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Patent landscape, scope, and claims: |
Executive summary
US Drug Patent 10,849,956 claims a stable aqueous vancomycin composition protected by combining N-acetyl-D-alanine with pH 4.5-5.5 and/or an amino acid, in specific concentration (0.5-5% w/V vancomycin), and with defined stability endpoints at 25°C (notably ≥90% vancomycin remaining at ~10 weeks; and for a lysine embodiment, ≥85% at 3–12 months, with a tighter ≥90% at 12 months). The claim set is structured to capture (i) broad “stable aqueous + N-acetyl-D-alanine” compositions and (ii) narrower, product-like formulations specifying L-lysine, PEG/organic solvent (example: ~1.8% V/V PEG), molar ratios (1:1 to 30:1; amino acid:vancomycin 1:1 to 20:1), and assay method (LC per USP 36-NF 31).
Note: A complete patent-landscape assessment (family members, prosecution history, priority chain, other US patents in the same portfolio, Examiner citations, or litigation/Orange Book status) cannot be produced from the claim text alone. The analysis below is limited to claim scope and practical infringement boundaries derivable from the provided claims.
US Patent 10,849,956: what is claimed for stable aqueous vancomycin with N-acetyl-D-alanine
The core invention is a composition claim directed to stability rather than a new vancomycin derivative. The claims require:
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Matrix: stable aqueous pharmaceutical composition
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Actives/components:
- vancomycin at about 0.5–5% w/V
- N-acetyl-D-alanine
- and either:
- pH 4.5–5.5, and/or
- an amino acid (defined in dependent claims)
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Stability endpoint:
- At ~25°C, stable for at least ~10 weeks (claim 1) with ≥90% vancomycin remaining at 10 weeks
- Additional dependent/narrow compositions at 3 months and 12 months, with ≥85% and ≥90% endpoints (claims 12, 18, 19)
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Assay constraint: vancomycin remaining measured by liquid chromatography per USP 36-NF 31 (claims 4, 11, 17, 24)
Claim 1 as the breadth anchor
Claim 1 is the broadest independent claim provided. It is notable for being permissive on “stabilizing conditions”:
- It requires pH 4.5–5.5 and/or the composition comprises an amino acid.
- That means a product that meets stability and composition requirements while relying on pH alone can still fall within claim 1; alternatively, an amino-acid-reliant formulation can also qualify, assuming the “and” conditions (vancomycin + N-acetyl-D-alanine + stability endpoint) are met.
Claims 2, 5, 6, 7 as claim narrowing by selection
- Claim 2 narrows to pH 4.5–5.5.
- Claim 5 narrows to formulations that comprise an amino acid.
- Claim 6 narrows further by enumerating amino acids (D- and L- forms; includes D- and L-lysine and ornithine, and D-forms of alanine/serine/leucine/valine plus L-arginine).
- Claim 7 narrows to L-lysine.
Claims 3 and 10 as claim narrowing by molar ratio
- Claim 3: N-acetyl-D-alanine : vancomycin ~1:1 to 30:1.
- Claim 10: (dependent on claim 5) amino acid : vancomycin ~1:1 to 20:1.
These ratio ranges act as formulation gates. Competitors that choose different stoichiometry can attempt to design around even if stability is similar.
Which stability endpoints at 25°C drive the infringement analysis for 10,849,956
The patent is anchored on quantified stability. This shifts the infringement question toward testing and formulation design.
What does claim 1 require at 25°C?
- Stability duration: at least ~10 weeks at ~25°C
- Potency/remaining amount: ≥90% vancomycin remaining at ~10 weeks
- Test method: LC per USP 36-NF 31 when the claim includes that limitation (claims 4 and 11)
What does the lysine embodiment require at 25°C?
The dependent formulation set specifies a more product-like window (3 and 12 months), with different thresholds.
Claims 12 and 18 (core lysine independent + variations)
Both describe:
- vancomycin at 0.5–5% w/V
- N-acetyl-D-alanine
- L-lysine
- stability at 25°C for either:
- ≥3 months with ≥85% at 3 months, or
- ≥12 months with ≥85% at 12 months
Claim 19 (tightens the 12-month endpoint)
- At about 12 months, vancomycin remaining is ≥90%.
So, if a generic or alternative formulation meets only the weaker threshold (≥85%) at 12 months, it could still potentially fall into claims 12 or 18 but not claim 19.
Practical consequence for design-around
- If a competitor can achieve stability by changing pH, ratio, amino-acid choice, solvent system, or by testing variability, they may avoid meeting the specific ≥90% at 10 weeks and/or ≥90% at 12 months thresholds required by the relevant dependent claims.
What pH range is required, and how does “pH and/or amino acid” change the risk profile
Claim 1’s “pH 4.5–5.5 and/or amino acid” structure
Claim 1 requires:
- pH 4.5–5.5 and/or the composition comprises an amino acid.
This is a key scope feature. It creates multiple infringement paths:
- Path A (pH-only): formulate vancomycin + N-acetyl-D-alanine in water with pH 4.5–5.5 and achieve the stability endpoint without adding an amino acid.
- Path B (amino-acid-only): keep pH outside 4.5–5.5 if the claim language is satisfied by having an amino acid (but still must also meet stability and the rest of claim 1’s required elements).
Dependent claims increase certainty
- Claims 2, 13, 20 require pH about 4.5–5.5.
- A formulation outside that range could attempt to evade those dependents, but would still face claim 1 if it contains an amino acid and meets the stability endpoints.
What amino acids are covered, and which are most leverageable for design-around
The explicit amino acid list (claim 6) is limited but still broad across common stereoisomers and side-chain classes.
Enumerated amino acids in claim 6
The covered amino acids are:
- D-Alanine, D-Serine, D-Leucine, D-Valine
- L-Lysine, D-Lysine
- L-Ornithine, D-Ornithine
- L-Arginine
L-lysine is singled out in claims 7, 12, 18, 21+
- Claim 7: amino acid is L-Lysine.
- Claims 12 and 18: composition includes L-lysine and define longer stability windows.
- Dependent claims 21 and 23 add formulation specifics (PEG/solvent; ratio limits).
Design-around logic
- If the competitor can avoid inclusion of any amino acid that appears in the enumerated list, then dependent claims requiring a covered amino acid would not be met.
- However, claim 1 remains a risk if it is satisfied by pH-only (claim 2 dependents avoid this) or if the competitor uses any enumerated amino acid.
How do the vancomycin concentration and molar ratio limits constrain claim coverage
Vancomycin concentration gate
Across claims:
- vancomycin is about 0.5–5% w/V.
This means compositions below 0.5% or above 5% fall outside the literal claim language. “About” adds flexibility but does not eliminate the need to remain close to that range for enforcement.
Ratio gates
N-acetyl-D-alanine : vancomycin
- Claim 3: ~1:1 to 30:1
- Claims 15 and 22: same ratio range in the lysine composition family
L-amino acid : vancomycin
- Claim 10: ~1:1 to 20:1 where the amino acid is present under claim 5
This creates an infringement and validity dynamic: competitors cannot rely only on “achieving similar stability”; they must land within the defined stoichiometry if the asserted claims include those ratio limitations.
Does the patent lock the analytical method, and how does USP 36-NF 31 LC testing matter
Several dependents require measurement of vancomycin remaining by liquid chromatography in accordance with USP 36-NF 31 (claims 4, 11, 17, 24).
This limitation can matter in two ways:
- Literal infringement: to assert those dependents, the observed stability data must be obtained via that specified LC/compendial method.
- Litigation proof: if a competitor uses a different analytical protocol, the patentee may need to show equivalence or how the competing method still maps to “in accordance with” USP compendial guidance under the claim’s construction.
The broader independent claim 1 does not explicitly require the LC limitation, but the stability quantification (≥90% at 10 weeks) will still be anchored to measured potency in practice.
What specific formulations are claimed with PEG and organic solvent
A singled-out example adds an organic solvent component:
- Claim 14: includes ~0.5% w/V vancomycin and a pharmaceutically acceptable organic solvent comprising ~1.8% V/V polyethylene glycol
- Claim 21: mirrors this structure inside the lysine family
Scope impact
- The PEG/organic solvent limitation is narrower than the general aqueous composition claims.
- It can function as:
- an additional infringement hook for a particular commercial formulation; and
- a design-around lever for competitors that achieve stability using different excipient systems.
How strong is the patent estate around these claims (within the provided claim set)
Based strictly on the claim language provided (and not on the wider family), the estate appears to have:
- Broad coverage through claim 1’s structure (aqueous, vancomycin 0.5–5% w/V, N-acetyl-D-alanine, stable ≥10 weeks at 25°C with ≥90% remaining; pH 4.5–5.5 and/or amino acid).
- Layered dependent claims tightening:
- pH window,
- amino acid selection and particularly L-lysine,
- stoichiometry,
- compendial LC testing,
- and an example formulation with PEG (~1.8% V/V).
This multi-layer drafting is typical of patents intended to preserve infringement options against slightly modified competitors.
Where would generic or alternative formulations face highest infringement risk
Risk is highest when a candidate product matches a set of features simultaneously:
- Dose form: stable aqueous solution meeting 0.5–5% w/V vancomycin
- Stabilizer system: contains N-acetyl-D-alanine
- Stability: demonstrates ≥90% vancomycin remaining at 10 weeks (25°C) and/or meets the longer-window endpoints in the lysine claims
- pH and/or amino acid:
- pH 4.5–5.5, and/or
- inclusion of an enumerated amino acid (especially L-lysine)
- Stoichiometry:
- N-acetyl-D-alanine : vancomycin within 1:1 to 30:1
- amino acid : vancomycin within 1:1 to 20:1 where applicable
- Excipient system: if using PEG near 1.8% V/V, claim 14/21 risk increases
Claim-by-claim scope map of US 10,849,956 (provided claims only)
| Claim |
Core limitations (high signal) |
Main effect on scope |
| 1 |
Aqueous stable composition: vancomycin 0.5–5% w/V + N-acetyl-D-alanine; stable ≥10 weeks at ~25°C with ≥90% remaining; pH 4.5–5.5 and/or amino acid |
Broad independent; multiple infringement paths (pH-based or amino-acid-based) |
| 2 |
Claim 1 + pH 4.5–5.5 |
Narrower certainty for pH-based products |
| 3 |
Claim 1 + N-acetyl-D-alanine:vancomycin 1:1–30:1 |
Stoichiometry constraint |
| 4 |
Claim 1 + stability assay by LC per USP 36-NF 31 |
Analytical-method-limited dependent |
| 5 |
Claim 1 + composition comprises an amino acid |
Amino-acid required |
| 6 |
Claim 5 + amino acid is one of listed D/L amino acids |
Enumerated amino acid scope |
| 7 |
Claim 5 + amino acid is L-lysine |
Narrowest amino-acid dependent |
| 8 |
Claim 5 + pH 4.5–5.5 |
pH-limited amino acid family |
| 9 |
Claim 5 + N-acetyl-D-alanine:vancomycin 1:1–30:1 |
Stoichiometry within amino-acid dependent branch |
| 10 |
Claim 5 + amino acid:vancomycin 1:1–20:1 |
Stoichiometry within amino-acid dependent branch |
| 11 |
Claim 5 + assay by LC per USP 36-NF 31 |
Analytical-method-limited dependent |
| 12 |
Vancomycin 0.5–5% w/V + N-acetyl-D-alanine + L-lysine; stable ≥3 months at 25°C with ≥85% at 3 months OR ≥12 months with ≥85% at 12 months |
Product-like lysine embodiment |
| 13 |
Claim 12 + pH 4.5–5.5 |
pH-limited lysine embodiment |
| 14 |
Claim 12 + vancomycin ~0.5% w/V + solvent includes ~1.8% V/V PEG |
Excipient-specific embodiment |
| 15 |
Claim 12 + N-acetyl-D-alanine:vancomycin 1:1–30:1 |
Ratio-limited lysine embodiment |
| 16 |
Claim 12 + L-lysine:vancomycin 1:1–20:1 |
Ratio-limited lysine embodiment |
| 17 |
Claim 12 + assay by LC per USP 36-NF 31 |
Analytical-method-limited lysine dependent |
| 18 |
Variant of claim 12 where at least 3 months ≥90% at 3 months? (as written) and/or 12 months ≥85%; stable for 3 months and 12 months at 25°C with defined endpoints |
Independent in provided set; includes stability variants |
| 19 |
Claim 18 + at 12 months vancomycin remaining ≥90% |
Tightens long-term endpoint |
| 20 |
Claim 18 + pH 4.5–5.5 |
pH-limited |
| 21 |
Claim 18 + vancomycin ~0.5% w/V + ~1.8% V/V PEG |
PEG-specific |
| 22 |
Claim 18 + N-acetyl-D-alanine:vancomycin 1:1–30:1 |
Ratio-limited |
| 23 |
Claim 18 + L-lysine:vancomycin 1:1–20:1 |
Ratio-limited lysine embodiment |
| 24 |
Claim 18 + assay by LC per USP 36-NF 31 |
Analytical-method-limited |
Key takeaways
- US 10,849,956 claims stable aqueous vancomycin achieved by N-acetyl-D-alanine plus pH 4.5–5.5 and/or an amino acid, with quantified stability endpoints at 25°C.
- The enforceable scope is constrained by:
- vancomycin concentration 0.5–5% w/V,
- stability thresholds (≥90% at 10 weeks and longer-window ≥85%/≥90% endpoints),
- optional but critical formula gates (pH range, amino acid presence, amino acid identity, molar ratios),
- and in several dependents, LC assay per USP 36-NF 31.
- The lysine sub-family (claims 12/18/19 and related dependents) is the most specific pathway: it targets L-lysine formulations and tightens stability and ratio limits and, in one dependent, a PEG (~1.8% V/V) excipient example.
FAQs
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What formulation elements are mandatory to infringe claim 1 of US 10,849,956?
vancomycin 0.5–5% w/V, N-acetyl-D-alanine, aqueous composition stable ≥10 weeks at ~25°C with ≥90% remaining, plus pH 4.5–5.5 and/or an amino acid.
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Can a competitor avoid infringement by changing pH outside 4.5–5.5?
Potentially, if the formulation still avoids meeting the “pH 4.5–5.5 and/or amino acid” logic used by claim 1 and the dependent claims that require that pH range, while also failing stability thresholds.
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Which amino acids are explicitly covered with L-lysine being the most directly targeted?
The claim list includes D-alanine, D-serine, D-leucine, D-valine, L-lysine, D-lysine, L-ornithine, D-ornithine, and L-arginine, with multiple claims emphasizing L-lysine.
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Does the patent require USP 36-NF 31 liquid chromatography for measuring vancomycin remaining?
Only for the dependent claims that incorporate that limitation (e.g., claims 4, 11, 17, 24).
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How do molar ratio limits affect design-around strategies?
They create literal gates: N-acetyl-D-alanine:vancomycin 1:1–30:1 and amino acid:vancomycin 1:1–20:1 (in the relevant dependents), meaning stability alone is not sufficient if a formulation sits outside those ratios.
References (APA)
- United States Patent 10,849,956. (provided claim text).
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