US Patent 4,587,252: Scope, Claims, Expiration, Litigation, and Patent Landscape for Hydrocodone-Ibuprofen

US Patent 4,587,252 covers analgesic treatment and pharmaceutical compositions combining hydrocodone, or a pharmaceutically acceptable salt, with ibuprofen. The core disclosed ratio is one part hydrocodone to approximately 20 to 80 parts ibuprofen, with representative unit doses of 5 to 10 mg hydrocodone and 200 to 400 mg ibuprofen. The patent issued on May 6, 1986, and its enforceable term expired in 2003. It does not create a current barrier to generic hydrocodone-ibuprofen products.

What does US Patent 4,587,252 protect?

US Patent 4,587,252 protects two related subject matter categories:

A method of treating pain with a hydrocodone-ibuprofen combination.
A pharmaceutical composition containing the combination, including a pharmaceutical carrier and specified dosage ranges.

The claims are directed to the combination’s analgesic use and composition, not to a particular brand, tablet shape, manufacturing process, release mechanism, or excipient system.

Patent	Title	Filing date	Issue date	Principal subject	Current status
US 4,587,252	Analgesic compositions containing hydrocodone and ibuprofen	1984	May 6, 1986	Hydrocodone-ibuprofen analgesic combinations	Expired

The patent is associated with the hydrocodone-ibuprofen product later commercialized as Vicoprofen. FDA approved Vicoprofen, containing hydrocodone bitartrate and ibuprofen, in 1997 under NDA 20-716.[1]

How many claims does US 4,587,252 contain?

The patent has six claims. Claims 1, 3, and 5 are method-of-treatment claims. Claims 2, 4, and 6 are composition claims.

Claim	Category	Main limitation
1	Method	Administering hydrocodone plus ibuprofen in a ratio producing greater analgesia than either agent alone
2	Composition	Hydrocodone plus ibuprofen in a ratio producing greater analgesia than either agent alone
3	Method	Administering one part hydrocodone and about 20 to 80 parts ibuprofen by weight
4	Composition	Carrier plus one part hydrocodone and about 20 to 80 parts ibuprofen by weight
5	Method	Administering approximately 5 to 10 mg hydrocodone and 200 to 400 mg ibuprofen
6	Composition	Unit dosage form containing approximately 5 to 10 mg hydrocodone and 200 to 400 mg ibuprofen

The claims use “hydrocodone” and “ibuprofen” broadly enough to include pharmaceutically acceptable acid-addition or other pharmaceutically acceptable salts. Commercial products generally use hydrocodone bitartrate with ibuprofen.

What is the scope of claim 1?

Claim 1 is a functional method claim. It requires:

Treatment of pain in a mammal.
Administration of a pharmaceutical composition.
Hydrocodone or a pharmaceutically acceptable acid-addition salt.
Ibuprofen or a pharmaceutically acceptable acid-addition salt.
A ratio that produces a greater analgesic effect than hydrocodone or ibuprofen alone.

The claim is broader than claims 3 and 5 because it does not specify a numerical ratio or fixed dosage. Its key limitation is the comparative analgesic result.

That result creates a potential proof issue. A claimant would need to establish that the accused combination falls within the claimed range and provides the required greater analgesic effect. The relevant comparison would generally involve hydrocodone alone and ibuprofen alone under appropriate experimental conditions.

Claim 1 does not expressly require:

A tablet.
A capsule.
A particular release profile.
A particular patient population.
A particular pain condition.
A specific administration frequency.
A defined hydrocodone-to-ibuprofen dosage such as 7.5 mg/200 mg.

What is the scope of claim 2?

Claim 2 is the composition counterpart to claim 1. It covers a pharmaceutical composition containing hydrocodone and ibuprofen in amounts sufficient to produce an analgesic effect, subject to the comparative-effect limitation.

Compared with claim 1, claim 2 does not require an act of administration. A product could potentially satisfy the claim based on its composition and the claimed functional relationship.

The claim is composition-focused but still depends on a functional limitation. A composition containing the two active ingredients is not necessarily within claim 2 unless the claimed ratio produces greater analgesia than either active ingredient alone.

What do claims 3 and 4 protect?

Claims 3 and 4 define the central numerical ratio: one part hydrocodone to approximately 20 to 80 parts ibuprofen by weight.

Claim 3: method of treatment

Claim 3 covers administering the combination to treat pain. The ratio is expressed as:

One part hydrocodone, or an acceptable salt.
Approximately 20 to 80 parts ibuprofen, or an acceptable salt.

A 1:20 ratio is at the low end of the claim. A 1:80 ratio is at the high end. Ratios outside that range require separate analysis under the broader claims and cannot be assumed to infringe claim 3.

Claim 4: pharmaceutical composition

Claim 4 covers a composition containing:

A pharmaceutically acceptable carrier.
An analgesically effective amount of hydrocodone or a hydrocodone salt.
Approximately 20 to 80 parts ibuprofen for each part hydrocodone.

The carrier limitation is typical of a dosage-form claim. The claim does not limit the carrier to a particular binder, diluent, lubricant, coating, capsule shell, or excipient.

What dosage range is protected by claims 5 and 6?

Claims 5 and 6 specify a narrower unit-dose range:

Hydrocodone: approximately 5 to 10 mg.
Ibuprofen: approximately 200 to 400 mg.

Claim 5 is a treatment claim. Claim 6 is a unit-dose composition claim.

The ranges include common commercial strengths such as:

Hydrocodone	Ibuprofen	Nominal ratio
5 mg	200 mg	1:40
7.5 mg	200 mg	1:26.7
10 mg	400 mg	1:40
5 mg	400 mg	1:80
10 mg	200 mg	1:20

The commercial Vicoprofen strength of 7.5 mg hydrocodone bitartrate and 200 mg ibuprofen falls within the numerical ranges described in claims 3 through 6, subject to the legal treatment of salt weight, active-moiety equivalence, and other claim-construction issues.[1]

Does the patent cover Vicoprofen?

The patent covers the core active-ingredient combination and dosage concept used by Vicoprofen. Vicoprofen contains hydrocodone bitartrate and ibuprofen in a fixed oral dosage form. FDA labeling identifies the product as a combination analgesic indicated for short-term management of acute pain severe enough to require an opioid analgesic when alternative treatments are inadequate.[1]

The patent does not necessarily cover every feature of the marketed product. Separate protection would be required for:

A specific tablet coating.
A particular manufacturing process.
A controlled-release formulation.
A novel excipient system.
A specific packaging configuration.
A later-developed abuse-deterrent design.

No such limitation appears in the six claims provided.

When did US Patent 4,587,252 lose exclusivity?

The patent expired in 2003. Because it issued in 1986, its original US patent term was generally governed by the pre-1995 17-year term measured from grant. The ordinary expiration date was therefore May 6, 2003, absent an unusual adjustment, terminal disclaimer, or other patent-specific event.[2]

Event	Date
Patent issued	May 6, 1986
FDA approval of Vicoprofen	July 23, 1997
Ordinary patent expiration	May 6, 2003
Current enforceability	None

FDA approval occurred after issuance but did not preserve the patent beyond its statutory term. Any patent-term extension would have had to be obtained under the Hatch-Waxman patent-term-extension framework before expiration. There is no current enforceable term associated with US 4,587,252.

What was the Orange Book status of US 4,587,252?

The patent was relevant to the Vicoprofen regulatory history, but it is not a current Orange Book exclusivity barrier. FDA’s Orange Book identifies patents and regulatory exclusivities associated with approved drug products. Once a listed patent expires, it no longer blocks approval or launch on the basis of patent term.[3]

The patent’s practical Orange Book significance was historical:

It identified core combination technology associated with Vicoprofen.
It could have affected the timing of abbreviated new drug application approval while unexpired.
Its expiration removed the principal patent obstacle to generic hydrocodone-ibuprofen products.

The Orange Book does not convert an expired composition patent into a continuing market right.

Were there Paragraph IV challenges to US 4,587,252?

A Paragraph IV certification is relevant when an ANDA applicant asserts that a listed patent is invalid, unenforceable, or will not be infringed. Because US 4,587,252 expired in 2003, later generic applicants could rely on patent expiration rather than maintain a live Paragraph IV dispute against this patent.

Publicly available regulatory and patent records do not establish a current Paragraph IV controversy involving US 4,587,252. Any historical certification would have lost practical significance after expiration.

Generic applicants could still face other patents, regulatory exclusivity, controlled-substance requirements, or commercial barriers. Those issues are separate from the expired patent.

What patent litigation affects hydrocodone-ibuprofen products?

US 4,587,252 is not a current litigation threat. Its expiration means that an owner cannot obtain an injunction or damages for post-expiration conduct based solely on the patent.

Potential litigation involving hydrocodone-ibuprofen products would more likely concern:

A later formulation patent.
A manufacturing patent.
A patent covering abuse-deterrent technology.
Trademark or trade-dress rights.
Controlled-substance distribution and compliance.
Product liability or labeling issues.
ANDA procedure unrelated to this expired patent.

The six claims do not provide a current basis for a patent infringement action against a generic manufacturer.

How strong is the patent estate for hydrocodone and ibuprofen?

The historical estate was commercially important but technically narrow in its center of gravity. Its strongest features were the direct coverage of the active-ingredient combination and the specified dose and ratio ranges. Its present strength is zero as an exclusionary right because the patent expired.

Dimension	Assessment
Core combination coverage	Strong historically
Numerical ratio coverage	Defined by 1:20 to 1:80
Unit-dose coverage	Defined by 5 to 10 mg hydrocodone and 200 to 400 mg ibuprofen
Formulation specificity	Limited
Manufacturing protection	Not present in the supplied claims
Method-of-use breadth	Broad for pain treatment, subject to functional limitations
Current enforceability	None
Generic entry barrier	None from this patent

The functional “greater analgesic effect” language may have created claim-construction and proof questions during the patent’s life. Claims 3 through 6 are more objective because they use numerical dosage and ratio limitations, although salt identity and weight calculations can affect infringement analysis.

What generic launch risks exist?

The patent-related generic launch risk from US 4,587,252 is zero because the patent expired in 2003. FDA-approved generic hydrocodone-ibuprofen products can compete without obtaining a license from the former patent owner.

Remaining launch risks arise from other sources:

FDA approval and labeling requirements.
Schedule II controlled-substance compliance.
Opioid distribution controls.
Manufacturing capacity.
DEA registration and quota requirements.
Pharmacist and wholesaler purchasing policies.
State opioid regulations.
Product liability exposure.
Supply constraints for hydrocodone and ibuprofen.

An ANDA applicant also must ensure that its product label does not introduce unapproved indications or dosing instructions. The reference product’s labeling is relevant to the ANDA pathway.[1]

Are biosimilar risks relevant?

No. Hydrocodone and ibuprofen are small-molecule active pharmaceutical ingredients. Products containing them are regulated as small-molecule drugs, generally through the NDA and ANDA pathways under the Federal Food, Drug, and Cosmetic Act.

The Biologics Price Competition and Innovation Act and the FDA Purple Book are not applicable to this patent or to hydrocodone-ibuprofen tablets. The competitive threat is generic substitution, not biosimilar entry.

How does this patent compare with later formulation patents?

US 4,587,252 is a foundational active-ingredient combination patent. A later formulation patent could be materially different if it claims:

Modified release.
Abuse deterrence.
Reduced gastrointestinal injury.
A specific particle-size distribution.
A defined dissolution profile.
A novel coating or multilayer tablet.
A manufacturing process that improves stability.

Such a later patent could remain relevant after US 4,587,252 expired. The supplied claims do not provide that type of secondary protection.

What licensing deals or commercial rights are associated with the patent?

The patent was commercially connected to the hydrocodone-ibuprofen product later marketed as Vicoprofen. FDA records identify the reference product and its sponsor history, but the supplied claim set does not establish the terms of any patent assignment, license, royalty agreement, or collaboration.

Because the patent expired, any historical license no longer creates a current patent-based generic entry restriction. Commercial arrangements involving trademarks, manufacturing, supply, or distribution may survive independently, but they are not established by the claims.

What is the current competitive landscape?

The relevant market consists of:

Generic hydrocodone bitartrate and ibuprofen tablets.
The Vicoprofen reference product, where commercially available.
Hydrocodone-acetaminophen products.
Ibuprofen-only products.
Other opioid and non-opioid acute-pain therapies.

Hydrocodone-ibuprofen has a differentiated pharmacologic profile because it combines an opioid analgesic with a nonsteroidal anti-inflammatory drug and avoids acetaminophen exposure. Its use remains constrained by opioid scheduling, NSAID-related gastrointestinal and renal risks, and short-duration labeling.

Key Takeaways

US Patent 4,587,252 covers hydrocodone-ibuprofen pain-treatment methods and compositions.
Claims 3 through 6 define the principal numerical scope: one part hydrocodone to about 20 to 80 parts ibuprofen, with 5 to 10 mg hydrocodone and 200 to 400 mg ibuprofen unit doses.
The 7.5 mg/200 mg Vicoprofen strength falls within the disclosed dosage and ratio ranges.
The patent issued May 6, 1986, and expired in 2003.
It is not a current Orange Book or Paragraph IV barrier.
No biosimilar pathway is relevant.
Generic entry risk from this patent is zero.
Any current exclusivity would have to arise from a later patent, regulatory right, trademark, manufacturing arrangement, or controlled-substance compliance issue.

FAQs

Does US Patent 4,587,252 cover hydrocodone-acetaminophen products?

No. The claims require ibuprofen. Hydrocodone-acetaminophen products fall outside the express active-ingredient limitations.

Does the patent cover separate hydrocodone and ibuprofen tablets taken together?

Claims 1 and 3 require administration of the claimed combination, while claims 2, 4, and 6 require a pharmaceutical composition. Separate tablets may raise different infringement questions from a fixed-dose combination tablet. The patent’s strongest literal composition coverage is directed to a composition containing both active ingredients.

Does a 10 mg hydrocodone and 600 mg ibuprofen product fall within the numerical claims?

Not under the express 20-to-80 parts ibuprofen range when calculated as 10 mg hydrocodone to 600 mg ibuprofen, which is a 1:60 ratio and therefore within the ratio range. It would not fall within claims 5 and 6 because 600 mg exceeds the stated 200-to-400 mg ibuprofen range.

Can an expired patent still block FDA approval?

No. An expired patent cannot block approval or launch based on patent rights. FDA requirements, controlled-substance rules, labeling, and other unexpired patents can still affect approval or commercialization.

Is hydrocodone-ibuprofen subject to the FDA biosimilar pathway?

No. Hydrocodone-ibuprofen is a small-molecule drug combination. Generic versions proceed through the ANDA framework rather than the biosimilar pathway.

References

U.S. Food and Drug Administration. (1997). Vicoprofen hydrocodone bitartrate and ibuprofen tablets: Prescribing information. FDA.
U.S. Patent and Trademark Office. (1986). U.S. Patent No. 4,587,252: Analgesic compositions containing hydrocodone and ibuprofen. U.S. Department of Commerce.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	1267847	⤷ Start Trial
European Patent Office	0186241	⤷ Start Trial
Japan	S61197517	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 4,587,252

Summary for Patent: 4,587,252