Scope and Claims Dissection of U.S. Patent 9,919,026 (Vasopressin IV Composition, Impurity Profile, and HPLC/UV Quantitation) and the US Patent Landscape

U.S. Patent 9,919,026 claims a narrow intravenous vasopressin product definition tied to (i) a specific concentration range (0.1 to 2 µg/mL), (ii) a defined excipient system (about 5% dextrose and about 1 to 10 mM acetate buffer), (iii) a tight pH window (3.6 to 3.9, including specific sub-ranges), (iv) an impurity specification defined by peptide sequence homology to SEQ ID NO: 1 (85% to 100%) and quantitative impurity levels (0.9% to 1.7%), and (v) impurity identification/quantitation using a particular HPLC method with UV detection and peak integration. The claim set also includes optional variants distinguishing whether the dose contains vasopressin itself versus a pharmaceutically acceptable salt, plus dependent claims that lock in particular impurity peptides by SEQ ID numbers and their percentage ranges.

What does US Patent 9,919,026 claim for intravenous vasopressin drug product scope?

Core claim coverage (Claim 1): A pharmaceutical composition for IV administration in a unit dosage form comprising:

Vasopressin or pharmaceutically acceptable salt: 0.1 µg/mL to 2 µg/mL
Impurities: 0.9% to 1.7%, where impurities have 85% to 100% sequence homology to SEQ ID NO: 1
Dextrose: about 5%
Acetate buffer: 1 mM to 10 mM
pH: 3.6 to 3.9
Suitability: unit dosage form suitable for administration at concentrations matching the vasopressin range

Practical meaning for design-around: Any generic or biosimilar-style entry is forced into a highly constrained formulation space and, critically, into a matching impurity profile as defined by sequence homology to a reference peptide set plus quantitative impurity percentages. Even if a competitor matches concentration, excipients, and pH, it still risks non-infringement if its impurity profile does not meet the “0.9% to 1.7%” band or the “85% to 100% homology to SEQ ID NO: 1” criterion.

Which parts of Claim 1 are most likely to be infringement “tripwires”?

Impurity homology and impurity percentage bands
- “Impurities present in an amount of 0.9% to 1.7%” plus “85% to 100% sequence homology to SEQ ID NO: 1” creates a two-dimensional matching requirement.
- If a competitor’s impurity peptides are similar but below the homology threshold, or if their impurity load falls outside the quantitative range, it can argue non-infringement.
Tight pH and buffer strength
- pH 3.6 to 3.9 with acetate buffer 1 to 10 mM plus dextrose “about 5%.”
- Sub-ranges in dependent claims (see below) further narrow commercially relevant targets.
Defined IV unit dosage product concentration
- 0.1 to 2 µg/mL is narrow enough to exclude formulations outside that concentration envelope.

Does Claim 1 require a specific test method to prove impurity presence?

Claim 1 itself defines impurities structurally (homology) and quantitatively. It does not require the HPLC/UV procedure in Claim 2 to establish infringement. However, Claim 2 becomes highly relevant for enforcement because it operationalizes how to determine impurities.

How does dependent claim coverage narrow the impurity peptides (SEQ ID NO. variants) and concentration/pH sub-ranges?

Impurity peptides by SEQ IDs (Claims 3–9)

These claims move from “homology to SEQ ID NO: 1” to specific impurity identity anchors:

Claim 3: Impurities comprise SEQ ID NO: 2; SEQ ID NO: 2 present 0.1% to 0.3%
Claim 4: Impurities comprise SEQ ID NO: 3; SEQ ID NO: 3 present 0.1%
Claim 5: Impurities comprise SEQ ID NO: 4; SEQ ID NO: 4 present 0.2% to 0.4%
Claim 6: Impurities comprise SEQ ID NO: 7; SEQ ID NO: 7 present 0.3% to 0.6%
Claim 7: Impurities comprise SEQ ID NO: 10; SEQ ID NO: 10 present 0.1%
Claim 8: Impurities comprise SEQ ID NO: 2 and SEQ ID NO: 4; SEQ ID NO: 2 0.1% to 0.3% and SEQ ID NO: 4 0.2% to 0.4%
Claim 9: Further impurities comprise SEQ ID NO: 3, SEQ ID NO: 7, and SEQ ID NO: 10 with:
- SEQ ID NO: 3 at 0.1%
- SEQ ID NO: 7 at 0.3% to 0.6%
- SEQ ID NO: 10 at 0.1%

Strategic enforcement impact: A patentee can select the narrowest dependent claim matching the accused product’s impurity panel. In product-development or licensing negotiations, this gives a clear “allowed impurity makeup” target.

Salt versus non-salt (Claims 10–11)

Claim 10: Unit dosage form contains a pharmaceutically acceptable salt of vasopressin
Claim 11: Unit dosage form contains vasopressin salt is not present

Meaning: The patent is written to cover both salt and non-salt forms. That reduces a common design-around lever.

Specific pH windows (Claims 12–14)

Claim 12: pH 3.74 to 3.75
Claim 13: acetate buffer about 1 mM, and pH 3.7 to 3.9
Claim 14: acetate buffer about 10 mM, and pH 3.6 to 3.7

Meaning for formulation teams: These sub-claims define “product fingerprint” combinations: a low buffer level pairs with a high end of pH, while a higher buffer level pairs with a lower pH.

What is the infringement-proof method in Claim 2 for impurities (HPLC gradient + UV spectrum)?

Claim 2 adds a determinative method for impurities comprising a multi-step analytical process:

Sample prep: inject the unit dosage form into a high pressure liquid chromatography apparatus.
Column/adsorbent stationary phase: chromatography column with adsorbent particles stationary phase.
Mobile phases:
- First mobile phase: phosphate buffer at pH 3
- Second mobile phase: 50:50 acetonitrile:water
Run conditions: run through the column for 55 minutes
Elution: elute vasopressin and impurity peptides using a gradient of both mobile phases.
Flow rate: both first and second mobile phases run at 1 mL/min.
Detection: pass eluent through a UV detector to generate a UV spectrum
Identification: identify peptide of interest by retention time relative to a standard
Quantification: compute amount by integration of the peak from the UV spectrum

Enforcement leverage: Claim 2 can be used to argue that infringement is demonstrated through a particular validated analytical workflow. For litigation, this can reduce disputes over how “impurities” are measured and mapped to SEQ ID peptides.

Design-around note: A competitor could attempt to quantify impurities differently or use alternative chromatographic conditions; however, non-infringement depends on whether Claim 2 is a required element in the asserted claim (it is incorporated into Claim 2 only, not Claim 1).

What does this patent likely protect in a US product business sense (formulation and impurity “fingerprint”)?

Even without the listed patent description, the claim language indicates product protection at the level that matters for real-world commercialization:

Formulation space: IV vasopressin at a specific concentration with dextrose and acetate buffer and a narrow pH window.
Manufacturing-derived impurity profile: quantified impurity peptides by sequence homology and/or specific SEQ ID peptides with exact percentage bands.
Quality analytics: HPLC/UV method specifies identification by retention time to standards and quantification by UV peak integration.

This is closer to a “product and release-spec definition” than a purely active ingredient or general buffer-and-sugar composition claim.

When does US Patent 9,919,026 lose exclusivity (patent expiration timing)?

This analysis cannot compute a calendar expiration date without the patent’s filing date, nonprovisional priority date, and maintenance or PTA/PTE details. The user-supplied content includes claims but not bibliographic data. Under the operating constraints, no incomplete or speculative timeline is provided.

What are the likely Orange Book implications for Paragraph IV generic entry risk?

No Orange Book-listed drug name, NDC, or listed patents for the relevant vasopressin product are provided in the prompt. Without the FDA label mapping and Orange Book patent linkage, this cannot be tied to Paragraph IV filing windows or “listed patent” status.

How strong is the patent estate based on claim breadth and built-in measurement specificity?

Strength indicators from claim structure:

Claim 1 is broad in one dimension (impurities defined by homology to SEQ ID NO: 1 plus a quantitative band 0.9% to 1.7%) and covers salts and non-salts.
Claim 2 is enforcement-favorable because it defines an operational method for measuring impurity panels with retention-time identification and UV integration.
Claim 3–9 create multiple narrower claim paths that match specific impurity peptides at defined amounts. This creates “multiple landing zones” for infringement arguments depending on which impurity profile the accused product exhibits.
Dependent claims 12–14 lock in product-specific pH and buffer conditions, narrowing design-around freedom.

Weakness indicators:

The central vulnerability for challengers is that infringement is likely contingent on matching not only formulation conditions but also the impurity makeup. That makes it potentially easier to pursue non-infringement via impurity engineering and analytical divergence, but harder to fully avoid overlap if the same manufacturing route is used.

What generic entry risks exist for IV vasopressin if a competitor copies excipients and pH but not impurity profile?

If an accused product matches:

vasopressin concentration (0.1–2 µg/mL),
about 5% dextrose,
acetate buffer (1–10 mM),
pH (3.6–3.9),

it still must also meet the impurity constraint:

total impurities 0.9%–1.7% with impurity peptides in the required homology range to SEQ ID NO: 1.

If a generic manufactures using different stressors or purification profiles, impurity peptide identity and distribution may shift. In that case, the comparator can argue that it does not satisfy the “impurities have from 85% to 100% sequence homology to SEQ ID NO: 1” requirement or that the impurity amount is outside the claimed band.

Which competing vasopressin products and manufacturers are exposed to this patent?

No commercial product identifiers, assignees, or FDA labels are included in the prompt. Without the patent’s assignee and without linkage to NDCs or marketed brands, identifying exposed manufacturers cannot be done without guessing.

Key claim mapping table (what each claim element requires)

Claim	Required IV unit dosage formulation elements	Impurity definition	Test/method elements
1	Vasopressin or salt: 0.1–2 µg/mL; about 5% dextrose; acetate buffer 1–10 mM; pH 3.6–3.9; suitable for IV administration at that concentration	Impurities 0.9%–1.7%; impurities have 85%–100% sequence homology to SEQ ID NO: 1	Not required in Claim 1
2	Same as Claim 1	Impurities determined via HPLC method	HPLC + phosphate buffer pH 3 + acetonitrile:water 50:50 gradient; 55 min; UV detector; retention time vs standard; peak integration
3	Same as Claim 1	SEQ ID NO: 2 present 0.1%–0.3%	Not specified beyond Claim 2 if asserted together
4	Same as Claim 1	SEQ ID NO: 3 present 0.1%	-
5	Same as Claim 1	SEQ ID NO: 4 present 0.2%–0.4%	-
6	Same as Claim 1	SEQ ID NO: 7 present 0.3%–0.6%	-
7	Same as Claim 1	SEQ ID NO: 10 present 0.1%	-
8	Same as Claim 1	SEQ ID NO: 2 (0.1%–0.3%) + SEQ ID NO: 4 (0.2%–0.4%)	-
9	Same as Claim 1	SEQ ID NO: 2, SEQ ID NO: 4 plus SEQ ID NO: 3 at 0.1%, SEQ ID NO: 7 at 0.3%–0.6%, SEQ ID NO: 10 at 0.1%	-
10	Same as Claim 1	-	Adds salt-of-vasopressin present
11	Same as Claim 1	-	Adds salt-of-vasopressin not present
12	Adds pH range	-	-
13	Adds acetate buffer about 1 mM and pH 3.7–3.9	-	-
14	Adds acetate buffer about 10 mM and pH 3.6–3.7	-	-

What is the likely litigation posture given these claim elements?

Based on the claim set alone, the likely dispute axes are:

Analytical mapping: whether the accused impurity peptides correspond to the claimed SEQ ID-derived impurity constructs (homology threshold and peptide identity).
Quantitation: whether impurity load sits within 0.9%–1.7% and within dependent claim percentage bands (0.1%, 0.2–0.4%, 0.3–0.6%).
Formulation matching: whether pH and acetate buffer strength land inside 3.6–3.9 and the dependent sub-windows (3.74–3.75, 1 mM + pH 3.7–3.9, 10 mM + pH 3.6–3.7).

However, the prompt provides no docket history, asserted patents, parties, or settlements. Under the constraints, no specific litigation status is provided.

Key Takeaways

U.S. Patent 9,919,026 protects an IV vasopressin unit dosage composition defined by concentration (0.1–2 µg/mL), excipients (about 5% dextrose; acetate buffer 1–10 mM), and a tight pH window (3.6–3.9).
The most constraining element is the impurity profile: impurities at 0.9%–1.7% with peptides showing 85%–100% sequence homology to SEQ ID NO: 1, plus dependent claim coverage for specific SEQ ID impurity peptides at defined percentage bands.
Claim 2 adds an enforcement-friendly HPLC/UV determination workflow (phosphate buffer pH 3 and 50:50 acetonitrile:water gradient; 55 minutes; UV spectra; retention-time identification; peak integration).
The patent covers both salt and non-salt vasopressin formulations and includes tight pH/buffer sub-range dependent claims, reducing straightforward formulation-only design-around.

FAQs

1) Can a competitor avoid infringement by changing pH slightly outside 3.6–3.9?
The claim 1 pH requirement is 3.6–3.9, with dependent sub-ranges including 3.74–3.75. Moving outside those windows is a direct way to fail Claim 1’s formulation limitation.

2) If a generic matches excipients but has lower total impurity than 0.9%, does it still infringe?
Claim 1 requires impurities present at 0.9%–1.7%. A lower impurity amount avoids that quantitative limitation.

3) Is the HPLC method in Claim 2 required to establish infringement for Claim 1?
Claim 1 does not expressly require the method. The method is an additional limitation in Claim 2 when Claim 2 is asserted.

4) Do dependent claims force the presence of specific SEQ ID impurities?
Yes. Claims 3–9 specify which SEQ ID peptides are present and at what percentage ranges. Those dependent claims are infringed only if those impurity peptides are present within the stated amounts.

5) Does the patent distinguish salt forms in a way that can be designed around?
The patent includes both variants: salt present (Claim 10) and salt not present (Claim 11). Salt/non-salt does not appear to be an escape route from Claim 1.

References (APA)

U.S. Patent No. 9,919,026, claims 1–14.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Ph Health	VASOSTRICT	vasopressin	SOLUTION;INTRAVENOUS	204485-005	Apr 21, 2021	AP	RX	Yes	Yes	9,919,026	⤷ Start Trial	Y				⤷ Start Trial
Ph Health	VASOSTRICT	vasopressin	SOLUTION;INTRAVENOUS	204485-003	Apr 15, 2020	AP	RX	Yes	Yes	9,919,026	⤷ Start Trial	Y				⤷ Start Trial
Ph Health	VASOSTRICT	vasopressin	SOLUTION;INTRAVENOUS	204485-006	Apr 12, 2023		DISCN	Yes	No	9,919,026	⤷ Start Trial	Y				⤷ Start Trial
Ph Health	VASOSTRICT	vasopressin	SOLUTION;INTRAVENOUS	204485-004	Apr 15, 2020		DISCN	Yes	No	9,919,026	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Details for Patent: 9,919,026

Which drugs does patent 9,919,026 protect, and when does it expire?

Summary for Patent: 9,919,026