United States Patent US 8,309,127: Scope, Claims, and Patent Landscape for the Ibuprofen-Famotidine Immediate-Release Bilayer/Table-in-Tablet Formulation
What does US 8,309,127 claim in scope?
US 8,309,127 is directed to an immediate-release (IR) solid oral dosage form that combines:
- Ibuprofen: 750 mg to 850 mg per tablet (first layer)
- Famotidine: 24 mg to 28 mg per tablet (second layer)
- Layering architecture: direct physical contact between APIs, with specific limits on where and how contact occurs
- Release timing: ibuprofen and famotidine begin release at about the same time
- No enteric coating and no sustained-release formulation for either API layer
- Exclusion of a specific prior art configuration: famotidine is not “barrier coated famotidine multiparticulates dispersed in an ibuprofen matrix”
- Stability thresholds under specified accelerated and long-term conditions
- A measured/controlled direct-contact surface area limit in dependent claim set
The claims split into two main independent claim tracks:
- Claim set around thermal stress at 40°C/75% RH (claims 1-13)
- Claim set around room temperature stability plus an explicit surface-area control (claims 14-30)
Core quantitative claim elements
| Claim element |
Values recited |
Where it appears |
| Ibuprofen dose |
750–850 mg |
Independent claims 1 and 14 |
| Famotidine dose |
24–28 mg |
Independent claims 1 and 14 |
| Dosage form |
Tablet; optionally table-in-tablet |
Independent claims 1 and 14; dependent 12, 13, 29, 30 |
| Immediate-release |
IR; not enterically coated; not sustained release |
Independent 1, 14 |
| Layering |
First layer and second layer; APIs in direct contact |
Independent 1, 14 |
| “Table-in-tablet” condition |
First layer completely surrounds second layer |
Independent 1, 14 |
| Release simultaneity |
Ibuprofen and famotidine release begins at about same time |
Independent 1, 14 |
| Barrier multiparticulate exclusion |
Famotidine is not barrier coated famotidine multiparticulates dispersed in an ibuprofen matrix |
Independent 1, 14 |
| Contact limitation metric |
Direct physical contact surface area ≤ 130 mm² |
Independent 14 (and not in independent 1) |
| Storage condition |
40°C/75% RH for 1/3/6 months |
Claims 1-11 |
| Storage condition |
Room temperature for 3 to 36 months |
Claims 14-28 |
| Stability standard |
“At least 90%” or “at least 95%” remains (ibuprofen and famotidine separately) |
Dependent claims 2-11, 15-28 |
How broad is claim 1 (40°C/75% RH track)?
Claim 1 is the broad independent “anchor” on accelerated stability. It covers any tablet meeting all of these constraints simultaneously:
- Two-layer immediate-release tablet with:
- first layer containing 750–850 mg ibuprofen
- second layer containing 24–28 mg famotidine
- Direct contact between APIs
- No enteric coating and no sustained release formulation of the composition or either layer/API
- Release timing: ibuprofen and famotidine release begins “at about the same time”
- Exclusion: famotidine is not a formulation of “barrier coated famotidine multiparticulates dispersed in an ibuprofen matrix”
- Stability: after 40°C and 75% RH for one month:
- ≥90% of initial ibuprofen remains
- ≥90% of initial famotidine remains
Dependent claim ladder under claim 1
Claim 1 is tightened via yield targets and longer storage windows.
Ibuprofen stability (claims 2-6)
- 1 month: ≥95% (claim 2)
- 3 months: ≥90% (claim 3) and ≥95% (claim 4)
- 6 months: ≥90% (claim 5) and ≥95% (claim 6)
Famotidine stability (claims 7-11)
- 1 month: ≥95% (claim 7)
- 3 months: ≥90% (claim 8) and ≥95% (claim 9)
- 6 months: ≥90% (claim 10) and ≥95% (claim 11)
Dosage-form embodiment (claims 12-13)
- Table-in-tablet (claim 12)
- Bilayer tablet (claim 13)
Claim 1 practical “lock-in” points
Even though the claim text is structured as a set of constraints, three operate like gatekeepers:
- Direct contact between APIs (not merely co-displacement in separate compartments)
- Immediate-release without enteric or sustained release for the APIs/layers
- Stability in accelerated conditions at levels ≥90% (or ≥95% in dependents)
Those elements jointly narrow the usable design space more than the dose ranges do.
How broad is claim 14 (room temperature track plus surface contact limit)?
Claim 14 is an independent claim that combines:
- all claim 1 style constraints (doses, tablet form, immediate release, direct contact, no enteric/no sustained release, same-time release onset, exclusion of barrier multiparticulate dispersed in ibuprofen matrix)
- plus two key modifications:
- Direct physical contact surface area does not exceed 130 mm²
- Stability is tested at room temperature (not 40°C/75% RH) across a longer duration range
Claim 14 stability anchor
After room temperature storage for 3 months:
- ≥90% ibuprofen initially present remains
- ≥90% famotidine initially present remains
Dependent claims 15-28: tightening the room-temperature window and targets
Ibuprofen (claims 15-21)
- 3 months: ≥95% (claim 15)
- 6 months: ≥90% (claim 16) and ≥95% (claim 17)
- 9 months: ≥90% (claim 18)
- 12 months: ≥90% (claim 19)
- 24 months: ≥90% (claim 20)
- 36 months: ≥90% (claim 21)
Famotidine (claims 22-28)
- 3 months: ≥95% (claim 22)
- 6 months: ≥90% (claim 23) and ≥95% (claim 24)
- 9 months: ≥90% (claim 25)
- 12 months: ≥90% (claim 26)
- 24 months: ≥90% (claim 27)
- 36 months: ≥90% (claim 28)
Dosage-form embodiment (claims 29-30)
- Table-in-tablet (claim 29)
- Bilayer tablet (claim 30)
What is the claim-to-technology “reading” for design-arounds?
Within this patent, infringement risk concentrates in formulations that satisfy every element in the claim set, not just API pairing.
The design pressure: direct contact + immediate release + stability
The patent is built around a specific, difficult proposition: keep two APIs in direct physical contact while still achieving:
- simultaneous release onset in an immediate-release context
- no enteric or sustained-release behavior
- chemical/physical integrity metrics under humidity/temperature stress
The explicit exclusion: barrier-coated famotidine multiparticulates dispersed in an ibuprofen matrix
Any product that uses a structure where:
- famotidine is barrier coated,
- in multiparticulate form,
- and dispersed within an ibuprofen matrix,
is pushed outside the claim language.
This exclusion targets a category of mixed microstructured architectures rather than merely excluding “famotidine” products generally.
The additional limiter in claim 14: direct contact surface area ≤130 mm²
Where claim 1 only requires “direct physical contact,” claim 14 adds a quantitative upper bound on surface area of direct physical contact.
That creates a measurement-based infringement constraint for any “similar but contact-reduced” designs.
Where is the enforceable scope inside the claim set?
The most enforceable elements are the ones repeated across independent claim language (1 and 14):
- Dose ranges for both actives
- Two-layer or table-in-tablet with direct contact
- IR and no enteric/no sustained release
- Same-time release onset
- Exclusion of barrier coated famotidine multiparticulates dispersed in ibuprofen matrix
The dependent claims then add “gradient” enforcement through:
- storage conditions and time-length
- stability thresholds (90% vs 95%)
- contact surface area limit (in claim 14 only)
- formulation type limitations (bilayer/table-in-tablet)
Patent landscape implications (what this patent blocks or shapes)
A reliable landscape inference from claim scope is possible without using prosecution details:
1) It occupies the “combined ibuprofen + famotidine IR direct-contact layered tablet” design corner
To avoid crossing into literal coverage, competing products must change at least one gatekeeper element:
- eliminate direct contact (for example, introduce a non-contact separation layer, even if that layer is not “enteric”)
- eliminate immediate release behavior for one API (enteric or sustained-release mechanisms)
- change the dose ranges
- change the formulation so famotidine is barrier coated multiparticulates dispersed in an ibuprofen matrix (note: this is the opposite of avoiding; but the exclusion language means that that specific architecture is not within the claim)
2) It prioritizes stability performance as part of claim scope
This is not a “process-only” stability patent; the stability is part of claimed composition structure by required performance under storage conditions.
That typically makes design-around harder:
- even if a product structurally seems similar, it must meet the claimed stability metrics to infringe dependent performance-ladder claims
- a competitor can attempt to exceed stability thresholds while still changing other elements, but claim language makes “product behavior under defined stress” an infringement axis
3) It sets a measurable contact limit for room-temperature claims (claim 14 family)
Surface area measurement (≤130 mm²) becomes a factual and technical question. Products that use “direct contact” but reduce the actual interface below the limit can be argued as outside claim 14 while possibly still risking claim 1 if other conditions align.
Key claim map (what each independent claim covers)
| Element |
Claim 1 |
Claim 14 |
| Ibuprofen dose |
750-850 mg |
750-850 mg |
| Famotidine dose |
24-28 mg |
24-28 mg |
| Tablet format |
Tablet; table-in-tablet option |
Tablet; table-in-tablet option |
| Layering |
First layer in contact with second layer |
Same |
| Direct contact requirement |
Yes |
Yes |
| Direct contact surface area cap |
Not stated |
≤130 mm² |
| Enteric/sustained release |
Neither composition/layers are enterically coated or sustained release |
Same |
| Release onset |
Begins to occur at about same time |
Same |
| Exclusion |
No barrier coated famotidine multiparticulates dispersed in ibuprofen matrix |
Same |
| Stability test anchor |
40°C/75% RH |
Room temperature |
| Stability anchor duration |
1 month |
3 months |
| Stability threshold |
≥90% ibuprofen and ≥90% famotidine |
≥90% ibuprofen and ≥90% famotidine |
What does the claim set imply about competitor product positioning?
A competitor considering an ibuprofen-famotidine combination tablet must treat four technical variables as simultaneously constrained:
- Dose matching (not just “about” within formulation tables, but within the claimed numeric bands)
- Layer architecture supporting direct contact without enteric/sustained release
- Release onset synchronization (“about the same time”)
- Stability under the recited storage conditions, especially humidity/temperature stress for the claim 1 track
The patent also creates a negative constraint in the explicit exclusion clause targeting barrier-coated famotidine multiparticulates dispersed in ibuprofen matrix. That pushes competitors toward either:
- different structural arrangements for famotidine (non-barrier-coated multiparticulates or different physical form), or
- different spatial/interaction design so that it does not match the excluded architecture.
Key Takeaways
- US 8,309,127 claims an immediate-release, two-layer (or table-in-tablet) ibuprofen-famotidine tablet with API direct physical contact, same-time release onset, and no enteric/no sustained release.
- The enforceable claim backbone is dose ranges plus direct contact + IR constraints + same-time release + exclusion of a specific famotidine barrier-multiparticulate-in-ibuprofen-matrix architecture.
- Claim 14 adds a quantitative limiter: direct physical contact surface area ≤130 mm², and it uses room-temperature stability up to 36 months.
- The dependent claims monetize performance via 90%/95% remaining drug under defined storage conditions, creating a compliance requirement tied to stability results.
FAQs
1) Does the patent require enteric coating to avoid infringement?
No. The claims require none of the composition or layers/APIs to be enterically coated and none to be formulated for sustained release.
2) Are the dose ranges flexible?
The claims specify 750–850 mg ibuprofen and 24–28 mg famotidine; falling outside those numeric ranges avoids literal coverage of the independent claims.
3) What is the biggest structural discriminator between claim 1 and claim 14?
Claim 14 adds the direct physical contact surface area limit of ≤130 mm² and uses room-temperature stability as the anchor, while claim 1 uses 40°C/75% RH.
4) What specific formulation is excluded from claim coverage?
The claims exclude formulations where famotidine is barrier coated multiparticulates dispersed in an ibuprofen matrix.
5) What stability metrics matter most for infringement risk?
For claim 1, the anchor is ≥90% ibuprofen and ≥90% famotidine after 1 month at 40°C/75% RH. For claim 14, the anchor is ≥90% ibuprofen and ≥90% famotidine after 3 months at room temperature, with additional dependent thresholds extending to 36 months.
References
[1] United States Patent US 8,309,127.
