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Patent landscape, scope, and claims: |
United States Patent 7,598,343 (Bivalirudin compounding process): scope, claim-by-claim boundaries, and US patent estate risks
Executive summary
- US 7,598,343 is a formulation/process-chemistry patent covering compounded or prepared pharmaceutical batches of bivalirudin (SEQ ID NO: 1) for anticoagulant use, with the key limitations tied to:
- a specific pH adjustment window (about pH 5–6 when reconstituted),
- base identity (at least claims specify sodium hydroxide),
- a reconstitution-time bound (claim set includes ≤42 seconds, with narrower dependent limits),
- impurity control quantified by HPLC (Asp9-bivalirudin thresholds; total impurity thresholds), and
- carrier composition options (bulking/stabilizing agents, with a preferred embodiment as mannitol).
- In infringement and non-infringement analysis, the claim stack makes the patent easier to design around than broad “any bivalirudin formulation” coverage, because multiple independent claim elements are numerically constrained (impurity percentages, reconstitution time, pH).
- The highest litigation leverage typically comes from whether a competitor’s process can be shown (or ruled out) for (i) the pH-adjustment method, (ii) the reconstitution time, and (iii) impurity profile after preparation.
What is US Patent 7,598,343 and what does it cover for bivalirudin compounding?
Quick answer: US 7,598,343 claims pharmaceutical batches of bivalirudin made by a defined dissolve-pH-adjust-dry/solvent removal compounding process, with reconstituted pH ~5–6 and HPLC impurity limits, and in some claims a fast reconstitution time ceiling, plus optional mannitol/carrier and sodium hydroxide base constraints.
Claim “core” elements that define the patent’s scope
Across the independent claim group, the structure is consistent:
- Product substance: bivalirudin with the sequence explicitly defined as SEQ ID NO: 1.
- Intended use: anticoagulant for a subject in need.
- Batch/process steps:
- (i) dissolving bivalirudin in a solvent to form a first solution
- (ii) mixing with a pH-adjusting solution to form a second solution, where the pH-adjusting solution has a pH-adjusting solution solvent
- (iii) removing the solvent and pH-adjusting solution solvent from the second solution
- Critical formulation parameters:
- pH about 5–6 when reconstituted in an aqueous solution for injection
- impurity limits by HPLC, including Asp9-bivalirudin and total impurities
- Special process/performance limits in the second independent claim set:
- maximum reconstitution time ≤ about 42 seconds, with dependent narrowing
Why “batches” and “compounding process” matter
The claims are written as product-by-process / batch definition, which means a competitor can sometimes avoid infringement by changing:
- the pH adjustment chemistry (while still producing a reconstituted pH in the same range), or
- the order/solvent workup mechanics, or
- the impurity profile, or
- the reconstitution time, if that feature is in the asserted claim.
What are the exact claim limitations in US 7,598,343, element by element?
Below is a claim scope map based strictly on the claim text provided.
Claim 1 (independent): bivalirudin batches with Asp9 control and pH 5–6
Required limitations
- Pharmaceutical batches containing:
- bivalirudin (SEQ ID NO: 1)
- pharmaceutically acceptable carrier
- Use: anticoagulant
- Compounding process:
- dissolve bivalirudin in a solvent (first solution)
- efficiently mix with a pH-adjusting solution (second solution)
- pH-adjusting solution includes its own solvent
- remove both the solvent and pH-adjusting solution solvent
- Reconstituted pH: about 5–6 in aqueous solution for injection
- Asp9-bivalirudin impurity cap: ≤ about 0.6% by HPLC
Scope boundary
- Claim 1 is broad as to carrier type (only “pharmaceutically acceptable carrier”).
- It is narrow on the impurity cutoff (Asp9 ≤0.6%).
- It is process-constrained through the pH-adjusting solution mixing and solvent removal sequence.
Claim 2–3 (dependent): tighten Asp9-bivalirudin
- Claim 2: Asp9-bivalirudin ≤0.4% by HPLC
- Claim 3: Asp9-bivalirudin ≤0.3% by HPLC
Scope boundary
- These dependents create a graded envelope.
- If a competitor exceeds 0.6% Asp9, it does not meet claim 1.
- If it is ≤0.6% but >0.4%, it may meet claim 1 but avoid claim 2 and 3.
Claim 4–6 (dependent): total impurity caps
- Claim 4: total impurity ≤ about 2% by HPLC
- Claim 5: total impurity ≤ about 1%
- Claim 6: total impurity ≤ about 0.5%
Scope boundary
- These dependents also require Claim 1’s process/pH/acceptability and Asp9 cap from Claim 1 only (unless the dependent modifies it; the text here does not restate Asp9, so Claim 1’s Asp9 limit remains in effect for claims 4–6).
Claim 7 (dependent): D-Phe12-bivalirudin cap
- D-Phe12-bivalirudin ≤ about 2.5% by HPLC
Scope boundary
- This is an additional impurity constraint that can be used in infringement defense if the competitor’s profile is higher.
Claim 8–11 (dependent): carrier includes stabilizing/bulking; sugar (mannitol)
- Claim 8: carrier comprises bulking agent and/or stabilizing agent
- Claim 9: bulking agent is a sugar
- Claim 10: sugar is mannitol
- Claim 11: base is sodium hydroxide
Scope boundary
- Claims 9–10 are narrower embodiments within the broader “carrier/bulking” field.
- Claim 11 adds a base specificity, which matters if infringement is argued for claims that include the sodium hydroxide feature.
Claim 12 (independent): adds reconstitution time ceiling
This is a second independent claim with overlapping process and pH limits plus new performance and impurity features.
Required limitations
- Same core product and compounding process steps as Claim 1
- pH about 5–6 on reconstitution in aqueous solution for injection
- Maximum reconstitution time ≤ about 42 seconds
- Maximum total impurity level ≤ about 2% by HPLC
Claim 13–14 (dependent): tighten reconstitution time
- Claim 13: reconstitution time ≤ about 30 seconds
- Claim 14: reconstitution time ≤ about 21 seconds
Scope boundary
- Reconstitution time becomes a high-value design-around and evidentiary point because it is a numeric parameter that can be measured and compared.
Claim 15–18 (dependent): carrier and base = sodium hydroxide
- Claim 15: carrier comprises bulking and/or stabilizing agent
- Claim 16: bulking agent is sugar
- Claim 17: sugar is mannitol
- Claim 18: base is sodium hydroxide
Claim 19 (independent): mannitol + sodium hydroxide + reconstitution time + total impurity
Claim 19 is an independent claim that hard-codes carrier and base.
Required limitations
- Batches with:
- bivalirudin (SEQ ID NO: 1)
- mannitol as carrier component (via claim language)
- Compounding process: dissolve, mix with pH-adjusting solution, remove solvents
- Base: sodium hydroxide
- pH about 5–6 upon reconstitution
- Reconstitution time ≤ about 42 seconds
- Total impurity ≤ about 2% by HPLC
Claim 20 (dependent): tight Asp9 cap
- Claim 20 adds:
- Asp9-bivalirudin ≤ about 0.6% by HPLC
- (Within the Claim 19 framework)
Which parts of the claim set are broad vs easy to design around?
Broadest elements (harder to design around)
- “Pharmaceutically acceptable carrier” in Claim 1 (unless asserted claims require mannitol)
- General process framework: dissolve → pH-adjust → remove solvents (if a competitor uses the same platform, this element can be harder to change)
- Target pH window: about 5–6 on reconstitution
Most design-around-prone elements (strong boundaries)
- Asp9-bivalirudin impurity threshold:
- Claim 1: ≤0.6%
- Claim 2: ≤0.4%
- Claim 3: ≤0.3%
- Total impurity thresholds:
- Claim 4: ≤2%
- Claim 5: ≤1%
- Claim 6: ≤0.5%
- Claim 12/19: total impurity ≤2%
- Reconstitution time ceilings:
- Claim 12/19: ≤42 seconds
- Claim 13: ≤30 seconds
- Claim 14: ≤21 seconds
- Mannitol carrier specificity (Claims 10, 17, 19)
- Sodium hydroxide base specificity (Claims 11, 18, 19)
What patents protect bivalirudin formulation and compounding in the US near the same claim space?
Quick answer: Based on the claim content provided, US 7,598,343 targets a distinct subspace: pH-adjusted, solvent-worked bivalirudin batches with HPLC impurity control and reconstitution-time constraints. A competitor’s freedom-to-operate depends on whether other patents cover:
- the same impurity targets (Asp9-bivalirudin, D-Phe12-bivalirudin),
- the same reconstitution-time performance,
- or alternative pH adjustment/base/carrier schemes.
Scope implication for patent landscape diligence
For a practical landscape search and clearance, the relevant claim clusters to map are:
- bivalirudin bulk/pH adjustment methods (base identity, target pH on reconstitution)
- lyophilized or reconstitution-optimized presentations (reconstitution time)
- impurity reduction processes (Asp9-bivalirudin, total impurities, D-Phe12-bivalirudin)
- excipient selection (mannitol vs alternatives) and solvent removal/workup
(No additional patent numbers can be identified from the information supplied, so this analysis is limited to US 7,598,343’s scope and claim boundaries.)
When does US 7,598,343 lose exclusivity and what does term mean for a generic risk timeline?
Quick answer: Determining when US 7,598,343 loses exclusivity requires the patent’s legal status, filing and priority dates, and any terminal disclaimers and PTA. Those data are not included in the provided input, so a defensible launch-risk timeline cannot be produced here.
How strong is the patent estate for infringement risk on compounding and impurity specs?
Quick answer: Strength is driven by objective, testable constraints:
- if a competitor’s product after reconstitution yields pH outside 5–6, it avoids a core limitation
- if it produces Asp9-bivalirudin above the asserted cap, it avoids that claim
- if it exceeds total impurity limits, it avoids claim 4–6 and claim 12/19
- if reconstitution time exceeds the claimed ceiling, it avoids claim 12/13/14/19
Where infringement arguments typically concentrate
- Analytical testing alignment: Asp9-bivalirudin and total impurity are explicitly measured “as measured by HPLC,” making lab comparability central.
- Process-to-spec mapping: although the claims are process-defined, the litigation often centers on whether the resulting batch meets the impurity and reconstitution performance limitations.
- Measurement method disputes: “reconstitution time” and HPLC impurity quantitation depend on the testing protocol. If protocols differ, evidentiary fights may follow.
What generic entry risks exist for a bivalirudin anticoagulant product in the US under this patent?
Quick answer: The generic (or follow-on) risk under US 7,598,343 is highest if the applicant uses a process and formulation approach that lands inside:
- reconstitution pH 5–6
- impurity profile below:
- Asp9 ≤0.6% (and potentially lower)
- total impurities ≤2% (and potentially lower)
- reconstitution time ≤42 seconds (and potentially tighter)
Design-around scenarios created by the claim structure
- Switch carrier away from mannitol can avoid mannitol-dependent claims, but may not avoid Claim 1/12 unless asserted.
- Change base away from sodium hydroxide can avoid base-specific dependent claims (11/18/19), but again depends on which claim(s) are asserted.
- Increase residual Asp9 or total impurities beyond the capped thresholds can avoid specific dependent and even independent limitations if it moves above 0.6% Asp9 or 2% total impurities.
- Slow reconstitution above the time ceiling can avoid Claim 12/13/14/19.
How does US 7,598,343 compare with typical bivalirudin patent themes (impurities vs excipients vs methods)?
Quick answer: US 7,598,343 is more spec-driven than purely excipient- or purely method-of-synthesis-driven. It combines:
- impurity management (Asp9-bivalirudin; total impurity; D-Phe12-bivalirudin),
- reconstitution performance (time),
- and a pH adjustment workflow with defined solvents removal steps.
That hybrid nature often makes it harder to argue that an alternative formulation is “functionally equivalent” if it fails one numeric bound.
Which claims are most likely to be asserted in litigation and why?
Quick answer: Likely assertable claim set depends on product match, but from the text provided:
- Claim 1 is the broadest independent claim, capturing pH 5–6 and Asp9 ≤0.6%.
- Claim 12 becomes a second litigation anchor if the product has measurable reconstitution time ≤42 seconds and total impurities ≤2%.
- Claim 19 is a strong, narrow independent claim if the competitor’s formulation uses mannitol and sodium hydroxide base and meets the reconstitution/performance and impurity limits.
Key takeaways
- US 7,598,343 defines a bivalirudin batch compounding process that yields reconstituted pH about 5–6, with HPLC impurity caps that are numerically tight (notably Asp9-bivalirudin ≤0.6% in Claim 1).
- The claim set includes performance constraints through maximum reconstitution time ≤42 seconds (and dependent limits to 30 and 21 seconds), making it a measurable design-around lever.
- Mannitol and sodium hydroxide are not required for the broadest independent claim (Claim 1), but they are hard-coded in narrower independent Claim 19 and dependent claims.
- Clearance and litigation risk analysis should focus on objective testing outcomes: reconstituted pH, reconstitution time under the claimed protocol, and HPLC impurity quantitation (Asp9, D-Phe12, and total impurity).
FAQs
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Does US 7,598,343 require lyophilization or a specific dosage form?
The provided claim text defines “batches” and reconstitution into aqueous solution for injection, but it does not explicitly state lyophilization or a specific dosage form in the claim language provided.
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Can a product meet the pH 5–6 requirement but avoid infringement by exceeding the Asp9-bivalirudin limit?
Yes, if the applicable asserted claim requires Asp9-bivalirudin to be at or below the stated HPLC percentages and the product exceeds those thresholds.
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Is mannitol required to infringe US 7,598,343?
No. Mannitol is required only for the mannitol-specific dependent claims and the mannitol-based independent claim (Claim 19), not for Claim 1 as provided.
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What is the strongest single measurable parameter to test for claim 12/13/14/19 coverage?
Reconstitution time against the stated ceiling (42, 30, or 21 seconds) under the relevant testing protocol.
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If a competitor uses sodium hydroxide as the base, does that automatically create infringement risk?
Not automatically. Infringement still requires meeting the remaining elements, including the pH window, solvent-workup process steps, and the impurity and (where applicable) reconstitution-time limitations.
References
No sources were cited because no external documents (USPTO record, Orange Book, litigation docket, or related patents) were provided in the input.
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