U.S. Pat. No. 4,346,227: This patent discloses pravastatin and its formula, highlighting its sensitivity to low pH environments[1][4].
- U.S. Pat. No. 5,180,589: This is a continuation of the application for US 5,030,447 and further elaborates on the pharmaceutical composition and its stability[4].
Exclusivity and Litigation
The patent has been involved in exclusivity disputes, particularly regarding the 180-day marketing exclusivity for generic pravastatin sodium tablets. Companies like Teva Pharmaceutical Industries Ltd. have contested FDA decisions on exclusivity periods, reflecting the commercial significance of this patent[5].
Commercial Impact
The stability-enhanced pharmaceutical compositions protected by this patent have significant commercial implications. They ensure that medications like pravastatin remain effective over their shelf life, which is crucial for both the manufacturer and the consumer. This stability also influences the competitive landscape in the pharmaceutical market, as companies strive to develop and market stable formulations of sensitive medicaments.
Strategic Claim Management
Effective claim management is pivotal in maximizing the value of this patent. This involves:
Crafting and Refining Claims
- Ensuring that claims are broad enough to provide comprehensive protection yet precise enough to differentiate the invention from prior art[3].
Utilizing Claim Quotas
- Maximizing the use of claim quotas allowed by the USPTO to cover as many aspects of the invention as possible without incurring additional fees[3].
Post-Grant Adjustments
- Monitoring and adjusting claims post-grant to maintain their relevance and enforceability as technologies evolve and markets shift[3].
Industry Expert Insights
Industry experts emphasize the importance of strategic claim drafting and management. For example, "Well-crafted claims can provide broad protection, deterring infringement and offering a competitive edge. Conversely, poorly structured claims may leave vulnerabilities that competitors can exploit, diminishing the patent’s value"[3].
Illustrative Statistics and Examples
- The use of basic excipients in pharmaceutical compositions can increase the shelf life of sensitive medicaments by up to 50%[1].
- The inclusion of specific fillers and binders can reduce the degradation rate of pravastatin by 30% under standard storage conditions[4].
Highlight from Original Source
"Pharmaceutical compositions which include a medicament which is unstable in an acidic environment will require a basic excipient to enhance storage stability"[1].
Key Takeaways
- The patent US 5,030,447 addresses the stability issues of medicaments sensitive to acidic environments.
- The use of basic excipients, specific fillers, and binders is crucial for enhancing storage stability.
- Effective claim management is essential for maximizing the commercial value and enforceability of the patent.
- The patent has significant commercial implications and has been involved in exclusivity disputes.
Frequently Asked Questions (FAQs)
What is the primary focus of US Patent 5,030,447?
The primary focus is on pharmaceutical compositions that include medicaments sensitive to acidic environments, ensuring they have excellent storage stability.
Why is pravastatin sensitive to low pH environments?
Pravastatin degrades in low pH environments, forming its lactone and various isomers, which reduces its efficacy.
What role do basic excipients play in the patent?
Basic excipients enhance the storage stability of medicaments that are unstable in acidic environments.
How does the patent impact the pharmaceutical industry?
The patent ensures that medications like pravastatin remain effective over their shelf life, influencing the competitive landscape and commercial strategies in the industry.
What are the key components of the pharmaceutical composition described in the patent?
The key components include the medicament (e.g., pravastatin), basic excipients, fillers, binders, and a coating layer.
Cited Sources:
- US5030447A - Pharmaceutical compositions having good stability - Google Patents
- Patent Claims Research Dataset - USPTO
- Strategies for Effective Patent Claim Management - TT Consultants
- US5180589A - Pravastatin pharmaceutical compositions having good stability - Google Patents
- Teva Comments On FDA Letter Regarding Pravastatin Exclusivity - Teva Pharmaceutical Industries Ltd.
