US Patent 9,144,559: Scope, Claim Boundaries, and US Landscape
US Patent 9,144,559 covers a specific once-daily oral pregabalin pharmaceutical composition defined by a tight polymer architecture: a matrix-forming system (polyvinyl acetate + polyvinylpyrrolidone) combined with a swelling agent (crosslinked polyvinylpyrrolidone), plus broad but bounded weight-fraction ranges for each component. The claims are composition-scoped and formulation-scoped; they do not read as device or method-of-use claims beyond the embedded “adapted for once-daily oral dosing” requirement in claim 1 and the “suitable for once-a-day administration” limitation in claim 5.
What does claim 1 actually require (core composition scope)?
Claim 1 elements (all are required)
Claim 1 requires a pharmaceutical composition with the following, in the same product:
- Active ingredient: pregabalin, or a pharmaceutically acceptable complex, salt, solvate, or hydrate of pregabalin.
- Excipients:
- Matrix forming agent comprises:
- polyvinyl acetate (PVAce) and polyvinylpyrrolidone (PVP)
- Swelling agent comprises:
- crosslinked polyvinylpyrrolidone (cl-PVP)
- Dosage regimen/adaptation: the composition is “adapted for once-daily oral dosing.”
- Weight-fraction ranges (absolute wt% of the final composition):
- pregabalin: 5% to 60%
- matrix forming agent: 5% to 45%
- swelling agent: 15% to 70%
Practical boundary implications
- The product must use both polymer roles at once:
- PVAce + (non-crosslinked) PVP as the matrix-forming component
- cl-PVP specifically as the swelling component
- The swelling agent fraction is unusually broad (15% to 70%), which widens infringement risk for compositions that emphasize gel/swelling-driven release.
- The pregabalin loading is also broad (5% to 60%), which expands the claim to multiple fill strategies.
How do dependent claims narrow the polymer ratios?
Claim 2 narrowing (midrange polymer fractions)
Claim 2 tightens only the component ranges already recited in claim 1:
- Matrix forming agent: about 20% to about 35% of composition (wt%)
- Swelling agent: about 20% to about 55% of composition (wt%)
This is a “sweet spot” band within claim 1’s wider ranges.
Claim 3 and claim 4 (PVAce fraction within the matrix)
Claims 3 and 4 define the internal composition of the matrix forming agent (PVAce + PVP). Importantly, they use a ratio framed as a percentage of the combined matrix-former weight, not of the total formulation.
- Claim 3: PVAce is about 60% to about 90% by weight of (PVAce + PVP)
- Claim 4: PVAce is about 70% to about 90% by weight of (PVAce + PVP)
These dependents materially narrow compositions where PVP dominates over PVAce inside the matrix.
Claim 5: separate formulation claim with explicit matrix and cl-PVP bounds
Claim 5 converts the concept into a “once-a-day” formulation with more explicit composition bookkeeping:
- Pregabalin: 5% to 60% of total formulation
- Matrix (PVAce + PVP):
- matrix amount: 20% to 35% wt% of total formulation
- PVAce portion: 70% to 90% wt% of (PVAce + PVP)
- Crosslinked PVP: 10% to 35% wt% of total formulation
Claim 6: tighter cl-PVP band
Claim 6 narrows cl-PVP:
- cl-PVP: 20% to 30% wt% of total formulation
Dependency structure and what it does to infringement coverage
- A product can infringe claim 5/6 even if it lands only within those more specific ranges, without needing to hit claim 1’s broad boundaries beyond what claim 5 already enforces.
- The “PVAce within matrix” limitation is a key design knob:
- Claim 5 requires PVAce 70% to 90% of the matrix (PVAce + PVP), which limits formulations using substantial free PVP.
- The “cl-PVP wt% of total formulation” limitation makes swelling-agent loading a direct claim parameter.
What are the practical “claim scope hotspots” for product design?
The claims create three hotspots where small formulation shifts drive claim coverage:
1) Which polymer is crosslinked
- Only crosslinked PVP qualifies as the swelling agent in the claim architecture.
- Substituting non-crosslinked PVP as the swelling agent would not meet the “crosslinked” requirement.
2) PVAce:PVP inside the matrix
- Claim 1 does not set a minimum PVAce fraction inside the matrix; it only says the matrix forming agent comprises polyvinyl acetate and polyvinylpyrrolidone.
- Claim 3/4/5 add internal structure requirements that can be dispositive:
- Claim 5 forces PVAce at 70% to 90% of (PVAce + PVP).
3) Absolute wt% bands of each functional component
- Claim 1 uses “matrix forming agent” (5% to 45%) and “swelling agent” (15% to 70%) as absolute component totals.
- Claim 5 translates to:
- matrix total: 20% to 35%
- cl-PVP total: 10% to 35% (and claim 6: 20% to 30%)
What is the likely release-mechanism linkage, based on claim language?
The claims do not recite a dissolution profile, Cmax/Tmax target, or release kinetics. They rely on excipient function labels:
- Matrix forming agent: PVAce + PVP
- Swelling agent: crosslinked PVP
The practical interpretation is a swelling-in-matrix oral controlled release system suitable for once-daily dosing, where the cl-PVP swells to facilitate water uptake and matrix disruption or diffusion modulation. That said, infringement is driven by composition and regimen suitability, not by explicitly claimed in vitro data.
How broad is the “pregabalin” coverage?
Claim scope includes:
- pregabalin itself
- pharmaceutically acceptable complex/salt/solvate/hydrate of pregabalin
So, the claim can cover multiple pregabalin forms as long as the polymer composition and dosing adaptation limits are met.
How does “adapted for once-daily dosing” constrain infringement?
- Claim 1: “adapted for once-daily oral dosing”
- Claim 5: “suitable for once-a-day administration”
This is typically a regimen suitability limitation, which can be met by formulation design intended for once-daily administration (and often evidenced through dosage form design, label dosing scheme, or release behavior). The claims do not require a specific dissolution test in the text provided, so the scope hinges on whether the formulation is made and used as a once-daily product.
Where does US 9,144,559 sit in the broader pregabalin patent landscape?
Key positioning
US 9,144,559 is best characterized as a formulation architecture patent for extended/controlled oral delivery of pregabalin using a polymer matrix and a swelling agent system. Its novelty, as reflected by the claim language you provided, sits in the combination of:
- PVAce + PVP matrix
- cl-PVP swelling
- once-daily dosing suitability
- explicit wt% bounds for pregabalin and functional polymers
Landscape implications for competitors
For US generic or follow-on developers:
- Products with a different polymer backbone (e.g., different matrix polymers or swelling agents not based on crosslinked PVP) can avoid claim 1/5 composition elements.
- Products with the same general “matrix + swelling” approach still face risk if they incorporate crosslinked PVP and keep within the claimed quantitative bands.
For branded/sustained-release entrants:
- The internal matrix composition requirements (especially claim 5’s PVAce 70% to 90% of (PVAce + PVP)) can force either reformulation around these thresholds or deliberate selection of an alternative swelling agent.
Claim-by-claim scope matrix (what must be present to infringe)
| Claim |
Must contain pregabalin |
Must contain matrix former (PVAce + PVP) |
Must contain cl-PVP swelling agent |
Once-daily suitability |
Quantitative boundaries in your text |
| 1 |
Yes |
Yes |
Yes |
Yes (“adapted”) |
pregabalin 5-60 wt%; matrix 5-45 wt%; swelling 15-70 wt% |
| 2 |
Yes |
Yes |
Yes |
Yes |
matrix 20-35 wt%; swelling 20-55 wt% |
| 3 |
Yes |
Yes |
Yes |
Yes |
PVAce 60-90 wt% of (PVAce+PVP) |
| 4 |
Yes |
Yes |
Yes |
Yes |
PVAce 70-90 wt% of (PVAce+PVP) |
| 5 |
Yes |
Yes |
Yes |
Yes (“suitable”) |
pregabalin 5-60 wt%; matrix 20-35 wt%; PVAce 70-90 wt% of (PVAce+PVP); cl-PVP 10-35 wt% |
| 6 |
Yes |
Yes |
Yes |
Yes |
cl-PVP 20-30 wt% |
What are the design-around levers that follow directly from the claim text?
Even without referencing external literature, the text itself implies several clear levers:
-
Remove or replace crosslinked PVP as the swelling agent.
If swelling is achieved using non-crosslinked PVP, another crosslinked polymer, or a different swelling material, the swelling-agent element likely fails.
-
Change the internal matrix formulation outside the PVAce fraction limits.
If PVAce falls below 70% (claim 5) or below 60% (claim 3) of (PVAce + PVP), dependent claims 3/4/5 may not read.
-
Move outside absolute wt% bands for matrix and swelling totals.
- To avoid claim 2: matrix 20-35 wt% and swelling 20-55 wt%
- To avoid claim 5/6: matrix 20-35 wt% and cl-PVP 10-35 wt% (and 20-30 wt% for claim 6)
-
Shift pregabalin loading out of 5-60 wt%.
This is a practical lever but can conflict with dose uniformity and tablet core constraints.
Key Takeaways
- US 9,144,559 is composition-anchored: infringement turns on having pregabalin plus a PVAce/PVP matrix plus crosslinked PVP swelling agent, with once-daily suitability.
- Claim 1 is broad on overall loading but specific on polymer roles: matrix former is PVAce+PVP; swelling agent is crosslinked PVP; once-daily adaptation is embedded.
- Claims 5 and 6 are the tightest quantitative targets:
- PVAce is 70% to 90% of the (PVAce + PVP) matrix portion
- matrix total is 20% to 35% of the formulation
- cl-PVP is 10% to 35% (claim 5) and 20% to 30% (claim 6)
- Competitor risk concentrates in formulations that use cl-PVP swelling with a predominantly PVAce matrix and fall inside the defined wt% bands for total matrix and cl-PVP.
FAQs
1) Is US 9,144,559 limited to pregabalin only, or does it cover salts/solvates/hydrates?
It covers pregabalin plus pharmaceutically acceptable complexes, salts, solvates, and hydrates.
2) What polymer is uniquely required as the swelling agent?
Crosslinked polyvinylpyrrolidone.
3) Does the patent require a specific mechanism or in vitro release profile?
No release kinetics or test parameters are stated in the claim text you provided; the scope is defined by composition and once-daily suitability language.
4) Which dependent claims materially narrow the polymer selection?
Claims 3, 4, 5, and 6 narrow the quantitative distribution of PVAce within the PVAce+PVP matrix and narrow cl-PVP loading.
5) What is the key quantitative “tripwire” for claim 5/6 products?
cl-PVP wt% (10% to 35% in claim 5; 20% to 30% in claim 6) and PVAce at 70% to 90% of the matrix-former portion.
References
[1] United States Patent 9,144,559. Claimed subject matter and claim language as provided in the user prompt.
