United States Patent 5,087,454 for Ibuprofen Compressed Tablets: What the Claims Cover and How to Map the Patent Landscape

Executive summary: U.S. Patent 5,087,454 covers a narrow, process-and-composition-controlled dissolution-stabilized ibuprofen compressed tablet/caplet. The independent claim is anchored on: (i) a core composition range of 50–70 wt% ibuprofen, (ii) wet granulation using an excipient system that includes starch, (iii) a compression mix that also includes starch, and (iv) a specific dissolution/aging stabilization package using croscarmellose sodium at ~1–2 wt% in both the wet granulation and the compression mix, plus sodium lauryl sulfate at ~0.05–0.15 wt% in the compression mix. This claim structure creates clear design-around logic: move outside either the ibuprofen core range, the croscarmellose placement/levels, or the sodium lauryl sulfate level, while maintaining a starch-based wet granulation/compression mix framework.

What does US Patent 5,087,454 claim for ibuprofen tablets and what is the technical scope?

Short answer: The patent claims a starch-based wet granulated ibuprofen tablet with dissolution profile improvement that is stable on aging, achieved by dual-location incorporation of croscarmellose sodium (into both wet granulation and compression mix) and by adding sodium lauryl sulfate into the compression mix in defined ranges.

Claim 1 structure (element-by-element mapping)

Below is a claim-scope breakdown aligned to infringement and validity risk.

A. Dosage form and core composition

Compressed tablet/caplet (implied oral solid dosage form intended for dissolution testing).
Ibuprofen core wt% range: about 50% to about 70% by weight based on tablet/caplet core weight.

This is a quantitative limitation. A product at ~49.9 wt% or ~70.1 wt% is outside the explicit range.

B. Wet granulation process requirement

The tablet core is formed by wet granulating ibuprofen with an excipient that comprises starch to provide a dry base granulation.

This ties the claim to wet granulation and a starch-containing excipient system for the granulation step.

C. Compression mix preparation

A compression mix is formulated containing:
- the dry base granulation, and
- an excipient that comprises starch.

This ties the formulation to a starch-containing compression stage.

D. Dissolution and aging stabilization improvement package

“Improved dissolution profile maintained stable on aging” is achieved by:
- (1) separately incorporating into each of the wet granulation and the compression mix:
  - croscarmellose sodium at about 1% to about 2% by weight based on core weight of the compressed tablet, and
- (2) incorporating into the compression mix:
  - sodium lauryl sulfate at about 0.05% to about 0.15% by weight based on core weight.

The phrase “separately incorporating” makes location an enforceable boundary. A formulation that includes croscarmellose sodium only in the compression mix (not in the wet granulation) should not meet the literal “each of” requirement, depending on claim construction and doctrine-of-equivalents posture.

What the claim implies about functional performance

The claim’s improvement is functional (“improved dissolution profile maintained stable on aging”), but the operative limitations are composition and process-based. In litigation, performance evidence is often used to support enablement, written description, and nonobviousness, but infringement is usually determined by meeting the compositional/process parameters.

How strong is the patent estate for ibuprofen dissolution stability: is US 5,087,454 narrow or broad?

Short answer: The estate is narrowly drafted around a specific dissolution/aging stabilization excipient logic with hard numeric ranges and dual-stage incorporation requirements.

Breadth drivers (features that narrow scope)

Hard numeric limits: ibuprofen 50–70 wt%, croscarmellose sodium 1–2 wt% and sodium lauryl sulfate 0.05–0.15 wt%.
Starch requirement at two stages: starch in the wet granulation excipient system and in the compression mix excipient system.
Wet granulation requirement: excludes direct compression products unless equivalents are argued.
Location requirement: croscarmellose sodium is required in both wet granulation and compression mix.

Where competitors have flexibility

Even with those constraints, design options remain:

Change starch system (different starch types) may still satisfy “comprises starch” if any starch component is present.
Change other excipients not specified in the claim.
Alter granulation solvent system, drying steps, and equipment if not constrained elsewhere.
Modify croscarmellose sodium placement (only in one stage) or level (below ~1% or above ~2% depending on rounding and assay practice).

Equivalents exposure

A party could attempt a doctrine-of-equivalents argument if croscarmellose sodium is effectively present in both stages (for example, a granulation that uses a mixture where croscarmellose enters during wet mixing but is weighed into the compression stage differently). Conversely, the “separately incorporating into each of” language gives the patentee room to argue that mere presence in the final blend is not enough.

Which excipient combinations in ibuprofen tablets would likely infringe US 5,087,454?

Short answer: Products that match all of these simultaneously are at highest literal risk:

ibuprofen core 50–70 wt%
wet granulation with starch to form dry base granulation
compression mix with starch
croscarmellose sodium 1–2 wt% in both wet granulation and compression mix
sodium lauryl sulfate 0.05–0.15 wt% in the compression mix

Infringement mapping table (literal coverage checklist)

Claim element	Literal requirement	High-risk product design target
Dosage form	compressed tablet/caplet	oral solid compressed ibuprofen
Ibuprofen level	~50–70 wt% of core	assay within range
Granulation method	wet granulate	aqueous or other wet process
Granulation excipient	starch is present	starch in granulation formulation
Compression mix excipient	starch present	starch in final mix
Croscarmellose sodium	1–2 wt% in each of wet granulation and compression mix	add to both stages
Sodium lauryl sulfate	0.05–0.15 wt% in compression mix	add to compression mix only

How can a generic manufacturer design around US 5,087,454 claims?

Short answer: The cleanest design-arounds are to break one of the enforceable boundaries: core ibuprofen wt% range, starch-in-two-stages, wet granulation, dual-stage croscarmellose placement, or sodium lauryl sulfate level.

Most direct design-around levers

Move out of the croscarmellose placement requirement
- Put croscarmellose sodium only in the compression mix (avoid adding it during wet granulation).
Move out of the croscarmellose level range
- Use <1 wt% or >2 wt% (assay- and rounding-sensitive).
Remove or reduce sodium lauryl sulfate
- Use <0.05 wt% or >0.15 wt%, or exclude it entirely.
Change granulation route
- Use direct compression or other non-wet granulation methods (if feasible for performance).
Change starch inclusion
- Exclude starch from the wet granulation excipient and/or the compression mix excipient (note the claim says “comprises starch,” so complete exclusion is what matters).

Design-around risk areas

Products that still use wet granulation and both-stage excipient systems can still be captured if they meet the ranges.
If croscarmellose is added at any point during wet granulation, it may still satisfy “incorporating into the wet granulation.”

What patents protect the same ibuprofen dissolution-stabilized tablet concept around US 5,087,454?

Short answer: Using the claim’s “anchor features” (ibuprofen 50–70 wt%, starch wet granulation, croscarmellose dual-stage at 1–2%, sodium lauryl sulfate 0.05–0.15%), the patent landscape typically clusters into:

excipient-based dissolution stabilizers,
disintegrant and surfactant combination patents,
and process patents around wet granulation/compression mix designs.

However, a complete, accurate landscape requires the patent family members, assignees, publication history, and relevant cited references tied to U.S. Patent 5,087,454. Those bibliographic and citation details are not provided in the prompt.

When does exclusivity expire and can a generic launch without infringing US 5,087,454?

Short answer: The exclusivity for the patent depends on the patent’s filing date, issuance date, and any term adjustments or extensions. Those are not provided, so the expiration timeline cannot be computed from the claim text alone.

What patent litigation risk exists for ibuprofen generics relative to US 5,087,454?

Short answer: Litigation risk is determined by:

whether the accused product meets the specific numeric and placement limitations, and
whether the patent has been litigated or cited in Paragraph IV or related suits.

Those litigation facts are not provided, so a specific risk assessment tied to “which companies” or “which cases” cannot be produced without introducing unsupported claims.

How do the claim’s process and excipient placement limitations affect FDA generic approval risk?

Short answer: FDA approval under an ANDA can occur without establishing a clean patent freedom-to-operate position. For infringement, the critical issue is whether the generic’s manufacturing and formulation match the claim’s two-stage croscarmellose and the compression mix sodium lauryl sulfate ranges.

Practical regulatory-to-IP mapping

If an ANDA relies on the same dissolution strategy, the likelihood of matching the claim increases.
If the ANDA uses different disintegrant placement or surfactant level, literal infringement may be avoided even if dissolution acceptance is achieved.

What formulations are protected by US 5,087,454 beyond the single claim?

Short answer: The provided claim language already covers a defined product family. Broader coverage, dependent claims, and additional independent claims cannot be analyzed without the full claim set and specification disclosure, which are not supplied.

Key Takeaways

U.S. Patent 5,087,454 claims a starch-based wet granulated ibuprofen compressed tablet/caplet where dissolution and aging stability are tied to a specific excipient package.
The claim is narrow because it requires all of:
- ibuprofen core 50–70 wt%,
- starch in both wet granulation and compression mix,
- croscarmellose sodium 1–2 wt% in both stages (wet granulation and compression mix),
- sodium lauryl sulfate 0.05–0.15 wt% in the compression mix.
The strongest design-arounds are to break an enforceable boundary: croscarmellose placement, croscarmellose range, sodium lauryl sulfate range, wet granulation route, or starch inclusion at the required stages.

FAQs

1) Does US 5,087,454 require croscarmellose sodium in both wet granulation and compression mix for infringement?
Yes. The claim states “separately incorporating into each of the wet granulation and the compression mix” within 1–2 wt% ranges.

2) If a tablet has croscarmellose sodium only in the final blend, is it outside the claim?
It would not meet the literal “each of” requirement if croscarmellose is absent from the wet granulation stage.

3) Can a product with ibuprofen slightly below 50 wt% avoid infringement?
It would fall outside the claimed ibuprofen core range as written.

4) Is sodium lauryl sulfate required only in the compression mix?
Yes. The claim limits sodium lauryl sulfate inclusion to the compression mix at 0.05–0.15 wt%.

5) Does the claim cover direct compression tablets?
Not on its face, because it requires a wet granulation step.

References

US Patent 5,087,454 (claim 1 as provided).

Details for Patent: 5,087,454

Summary for Patent: 5,087,454