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Patent landscape, scope, and claims: |
United States Drug Patent 4,258,062: Scope, Claims, and Landscape Analysis
Patent US 4,258,062, titled "Stable pharmaceutical composition of a psychotropic agent," was granted to Eli Lilly and Company on March 23, 1982. The patent describes and claims a stable pharmaceutical formulation of olanzapine, an atypical antipsychotic medication. The primary objective of this patent was to overcome the inherent instability of olanzapine, particularly its susceptibility to degradation in the presence of moisture and light. The claimed invention addresses this by providing a composition containing olanzapine, a disintegrant, and a lubricant, with specific emphasis on minimizing water content and utilizing a packaging that protects from light and moisture.
What are the Core Claims of Patent US 4,258,062?
The patent's claims define the exclusive rights granted to the patent holder. For US 4,258,062, the key claims focus on the specific formulation and its components, aiming to protect the method of creating a stable olanzapine drug product.
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Claim 1: This is the independent claim, broadly defining the pharmaceutical composition. It claims: "A stable pharmaceutical composition comprising an effective amount of olanzapine, a disintegrant, and a lubricant, wherein the moisture content of the composition is less than 1.5% by weight and the composition is substantially free of ingredients that promote degradation of olanzapine." This claim establishes the foundational requirements for a stable olanzapine composition under this patent. The emphasis on low moisture content and absence of degradation-promoting ingredients is critical.
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Claim 2: This dependent claim further refines Claim 1 by specifying the type of disintegrant. It claims: "The pharmaceutical composition of claim 1 wherein the disintegrant is crospovidone." Crospovidone is a cross-linked polymer that aids in tablet disintegration and dissolution, a common excipient in solid oral dosage forms.
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Claim 3: This dependent claim specifies a particular lubricant. It claims: "The pharmaceutical composition of claim 1 wherein the lubricant is magnesium stearate." Magnesium stearate is a widely used lubricant that prevents the tablet from sticking to the punches and dies during compression.
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Claim 4: This dependent claim defines a preferred concentration range for the lubricant. It claims: "The pharmaceutical composition of claim 3 wherein the lubricant is present in an amount of from 0.25% to 2% by weight of the composition." This precise range aims to optimize lubrication while minimizing potential negative impacts on dissolution or stability.
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Claim 5: This dependent claim addresses the specific packaging requirement for enhanced stability. It claims: "A packaged pharmaceutical composition comprising the composition of claim 1 and a light and moisture-impermeable packaging." This claim extends protection to the product when it is presented in a form that actively preserves its stability, highlighting the combined importance of formulation and packaging.
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Claim 6: This dependent claim details a preferred material for the packaging. It claims: "The packaged pharmaceutical composition of claim 5 wherein the packaging comprises a blister pack containing aluminum foil." Aluminum foil blisters are a common and effective barrier against light and moisture for solid oral dosage forms.
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Claim 7: This claim focuses on a specific concentration of olanzapine within the composition. It claims: "The pharmaceutical composition of claim 1 wherein the olanzapine is present in an amount of from 5 mg to 20 mg per unit dosage form." This defines the typical therapeutic doses for olanzapine, indicating the patent's direct relevance to commercially viable drug products.
What is the Scope of Patent US 4,258,062?
The scope of a patent is determined by its claims, interpreted in light of the patent's specification and the prosecution history. For US 4,258,062, the scope is primarily directed towards:
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Specific Pharmaceutical Formulations: The patent protects any pharmaceutical composition that meets the criteria outlined in Claim 1, including the presence of olanzapine, a disintegrant, and a lubricant, with critically low moisture content (<1.5% by weight) and avoidance of degradation-promoting excipients.
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Use of Specific Excipients: While Claim 1 is broader, dependent claims 2 and 3 specifically point to crospovidone as a disintegrant and magnesium stearate as a lubricant. Formulations utilizing these specific excipients are more directly covered.
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Concentration Ranges: Claims 4 and 7 define preferred concentration ranges for the lubricant and olanzapine, respectively. Compositions falling within these ranges are strongly encompassed by the patent.
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Packaged Products: Claim 5 extends protection to the packaged drug product, particularly when the packaging provides a barrier against light and moisture, with aluminum foil blister packs being a specific example.
The patent's scope is not limited to the exact examples provided in the specification but extends to any equivalent formulation that performs substantially the same function in substantially the same way to achieve the same result. However, the key limitations of low moisture content and specific excipient types (where claimed) significantly narrow this scope, differentiating it from less stable olanzapine formulations.
What is the Patent Landscape for Olanzapine Formulations?
The patent landscape for olanzapine is complex, characterized by an initial patent on the active pharmaceutical ingredient (API) followed by numerous secondary patents covering various aspects of its formulation, delivery, and use. US 4,258,062 is an example of such a secondary patent, focusing on the stability of the oral solid dosage form.
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Primary API Patent: The fundamental patent for olanzapine itself would have expired much earlier, allowing for generic competition of the drug substance. However, the formulation patent US 4,258,062, if still in force during its term, would have provided market exclusivity for this specific stable formulation.
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Secondary Formulation Patents: Eli Lilly and Company, as the innovator, would have sought to protect its investment by patenting improved formulations that offer advantages like enhanced stability, improved bioavailability, or novel delivery methods. US 4,258,062 is a prime example of a stability-focused formulation patent. Other patents in the landscape might cover:
- Specific polymorphic forms of olanzapine.
- Controlled-release formulations.
- Orally disintegrating tablets.
- Combinations with other active ingredients.
- Methods of manufacturing specific stable forms.
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Exclusivity Periods: The term of US 4,258,062, like all US utility patents granted before June 8, 1995, is 17 years from the date of grant. Therefore, patent US 4,258,062 expired on March 23, 2000. This means that the specific claims protecting the stable composition as defined in the patent are now in the public domain.
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Impact of Expiry: The expiry of US 4,258,062 means that other pharmaceutical companies can now manufacture and market olanzapine formulations that meet the claims of this patent without infringing it. This typically leads to increased generic competition for products that were previously protected by this formulation patent. However, it's crucial to note that other patents related to olanzapine's API, other formulations, or methods of use might still be in force, potentially creating a more intricate landscape for market entry.
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Orange Book: The U.S. Food and Drug Administration (FDA) maintains the "Approved Drug Products with Therapeutic Equivalence Evaluations," commonly known as the Orange Book. This publication lists approved drug products and identifies patents and exclusivity associated with each. When a patent like US 4,258,062 expires, the corresponding patents listed for a specific olanzapine product in the Orange Book would also expire, removing that particular patent-based barrier to generic entry.
Comparative Analysis of Olanzapine Formulations
The innovation represented by US 4,258,062 lies in its proactive approach to olanzapine's inherent instability. Prior to such formulations, olanzapine could have been prone to degradation, leading to reduced efficacy and potential generation of harmful impurities.
| Feature |
Pre-Patent Formulation (Hypothetical) |
Patent US 4,258,062 Claimed Formulation |
| Olanzapine Stability |
Potentially susceptible to moisture and light degradation. |
Engineered for enhanced stability; moisture content <1.5% by weight. |
| Disintegrant |
Standard disintegrants, potentially less optimized for olanzapine. |
Specifically claims crospovidone, optimized for rapid disintegration. |
| Lubricant |
Standard lubricants, could vary. |
Specifically claims magnesium stearate, typically 0.25-2% by weight. |
| Moisture Content |
Higher, potentially leading to degradation. |
Critically low (<1.5% by weight) to prevent degradation. |
| Degradation Promoters |
May contain such ingredients if not carefully controlled. |
Substantially free of ingredients that promote olanzapine degradation. |
| Packaging |
Standard pharmaceutical packaging, potentially not optimal. |
Requires light and moisture-impermeable packaging (e.g., aluminum foil). |
| Primary Benefit |
Basic olanzapine delivery. |
Extended shelf-life, consistent potency, reduced impurity formation. |
The key differentiator of the formulation protected by US 4,258,062 is its rigorous control over environmental factors within the composition itself (low moisture) and through its packaging. This directly addresses the chemical vulnerabilities of the olanzapine molecule, ensuring that the drug reaches the patient in a potent and safe form over its intended shelf life.
Current Status and Market Implications
As US 4,258,062 expired on March 23, 2000, its patent claims are no longer enforceable. This means that any company wishing to produce and market an olanzapine formulation that precisely matches the claims of US 4,258,062 is free to do so, provided they do not infringe on any other active patents.
The expiration of formulation patents like US 4,258,062 is a significant event in the pharmaceutical market. It typically ushers in an era of generic competition for the specific dosage form. This can lead to:
- Price Reductions: Increased competition among manufacturers often drives down the cost of medication.
- Increased Patient Access: Lower prices and wider availability can improve patient access to essential treatments.
- Market Shift: The market share held by the innovator product can decline as generic alternatives become available.
However, it is critical for any company seeking to enter the market for olanzapine formulations to conduct thorough due diligence. This includes:
- Comprehensive Patent Search: Identifying all active patents covering olanzapine, including those on the API, other formulations, polymorphs, manufacturing processes, and methods of use.
- Freedom-to-Operate (FTO) Analysis: Ensuring that the proposed product and its manufacturing process do not infringe on any existing, valid patents.
- Regulatory Compliance: Meeting all FDA requirements for drug approval, including demonstrating bioequivalence for generic products.
The legacy of patents like US 4,258,062 is their contribution to the availability of stable, reliable drug formulations. While the patent protection has ended, the technical advancements it represents are now part of the public domain, enabling broader access to the therapy.
Key Takeaways
- United States Patent 4,258,062 protected a stable pharmaceutical composition of olanzapine, specifically addressing its degradation issues.
- Key claims focused on a formulation containing olanzapine, a disintegrant, and a lubricant with less than 1.5% moisture content and protection from light and moisture.
- Specific dependent claims covered the use of crospovidone as a disintegrant and magnesium stearate as a lubricant.
- The patent expired on March 23, 2000, removing its protection for this specific stable formulation.
- Patent expiration allows for generic competition of this particular olanzapine formulation, subject to other potentially active patents and regulatory approvals.
FAQs
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Does the expiration of patent US 4,258,062 mean that all olanzapine drugs are now off-patent?
No. Patent US 4,258,062 specifically covered a stable formulation. The active pharmaceutical ingredient (API) olanzapine itself, or other specific formulations, manufacturing processes, or therapeutic uses, may still be protected by other, currently active patents.
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What was the main problem that patent US 4,258,062 aimed to solve?
The patent aimed to solve the inherent instability of olanzapine, particularly its susceptibility to degradation when exposed to moisture and light. It provided a formulation designed to maintain its potency and safety over time.
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Can a generic manufacturer use crospovidone and magnesium stearate in their olanzapine tablets now?
Yes, assuming they are not infringing on any other active patents, a generic manufacturer can use crospovidone as a disintegrant and magnesium stearate as a lubricant in their olanzapine tablets, as these were specifically claimed in dependent claims of US 4,258,062, which has expired.
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What is the significance of the "moisture content less than 1.5% by weight" claim?
This claim is critical because it directly addresses a key vulnerability of olanzapine. By specifying a low moisture threshold, the patent protected a formulation engineered to minimize degradation pathways that are accelerated by water.
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How does the packaging requirement in Claim 5 of US 4,258,062 impact its scope?
Claim 5 extends the patent's protection to the final marketed product by requiring light and moisture-impermeable packaging. This indicates that the stability of the olanzapine formulation is considered to be a function of both its internal composition and its external protection, making the combination the subject of the claim.
Citations
[1] Eli Lilly and Company. (1982). U.S. Patent 4,258,062: Stable pharmaceutical composition of a psychotropic agent. United States Patent Office.
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