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Patent landscape, scope, and claims: |
Analysis of U.S. Patent 4,166,182: Scope, Claims, and Landscape
U.S. Patent 4,166,182, granted on August 7, 1979, to Schering Corporation, pertains to a method for preparing a specific dosage form of a corticosteroid. The patent claims a process for producing a sustained-release oral dosage form containing triamcinolone acetonide. This involved a unique granular composition suitable for direct compression into tablets. The patent's scope is limited to this specific manufacturing process and the resulting dosage form, not the active pharmaceutical ingredient itself.
What is the core invention claimed in U.S. Patent 4,166,182?
The central claim of U.S. Patent 4,166,182 is the preparation of a sustained-release oral dosage form of triamcinolone acetonide. Specifically, the invention focuses on a method for creating a granular composition of triamcinolone acetonide, which is then directly compressed into tablets. The key innovation lies in the specific formulation and process that allows for sustained release of the corticosteroid when ingested orally.
Claim 1 Analysis
Claim 1, the primary independent claim, defines the core invention:
"A process for preparing a sustained-release oral dosage form of triamcinolone acetonide which comprises providing a granular composition of triamcinolone acetonide and a binder, said composition being suitable for direct compression into tablets, and then directly compressing said composition into tablets." [1]
This claim outlines a two-step process:
- Provision of a granular composition: This involves combining triamcinolone acetonide with a binder to form granules. The patent implies that this granulation step is critical for achieving the desired sustained-release properties and direct compressibility.
- Direct compression: The prepared granules are then compressed directly into tablets. This bypasses traditional wet granulation or roller compaction steps, suggesting an efficiency improvement or a method that preserves the integrity of the active ingredient.
Dependent Claims
Dependent claims refine and add specifics to the core process, further defining the scope:
- Claim 2: Relates to a process wherein the binder is a hydrophilic polymer. This narrows the scope to formulations utilizing specific types of binders known to influence drug release.
- Claim 3: Specifies that the hydrophilic polymer is selected from the group consisting of cellulose derivatives, acrylic acid derivatives, and polyvinyl pyrrolidone. This further restricts the eligible binders.
- Claim 4: Refers to a process where the binder is a methacrylate ester copolymer. This highlights another specific class of polymers.
- Claim 5: Describes a process where the granular composition is prepared by spray drying. This introduces a specific granulation technique.
- Claim 6: Focuses on a process where the granular composition is prepared by fluid bed granulation. This indicates an alternative granulation method.
- Claim 7: Pertains to a process where the granular composition is prepared by agglomeration. This describes another potential method for granule formation.
- Claim 8: Mentions a process where the binder is a methacrylic acid copolymer having an average molecular weight between 50,000 and 150,000. This provides a specific molecular weight range for a particular type of binder.
These dependent claims, while adding specificity, ultimately fall under the umbrella of the process described in Claim 1. They define specific embodiments or preferred aspects of the patented method.
What is the intended therapeutic use of the patented compound?
The patent explicitly states the compound is triamcinolone acetonide. Triamcinolone acetonide is a synthetic corticosteroid with potent anti-inflammatory, immunosuppressive, and anti-allergic properties. In its sustained-release oral dosage form, it would typically be used to treat a variety of inflammatory and allergic conditions where prolonged corticosteroid action is desired. These conditions can include:
- Rheumatoid arthritis and other inflammatory joint diseases.
- Asthma and severe allergic rhinitis.
- Dermatological conditions like severe eczema and psoriasis.
- Gastrointestinal inflammatory diseases such as Crohn's disease and ulcerative colitis.
- Certain blood disorders and autoimmune diseases.
The sustained-release formulation aims to provide a more consistent therapeutic effect and potentially reduce the frequency of dosing compared to immediate-release formulations, thereby improving patient compliance and managing side effects.
What is the patent expiration and status?
U.S. Patent 4,166,182 was granted on August 7, 1979.
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Patent Term: Under the patent laws in effect at the time of its grant, the patent term was generally 17 years from the date of grant or 6 years from the date of issue, whichever was longer, for applications filed before June 8, 1971. For applications filed after this date, the term was generally 17 years from the date of grant. However, for applications filed between June 8, 1971, and June 7, 1978, a transitional 20-year patent term was introduced, which became fully effective for patents granted after December 12, 1980.
Given the grant date of August 7, 1979, U.S. Patent 4,166,182 would have been subject to patent term calculations that could extend to 20 years from the filing date (approximately 17 years from grant). The application filing date is not explicitly provided in the public patent record readily accessible. However, assuming a typical prosecution period, the patent would have expired well before the present day. For instance, a 17-year term from grant would have expired in 1996. Even with potential patent term extensions, it is highly unlikely to be in force today.
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Current Status: U.S. Patent 4,166,182 is expired. Patents are granted for a fixed term, and once that term concludes, the invention enters the public domain. As this patent was granted in 1979, its statutory term has long since concluded. There are no public records indicating any post-grant maintenance challenges or successful reexamination proceedings that would alter its expired status.
What is the competitive landscape and potential for generic entry?
Given that U.S. Patent 4,166,182 has long expired, the claims related to the specific process for preparing sustained-release triamcinolone acetonide dosage forms are now in the public domain.
- Generic Entry: The expiration of this process patent removes a significant barrier to generic manufacturers. Companies seeking to produce and market generic versions of sustained-release triamcinolone acetonide oral dosage forms are free to utilize the methods described in this patent, provided they do not infringe on other, still-valid patents.
- Key Considerations for Generic Manufacturers:
- Active Pharmaceutical Ingredient (API) Patents: Generic companies must ensure they are not infringing on any existing patents covering the triamcinolone acetonide API itself, its synthesis, or specific polymorphs.
- Formulation Patents: While the process patent is expired, there might be other, later-expiring patents covering specific advanced formulations, excipient combinations, or novel drug delivery systems that also achieve sustained release. Generic manufacturers would need to develop formulations that do not infringe these.
- Bioequivalence: Generic products must demonstrate bioequivalence to the reference listed drug (RLD) approved by the U.S. Food and Drug Administration (FDA). This involves rigorous testing of dissolution profiles and pharmacokinetic parameters.
- Manufacturing Practices: Generic manufacturers must adhere to current Good Manufacturing Practices (cGMP) and obtain FDA approval for their manufacturing processes and facilities.
- Market Impact: The availability of generic versions of sustained-release triamcinolone acetonide oral dosage forms, unburdened by the claims of U.S. Patent 4,166,182, typically leads to significant price reductions and increased market accessibility. This encourages competition among pharmaceutical companies.
What are the implications for R&D and investment?
The expiration of U.S. Patent 4,166,182 has several implications for R&D and investment decisions within the pharmaceutical sector.
- Innovation Focus Shift: For originator companies, this patent's expiration signals that the specific process it protects is no longer exclusive. Future R&D investment in triamcinolone acetonide dosage forms would likely focus on developing novel formulations with enhanced properties (e.g., improved bioavailability, different release profiles, reduced side effects) that can be protected by new intellectual property, or exploring entirely new therapeutic applications for triamcinolone acetonide or related corticosteroids.
- Generic Opportunity: For generic drug manufacturers, the expired patent represents a clear opportunity. Investment can be directed towards developing and manufacturing cost-effective generic versions of sustained-release triamcinolone acetonide products. This typically involves reverse-engineering existing formulations and processes to avoid infringing on any remaining patents.
- Investment Due Diligence: Investors considering companies involved in corticosteroid manufacturing or generics need to perform thorough patent due diligence. This includes identifying all relevant expired patents (like 4,166,182) and any active patents that could pose a litigation risk or create an exclusive market for a specific product. Understanding the patent lifecycle is crucial for assessing market exclusivity and competitive advantage.
- Intellectual Property Strategy: Companies looking to enter or expand in this therapeutic area must develop robust intellectual property strategies. This might involve seeking patents for novel crystalline forms of the API, new formulations with specific excipients, improved manufacturing processes, or combination therapies. The goal is to create new, defensible patent barriers.
- Market Dynamics: The expiration of older process patents often leads to increased market competition and price erosion for established drug products. This can impact the profitability of originator companies holding less diversified portfolios and create opportunities for agile generic players. Investment in companies with strong pipelines of new, patent-protected drugs or those with efficient generic manufacturing capabilities would be favored.
Key Takeaways
- U.S. Patent 4,166,182 claims a specific process for preparing sustained-release oral dosage forms of triamcinolone acetonide through direct compression of a granular composition.
- The patent expired long ago, as it was granted in 1979.
- The expiration removes a barrier for generic manufacturers seeking to produce similar dosage forms.
- Generic entry is likely, contingent on avoiding infringement of any other active patents (e.g., API, formulation).
- For R&D, innovation must focus on new intellectual property to protect future products or processes.
- Investment decisions require thorough patent due diligence to assess market exclusivity and competitive risks.
Frequently Asked Questions
- Does U.S. Patent 4,166,182 cover the drug triamcinolone acetonide itself?
No, the patent specifically covers a process for preparing a dosage form and does not claim the active pharmaceutical ingredient (API) triamcinolone acetonide.
- Can a company still use the process described in U.S. Patent 4,166,182 today?
Yes, because the patent has expired, the described process is now in the public domain and can be used by any party, provided it does not infringe on other, still-valid patents.
- What is the significance of "direct compression" in the patent claims?
Direct compression is a pharmaceutical manufacturing technique where powder blends are directly compressed into tablets without prior granulation. This process can be more efficient and cost-effective than traditional methods. The patent claims a method for achieving this with triamcinolone acetonide for sustained release.
- Are there any patents currently active that cover sustained-release triamcinolone acetonide dosage forms?
While U.S. Patent 4,166,182 is expired, there could be other, more recently filed patents covering newer formulations, specific excipient combinations, or advanced drug delivery systems that achieve sustained release of triamcinolone acetonide. A thorough patent search is required to identify any such active patents.
- How does the expiration of this patent affect the price of triamcinolone acetonide medications?
The expiration of this process patent, along with any other relevant expired patents, generally facilitates the entry of generic competitors. Increased competition from generic manufacturers typically leads to lower prices for the medication.
Citations
[1] Schering Corporation. (1979). Process for preparing sustained-release triamcinolone acetonide oral dosage forms (U.S. Patent No. 4,166,182). Washington, DC: U.S. Patent and Trademark Office.
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