US Patent 11,628,200 (Vancomycin + Lysine + N-Acetyl-D-Alanine Stable Aqueous Composition): Claim Scope and U.S. Patent Landscape
US 11,628,200 claims a narrow but operationally specific U.S. composition patent covering a stable aqueous vancomycin formulation that uses lysine and N-acetyl-D-alanine at defined molar ratios, optional polyethylene glycol (PEG) at capped concentrations, and a defined pH range, with dependent claims tightening ratios, PEG identity/amount, pH sub-ranges, stereochemistry of lysine, and stability performance benchmarks at 25°C for at least 3 months.
What the independent claim covers in plain terms
Claim 1 covers a stable aqueous pharmaceutical composition with:
- Vancomycin: ~0.5% w/v
- Lysine: present such that vancomycin:lysine molar ratio is ~1:20
- N-acetyl-D-alanine (NADA): present such that vancomycin:NADA molar ratio is 1:10 to 1:30
- Optional PEG: 0 to 1.8% v/v
- pH: ~4 to 5.53
- Stability is asserted as part of the composition definition, and is later quantified in claims 17–18.
The claim is structured so that product redesign around pH, molar ratios, PEG content, lysine stereochemistry, or the quantified stability window are the primary levers.
Claim-to-coverage map (core infringement variables)
| Technical element |
Claim 1 scope |
Dependent claim tightening |
| Vancomycin concentration |
About 0.5% w/v |
Not further quantified beyond claim 1 in provided dependents |
| Vancomycin:lysine molar ratio |
~1:20 |
Not further tightened in provided dependents |
| Vancomycin:NADA molar ratio |
1:10 to 1:30 |
Claim 2: 1:20 to 1:30 |
| PEG concentration |
0 to 1.8% v/v (optional) |
Claim 4: 1.8% v/v; Claim 5: PEG 400 |
| PEG present? |
Optional (could be 0) |
Claim 3: excludes PEG entirely |
| pH range |
~4 to 5.53 |
Claims 6–14: multiple pH sub-ranges; Claim 9–14: specific pH values including 5.03/5.05/5.06/5.49/5.51/5.53 |
| Lysine stereochemistry |
Lysine unspecified in claim 1 text provided |
Claim 15: D-lysine; Claim 16: L-lysine |
| Stability benchmark |
“stable” in claim 1 |
Claim 17: ≥95% vancomycin remaining after 3 months at 25°C; Claim 18: ≥96–99.5% depending on threshold |
How broad are the independent claim boundaries (pH, ratios, PEG) under U.S. claim construction?
What is likely to be “material” for infringement
Because Claim 1 is defined by numerical ranges and specific excipient identities, U.S. infringement analysis will usually pivot on whether an accused product:
- Uses vancomycin at about 0.5% w/v,
- Contains lysine and NADA at the specified molar ratios,
- Falls in the pH band,
- Either includes PEG within 0 to 1.8% v/v or contains no PEG (and still meets other constraints),
- Meets the “stable” characterization.
pH range is a central fence
Claim 1 covers pH about 4 to 5.53, and dependent claims break this into narrower bands:
- Claim 6: pH 4.0–5.06
- Claim 7: pH 5.06–5.49
- Claim 8: pH 5.49–5.53
- Discrete points: Claims 9–14 cover pH 5.03, 5.05, 5.06, 5.49, 5.51, 5.53
Practical implication: a generic reformulation that uses the same ratio strategy but shifts pH outside 4–5.53 (or avoids the dependent discrete points if the patentee is asserting those) is a plausible design-around. Conversely, if a product formulation naturally lands within those ranges, it increases direct overlap.
PEG presence creates alternative claim routes
Claim 1 is written to allow PEG from 0 to 1.8% v/v. That means:
- A product with no PEG can still fall within claim 1’s express formulation range (Claim 3 is merely a dependent “does not comprise PEG” fallback).
- A product with PEG 400 at 1.8% v/v is captured by dependent claims 4–5 if the rest of the claim elements align.
Practical implication: removing PEG alone may not avoid infringement because claim 1 already includes “0% v/v PEG.” PEG is not a binary element for Claim 1.
Molar ratio fences are the other main control points
- Vancomycin:lysine is ~1:20 (Claim 1)
- Vancomycin:NADA is 1:10 to 1:30 (Claim 1)
- Claim 2 tightens NADA ratio to 1:20–1:30
Practical implication: ratio deviations are likely to be the most direct design-around lever. However, “about” in 1:20 introduces tolerance; litigation will focus on how “about” is construed relative to analytical measurement error, formulation variability, and the patent’s written description support (not provided in the prompt).
What do the dependent claims add: numerical sub-ranges, stereochemistry, and stability endpoints?
Dependent claims that narrow formulation variants
- Claim 2: NADA ratio tightened to 1:20–1:30.
- Claim 3: no polyethylene glycol.
- Claims 4–5: PEG is 1.8% v/v and PEG is PEG 400.
- Claims 6–8: pH partitioned into 4.0–5.06, 5.06–5.49, and 5.49–5.53.
- Claims 9–14: specific pH values 5.03, 5.05, 5.06, 5.49, 5.51, 5.53.
- Claims 15–16: lysine identity as D-lysine vs L-lysine.
Dependent claims that create evidentiary strength: stability as a quantified functional limitation
- Claim 17: stable for ≥3 months at 25°C with ≥95% vancomycin remaining.
- Claim 18: stable for ≥3 months at 25°C with vancomycin remaining thresholds of ≥96%, 97%, 98%, 99%, or 99.5%.
Practical implication: stability endpoints can be a powerful litigation and regulatory differentiation tool because they require empirical proof. If an accused product is chemically similar but degrades faster in the relevant conditions, it may avoid the stability-defined limitations even if it overlaps on excipient ratios and pH. Conversely, if stability studies show the same degradation profile, it strengthens infringement position.
Patent landscape analysis in the U.S.: where US 11,628,200 fits in typical vancomycin formulation estates
Because the prompt provides only the claim set and not the patent’s bibliographic details (assignee, application family, filing date, priority date, or the full specification), a complete “estate” mapping across every related U.S. patent number is not possible from the provided inputs alone. The analysis below focuses on the claim architecture and the standard structure of adjacent IP that typically coexists with aqueous vancomycin stability patents.
How formulation patents cluster around vancomycin instability
Vancomycin aqueous formulations are commonly protected through combinations of:
- Buffer/pH and ionic composition strategies to control hydrolysis or conformational degradation,
- Stabilizing co-solutes/excipients that suppress degradation,
- Container closure and manufacturing steps affecting stability,
- Assay windows and acceptance criteria (like the “≥95% remaining after 3 months at 25°C” style).
US 11,628,200 is specifically an aqueous excipient-stabilized composition with explicit ratio requirements and quantified stability performance.
Common adjacent claim categories that may overlap in litigation
Even without enumerating co-pending patent numbers, this claim set strongly implies overlap risk with U.S. patents in the following buckets:
- Vancomycin + amino acid (lysine) stabilization in aqueous media.
- Vancomycin + N-acetyl-D-alanine stabilization or NADA-containing buffers/co-solutes.
- PEG or other cosolute stabilization of vancomycin in low-to-mid pH solutions.
- pH-specific stability claims around the ~4–5.5 band.
- “Stable for X time at Y temperature” claims with specified remaining drug thresholds.
Key point: because Claim 1’s scope is already broad across PEG presence and pH band (subject to caps), adjacent patents will often compete on either:
- narrower ratio bands,
- particular PEG identity/amount,
- particular pH points/sub-ranges, or
- stability endpoints.
When does US 11,628,200 lose exclusivity or effectively become challengeable?
A precise exclusivity and expiration timeline requires at least:
- filing date and earliest priority date,
- patent term adjustment/extension (if any),
- whether it is tied to any FDA approvals and Orange Book exclusivity categories,
- whether it is method-of-use vs composition (this one is composition),
- and whether any terminal disclaimer or PTA changes apply.
Those bibliographic facts are not provided in the prompt. As a result, an accurate U.S. “expiration date” and “Paragraph IV timing” analysis cannot be completed from the available information.
What are the likely litigation-relevant infringement theories for this claim set?
Direct infringement on formulation composition
To assert direct infringement of Claim 1, the patentee would typically measure:
- vancomycin concentration (targeting “about 0.5% w/v”),
- molar ratio vancomycin:lysine (~1:20),
- molar ratio vancomycin:NADA (1:10 to 1:30),
- PEG presence and amount (0–1.8% v/v, including the special case of PEG 400),
- pH (4–5.53, including specific pH points if those dependent claims are asserted),
- stability outcome at 25°C over at least 3 months, with vancomycin remaining ≥95% or ≥96–99.5%.
Literal infringement sensitivity
- If an accused product misses a ratio or pH boundary, literal infringement weakens.
- If it meets boundaries but fails stability endpoints (claims 17–18), infringement may still be possible for Claim 1 (“stable” in general), but will be harder if stability is treated as a construed limitation with quantified benchmarks.
Doctrine of equivalents risk
“About” (for ratios and concentration) plus broad pH range creates a spectrum of equivalents risk. Design-arounds that move the formulation just slightly outside the numeric constraints still face uncertainty over “about” and measurable equivalents arguments.
Commercial and development implications: where design-arounds are likely to succeed or fail
Highest-leverage design-around levers
Based on claim structure, the main ways to reduce overlap are:
- Shift pH outside 4–5.53 (or avoid dependent discrete points if the enforcement strategy focuses there).
- Change molar ratios, especially vancomycin:NADA and vancomycin:lysine.
- Use different stabilizers while staying clear of NADA and/or lysine at the required ratios.
- Demonstrate stability below the quantified thresholds at 25°C for 3 months, if claims 17–18 are asserted.
Likely “failure modes” for challengers
- Keeping the same pH and ratio framework but merely removing PEG: claim 1 includes PEG = 0.
- Substituting PEG with a different PEG type: dependent claim 5 is PEG 400, but Claim 1 still covers PEG broadly within the capped range.
- Using a similar pH but relying on small differences: dependent claims include multiple pH bands and specific pH numbers, narrowing safe harbor if the formulation targets those values.
What patent estate mapping can be concluded from the claim set alone?
The claim set indicates an estate strategy that is typical for formulation patents:
- Independent claim broadens across PEG presence and wide pH window.
- Dependent claims creates fallback positions at discrete pH values, PEG 400 identity and concentration, and tightened ratio endpoints.
- Stability claims add a functional performance layer that can support enforcement against “same recipe, same behavior” products.
This structure is consistent with a strategy to withstand design-around attempts by adjusting excipient presence or shifting to sub-bands of pH/range.
Key Takeaways
- US 11,628,200 Claim 1 covers an aqueous vancomycin formulation at ~0.5% w/v with vancomycin:lysine ~1:20, vancomycin:N-acetyl-D-alanine 1:10–1:30, PEG optional from 0 to 1.8% v/v, and pH ~4 to 5.53.
- Dependent claims narrow: NADA ratio to 1:20–1:30, PEG-free embodiments, PEG 400 at 1.8% v/v, multiple pH sub-ranges and discrete pH values (5.03/5.05/5.06/5.49/5.51/5.53), D-lysine vs L-lysine, and measured stability at 25°C for 3 months with ≥95% or ≥96–99.5% remaining vancomycin.
- PEG removal alone is not a safe design-around because Claim 1 includes 0% v/v PEG.
- The most direct infringement-risk levers are molar ratios, pH, and stability at 25°C over 3 months.
- A complete U.S. exclusivity/expiration and Orange Book/Paragraph IV timing analysis cannot be produced from the provided prompt inputs because key bibliographic and FDA linkage data are not included.
FAQs
Which formulation variables are most likely to trigger infringement of US 11,628,200?
Vancomycin concentration near 0.5% w/v, vancomycin:lysine ~1:20, vancomycin:N-acetyl-D-alanine 1:10–1:30, pH ~4–5.53, and stability at 25°C for ≥3 months (claims 17–18).
Does removing polyethylene glycol avoid coverage under claim 1?
No. Claim 1 spans 0 to 1.8% v/v PEG, and Claim 3 specifically covers embodiments without PEG.
What is the narrowest vancomycin:N-acetyl-D-alanine ratio claimed?
From the provided claims, Claim 2 narrows vancomycin:NADA to 1:20 to 1:30.
How do the dependent pH claims affect product design?
They carve the pH window into sub-ranges and specific pH points including 5.03, 5.05, 5.06, 5.49, 5.51, and 5.53, increasing overlap risk for formulations landing near these values.
What stability thresholds are claimed at 25°C for 3 months?
Claim 17: ≥95% vancomycin remaining. Claim 18: ≥96%, 97%, 98%, 99%, or 99.5% remaining (as listed in the claim text).
References
- United States Patent 11,628,200 (claims provided in prompt).
