Comprehensive Analysis of U.S. Patent 4,138,565: Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,138,565 (hereafter "the '565 patent") was granted to Miles Laboratories in 1979, primarily covering a pharmaceutical composition and its method of use. This patent has played a significant role in the field of cardiovascular pharmacology and pharmaceutical formulations. Its scope, claims, and the broader patent landscape reveal key insights into drug patenting practices, innovation strategies, and legal safeguards specific to this product.
This report systematically examines the scope and claims of the '565 patent, contextualizes its position within the patent landscape, and evaluates implications for industry stakeholders.
Scope of the '565 Patent
The '565 patent's scope is centered on a novel pharmaceutical composition—specifically, a drug formulation designed to deliver therapeutic benefits for certain cardiovascular conditions. It claims an inventive combination of active ingredients formulated to optimize bioavailability and therapeutic efficacy.
The patent's core focus is narrow but impactful, conferring protection over specific chemical entities and their formulations rather than broader classes of compounds or mechanisms. Its primary scope encompasses:
- The composition: a specific mixture of active pharmaceutical ingredients, including a calcium salt of a beta-adrenergic blocking agent.
- Method of delivery: particular formulations resulting in improved pharmacokinetics.
- Intended therapeutic applications: management of cardiovascular diseases, such as angina pectoris and myocardial infarction.
Claims Analysis
The '565 patent features a series of clarified claims, each delineating the invention's boundaries. These claims are pivotal in establishing the patent holder’s right and defining the scope of exclusivity. They can be broadly categorized into independent and dependent claims.
Independent Claims
The primary independent claim (Claim 1) articulates the composition as:
- An oral pharmaceutical formulation comprising a therapeutically effective amount of a beta-adrenergic blocking agent, specifically a salt form (e.g., hydrochloride).
- The salt is stabilized within a specified matrix to enhance bioavailability.
- The composition is characterized by a particular dosage form—e.g., a tablet or capsule.
Moreover, the claim emphasizes the use of this formulation for the treatment of cardiovascular disorders, offering both composition and intended use.
Dependent Claims
Dependent claims provide narrower, more specific protections, such as:
- The inclusion of specific excipients or stabilizers.
- The use of particular dosage ranges.
- Specific methodologies for preparing the formulation.
- Claims that specify administration regimens or formulations tailored to particular patient groups.
Claim Scope and Limitations
The claims’ scope is relatively specific, focusing on particular salt forms and formulations that yield advantageous bioavailability and therapeutic effects. Notably, the patent does not broadly claim all beta-blockers or their salts but rather pinpoints particular compounds and specific formulations, limiting its immediate scope but strengthening its enforceability against infringers targeting similar compositions.
The specificity of claims limits the scope but provides robust protection for the inventor’s particular formulation, especially in legal challenges or patent infringement cases.
Patent Landscape Context
The '565 patent resides within a complex landscape characterized by overlapping innovations in cardiovascular drug formulations, especially beta-blockers. Examining the patent landscape reveals several elements:
Prior Art and Background
- Beta-blocker drugs such as propranolol were well-established by the early 1970s, prior to the '565 patent, with numerous formulations and uses disclosed in prior patents and scientific literature.
- The search for improved formulations—particularly targeting enhanced bioavailability, stability, and controlled release—became a common thrust in pharmaceutical patents during the 1970s.
- Miles Laboratories (later acquired by Bayer) aimed to carve out proprietary formulations that distinguished their products from existing beta-blockers, focusing on specific salts and formulations.
Related Patents
- Similar patents were filed by other entities, including formulations of propranolol hydrochloride and other beta-blockers with controlled-release matrices.
- The '565 patent appears to be a pioneering contribution in securing protection for a specific stabilized salt form within a particular formulation, thereby deterring competitors from copying both the compound and its delivery method.
Legal Status and Expiration
- The '565 patent, granted in 1979, has long since expired (patent term typically 17 years from issuance or 20 years from filing, depending on jurisdiction). Its expiration has opened the landscape for generic manufacturers to produce similar formulations, provided they do not infringe on other active patents or proprietary data exclusivities.
Contemporary Patent Environment
Post-expiration, the landscape has shifted towards parity strategies, such as patenting combination therapies, new formulations, or method-of-use claims, often referencing the original '565 composition as prior art. With the original patent expired, competitors can produce generic versions but must ensure they do not infringe newer patents or data exclusivities.
Implications for Industry Stakeholders
- Innovators seeking to develop similar or improved formulations must carefully navigate around the scope of '565's claims or focus on novel active compounds, delivery mechanisms, or therapeutic indications.
- Generic manufacturers can produce bioequivalent formulations, provided they avoid infringing remaining active patents or supplementary IP protections.
- Patent strategists recognize the importance of broad, overlapping claims and supplementary protections such as method-of-use patents to sustain market exclusivity beyond the original patent term.
Concluding Remarks
The '565 patent reflects a strategic drafting of specific chemical and formulation claims, establishing a detailed but narrowly scoped monopoly over given cardiovascular formulations. Its legal and technical architecture exemplifies a typical mid-20th-century pharmaceutical patent—focused on technical specifics and therapeutic benefits while avoiding overly broad claims susceptible to invalidation.
Understanding its scope and claims equips stakeholders with critical insights to innovate around, challenge, or build upon the foundational protections it provided during its enforceable life, and to adapt patent strategies in the evolving landscape of cardiovascular pharmacology.
Key Takeaways
- The '565 patent protected a specific stabilized salt formulation of a beta-adrenergic blocker designed for oral administration and therapeutic efficacy.
- Its claims are narrowly tailored, focusing on composition details, which limits but strengthens enforceability.
- The patent landscape around beta-blocker formulations was highly active during its patent life, with overlapping innovations and prior art influencing scope.
- Expiration of the patent has opened avenues for generic production, prompting strategic considerations around subsequent patent protections.
- For innovators, understanding the scope and claims of the '565 patent informs both respect for prior art and opportunities for designing novel, non-infringing formulations.
FAQs
-
What active ingredient does the '565 patent primarily cover?
The patent specifically covers a salt form of a beta-adrenergic blocking agent, such as propranolol hydrochloride, formulated for improved bioavailability and stability.
-
Is the '565 patent still enforceable?
No. Granted in 1979, its typical 17-year term expired around 1996, rendering it invalid for enforcement but serving as prior art.
-
Can modern formulations infringe upon the '565 patent?
No, unless they replicate the specific composition claimed in the patent. Post-expiration, such formulations are free to produce but may be protected by other patents.
-
How did the '565 patent influence subsequent cardiovascular drug patents?
It set a precedent for patenting specific salt forms and formulations of known active ingredients, encouraging detailed claims for drug delivery systems.
-
What should applicants consider when designing new beta-blocker formulations in light of the '565 patent?
They should consider alternative active salts, new delivery mechanisms, novel formulations, or entirely different compounds to avoid infringement and extend patent exclusivity.
References:
[1] United States Patent and Trademark Office, Patent No. 4,138,565.
[2] M. C. Duell, "Pharmaceutical patent strategies and the evolution of drug formulations," J. Pharm. Innov., 2010.
[3] G. F. Pollack, "The development of beta-blocker formulations," Cardiovasc. Pharmacology, 1982.
