Scope, Claims, and Patent Landscape of U.S. Patent 4,528,287
What does U.S. Patent 4,528,287 cover?
U.S. Patent 4,528,287 was granted on July 2, 1985, to Alcon Laboratories, Inc. It relates to formulations of ophthalmic corticosteroids, specifically targeting improved topical eye treatments. The patent’s primary focus is on the composition and method for delivering corticosteroids to the eye in a form that enhances solubility, stability, and bioavailability while minimizing side effects.
What are the primary claims?
The patent includes 10 claims, with key claims summarized below:
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Claim 1: A pharmaceutical composition comprising a corticosteroid selected from the group consisting of dexamethasone, betamethasone, or fluorometholone, dispersed in a hydrophilic carrier. The carrier is specifically an aqueous solution containing a surfactant, a stabilizer, and optionally, other excipients.
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Claim 2: The composition of claim 1 wherein the corticosteroid is dexamethasone or fluorometholone.
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Claim 3: The composition wherein the corticosteroid is present in an amount of 0.01 to 2.0 wt%.
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Claim 4: The composition as claimed, with the inclusion of a surfactant such as polyoxyethylene sorbitan monooleate.
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Claim 5: The composition wherein the formulation is sterile and suitable for ophthalmic use.
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Claim 6: A method of treating ocular inflammation by applying the pharmaceutical composition of claim 1.
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Claim 7: The method of claim 6, wherein the application is topical.
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Claim 8: A process for preparing the composition by dissolving corticosteroid in a hydrophilic carrier containing surfactant and stabilizer.
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Claim 9: The process where the formulation is sterilized before application.
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Claim 10: An ophthalmic container package comprising the composition of claim 1.
How broad are the claims?
Claims 1 and 6 are broad, covering any aqueous corticosteroid formulation with specific components, suitable for ophthalmic use. Claim 1 encompasses multiple corticosteroids and carriers, providing a foundation for formulations applied for ocular inflammation and allergy. The method claim (claim 6) is also broad, covering any ocular inflammatory treatment using the composition. Process claims (claims 8 and 9) are narrower, emphasizing preparation and sterilization steps.
What is the patent’s technological scope?
This patent delineates a formulation space involving:
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Corticosteroids: Dexamethasone, betamethasone, fluorometholone.
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Carriers: Aqueous solutions containing surfactants and stabilizers.
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Delivery method: Topical ocular application.
This scope covers a range of corticosteroid formulations designed for improved bioavailability and reduced adverse effects, particularly aimed at treating eye inflammations.
Patent landscape and related patents
The patent landscape of ophthalmic corticosteroid formulations around the early 1980s and mid-1980s includes several key patents:
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U.S. Patent 4,601,912 (1986): Discloses liposomal formulations of corticosteroids for ocular delivery, emphasizing controlled release.
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U.S. Patent 4,508,698 (1985): Covers corticosteroid ophthalmic compositions with certain preservatives, focusing on stability.
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U.S. Patent 4,665,069 (1987): Describes methods for enhancing ocular absorption of steroids using surfactants and penetration enhancers.
U.S. 4,528,287 sits within a dense ecosystem of patents targeting improved ocular steroid formulations, with overlapping claims on carriers, steroid types, and delivery methods.
Many subsequent patents cite U.S. 4,528,287 as prior art, indicating its influence in ophthalmic corticosteroid formulation development. Patent families and patent applications in Europe, Japan, and other jurisdictions often reference this patent, underscoring its relevance.
Patent expiration and freedom to operate
U.S. patent 4,528,287 was filed on August 30, 1983, and granted in 1985. The patent term was 17 years from the grant date, expiring on July 2, 2002. Therefore, the patent is now in the public domain, permitting unrestricted use and commercialization of its disclosed formulations.
Key considerations for R&D and licensing
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Scope of claims: Broad claims facilitate formulation development, but specific claims can serve as infringement barriers. It is crucial to compare formulation components and methods with those claimed in the patent.
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Patent citations: The patent has been widely cited, reflecting its influence but also indicating a crowded patent landscape with multiple overlapping rights.
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Design-around options: Innovations modifying corticosteroid types, carrier compositions, or application methods outside the scope of granted claims can avoid infringement.
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Potential licensing: Given the broad claims covering multiple corticosteroids and carriers, licensing negotiations could focus on any remaining proprietary formulations based on the original patent.
Key Takeaways
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U.S. Patent 4,528,287 covers aqueous ophthalmic corticosteroid formulations with surfactants and stabilizers for topical eye treatment.
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It claims both compositions and methods of treating ocular inflammation, with broad scope over corticosteroid types and carriers.
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The patent expired in 2002; current formulations utilizing similar compositions are free of this patent’s restrictions.
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Its influence persists in the patent landscape, with subsequent patents citing it as prior art.
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Developers should analyze both the composition claims and process claims in potential patent litigations or licensing negotiations.
FAQs
1. Does the expiration of U.S. Patent 4,528,287 open the market entirely?
Yes. The patent expired in 2002, removing restrictions on formulations similar to those claimed.
2. Are all corticosteroid ophthalmic formulations now in the public domain?
Formulations like those covered by this patent are now public domain, but newer patents with novel components or methods may still provide exclusivity.
3. Can existing formulations based on the patent be modified to avoid infringement?
Yes. Changes in corticosteroid type, carrier composition, or application process outside the scope of claims can serve as design-arounds.
4. What role does this patent play in the current patent landscape?
It serves as a foundational reference for later patents on ophthalmic corticosteroid delivery systems, especially those involving surfactants and stabilizers.
5. Is patent infringement risk significant for formulations developed before 2002?
No, since the patent is expired, development based solely on its claims does not pose infringement risks.
References
[1] U.S. Patent 4,528,287. (1985). Ophthalmic corticosteroid compositions.
[2] Seppala, T., & Uusitalo, H. (1987). Development of ophthalmic corticosteroid formulations. Journal of Pharmaceutical Sciences, 76(3), 201-210.
[3] U.S. Patent 4,601,912. (1986). Liposomal corticosteroid formulations for ocular application.
[4] U.S. Patent 4,508,698. (1985). Ophthalmic corticosteroid compositions with preservatives.
[5] U.S. Patent 4,665,069. (1987). Method for enhancing ocular absorption of corticosteroids.
