United States Patent 6,893,662: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 6,893,662, titled "Pharmaceutical dosage form with multiple coatings for reduced impact of coating fractures," is a significant patent in the pharmaceutical industry, particularly in the formulation and delivery of oral medications. This patent, issued to Allergan Pharmaceuticals International Limited, addresses a critical issue in drug delivery systems and has substantial implications for both the manufacturer and the consumer.
Technical Field and Background
The patent pertains to the field of pharmaceutical compositions, specifically solid unit dosage forms designed for oral administration. It builds upon earlier innovations in drug delivery systems, focusing on the improvement of coating technologies to enhance the efficacy and stability of pharmaceuticals[4].
Summary of the Invention
The patent describes a pharmaceutical composition that includes a solid unit dosage form, typically a tablet, coated with multiple layers. These layers are designed to reduce the impact of coating fractures, which can occur during the manufacturing process or during the passage of the tablet through the gastrointestinal tract. The coating layers are composed of materials such as poly(meth)acrylates, which provide a protective barrier and ensure the controlled release of the active pharmaceutical ingredient (API)[4].
Key Claims
The patent includes several key claims that define the scope of the invention:
Claim 1
The patent claims a pharmaceutical composition in a solid unit dosage form for oral administration, comprising an active pharmaceutical ingredient and multiple coating layers. These layers include an inner coating layer and an outer coating layer, both of which are composed of poly(meth)acrylates[4].
Claim 2
This claim specifies the materials used in the coating layers, including methyl methacrylate and methacrylic acid, which are key components of the poly(meth)acrylate coatings[4].
Claim 3
This claim details the process of applying the multiple coating layers to the solid unit dosage form, ensuring that the coatings are intact and effective in reducing the impact of fractures[4].
Patent Landscape
Related Patents
The patent landscape surrounding U.S. Patent 6,893,662 includes other patents related to pharmaceutical dosage forms and coating technologies. For example, the World Intellectual Property Organization (WIPO) patent WO2014091308A1 describes a formulation for 5-aminosalicylic acid capsules, which also involves enteric and polyacrylate coatings, highlighting the broader context of coating technologies in pharmaceuticals[2].
Expiration and Litigation
The patent expired on November 15, 2021, marking the end of its protective period. Prior to its expiration, the patent was subject to litigation, including a case initiated by Warner Chilcott Company, LLC against Zydus Pharmaceuticals (USA) Inc. for infringement of the ‘662 patent. This case was eventually dismissed[1].
Generic Drug Exclusivity
The expiration of this patent also opened the door for generic versions of the drug. Zydus Pharmaceuticals (USA) Inc. was the first ANDA applicant to submit a substantially complete application with a paragraph IV certification, making them eligible for 180 days of generic drug exclusivity for Mesalamine Delayed-Release Tablets USP, 800 mg[1].
Bioequivalence and Therapeutic Equivalence
The FDA has determined that generic versions of the drug, such as Mesalamine Delayed-Release Tablets USP, 800 mg by Zydus Pharmaceuticals, are bioequivalent and therapeutically equivalent to the reference listed drug (RLD), Asacol HD Delayed-Release Tablets, 800 mg by Allergan Pharmaceuticals International Limited. This ensures that the generic versions provide the same therapeutic effect as the branded drug[1].
Impact on Pharmaceutical Industry
Manufacturing and Quality Control
The patent's focus on multiple coating layers has significant implications for manufacturing processes. It emphasizes the importance of robust quality control measures to ensure the integrity of the coatings, which is crucial for the stability and efficacy of the drug. Manufacturers must incorporate dissolution testing into their stability and quality control programs to comply with regulatory standards[1].
Patient Benefits
For patients, the invention ensures that the drug is delivered in a controlled manner, reducing the risk of coating fractures and ensuring consistent therapeutic effects. This enhances patient compliance and outcomes, particularly for chronic conditions where consistent drug delivery is critical.
Conclusion
U.S. Patent 6,893,662 represents a significant advancement in pharmaceutical coating technologies, addressing a critical issue in drug delivery systems. The patent's claims and the broader patent landscape highlight the importance of innovative coating materials and processes in ensuring the efficacy and stability of oral medications.
Key Takeaways
- Multiple Coating Layers: The patent introduces a pharmaceutical composition with multiple coating layers to reduce the impact of coating fractures.
- Poly(meth)acrylates: The use of poly(meth)acrylates in the coating layers is a key innovation.
- Expiration and Litigation: The patent expired on November 15, 2021, and was subject to litigation prior to its expiration.
- Generic Drug Exclusivity: Zydus Pharmaceuticals was eligible for 180 days of generic drug exclusivity following the patent's expiration.
- Bioequivalence and Therapeutic Equivalence: Generic versions of the drug are bioequivalent and therapeutically equivalent to the branded version.
FAQs
What is the main innovation of U.S. Patent 6,893,662?
The main innovation is the use of multiple coating layers composed of poly(meth)acrylates to reduce the impact of coating fractures in pharmaceutical dosage forms.
What is the significance of the coating layers in this patent?
The coating layers ensure the controlled release of the active pharmaceutical ingredient and protect against coating fractures, enhancing the stability and efficacy of the drug.
When did the patent expire?
The patent expired on November 15, 2021.
What was the outcome of the litigation involving this patent?
The litigation initiated by Warner Chilcott Company, LLC against Zydus Pharmaceuticals (USA) Inc. was eventually dismissed.
Who was eligible for generic drug exclusivity following the patent's expiration?
Zydus Pharmaceuticals (USA) Inc. was eligible for 180 days of generic drug exclusivity for Mesalamine Delayed-Release Tablets USP, 800 mg.
Sources
- FDA ANDA 203286: Abbreviated New Drug Application for Mesalamine Delayed-Release Tablets USP, 800 mg.
- WIPO Patent WO2014091308A1: 5-aminosalicylic acid capsule formulation.
- USPTO Patent Claims Research Dataset: Detailed information on claims from US patents.
- US Patent 6,893,662B2: Pharmaceutical dosage form with multiple coatings for reduced impact of coating fractures.
