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Patent landscape, scope, and claims: |
Scope of US Patent 7,572,789 (KATP channel opener salt + oral sustained/enteric formulations) and the US patent landscape around it
US 7,572,789 is directed to (i) salts of a KATP channel opener defined by structural “Formula III” and “Formula IV” plus specific counterions, and (ii) pharmaceutical formulations that include those salts, with explicit coverage for oral, enteric-coated, and sustained-release dosage forms and release profiles. In the US, the claims are structured to be infringement-relevant for both the active substance (salt form) and finished dosage forms (formulation and release engineering), with diazoxide and particular counterions called out in dependent claims.
What patents protect KATP channel opener salts like diazoxide in US 7,572,789?
What is the claimed “active” scope in Claim 1 (salt of Formula III/IV KATP opener)?
Claim 1 is the foundational compound claim. It recites:
Practical infringement consequence: Claim 1 is not limited to diazoxide alone. It is written to cover a class of KATP channel opener structures defined by Formula III/IV plus a specific counterion selection, but the R-substitution is narrowed by the “no amino group on substituted lower alkyl” restrictions.
How dependent claims narrow Claim 1 to diazoxide and specific counterions?
The patent narrows the class to known actives and counterions:
- Claim 2: KATP channel opener is diazoxide.
- Claim 3: diazoxide + counterion choline.
- Claim 4: diazoxide + counterion hexamethyl hexamethylene diammonium.
Practical consequence: For diazoxide, the counterion becomes the primary differentiator. A competitor using diazoxide in another salt form may avoid Claims 3 and 4 but could still face exposure under Claim 2 (if the salt falls within Claim 1’s counterion set as construed from the “as shown below” counterion table).
Does Claim 1 cover multiple salt forms or only the explicitly listed counterions?
Claim 1 states: “a counter ion as shown below.” That means the scope is limited to the counterion options enumerated in the claim’s “counter ion as shown below” portion. Without the “below” counterion definitions, the counterion universe cannot be enumerated here, but the dependent claims clearly include at least choline and hexamethyl hexamethylene diammonium.
Which formulation claims does US 7,572,789 cover: oral, enteric-coated, and sustained release?
What does Claim 5 cover (salt-containing formulations)?
- Claim 5: A pharmaceutical formulation comprising:
- the salt of Claim 1, plus
- at least one pharmaceutically acceptable excipient.
This is a broad formulation claim. It can cover excipient-containing tablets, capsules, pellets, granules, and multipart dosage forms, provided they contain the claimed salt.
What does Claim 6 add (oral dosage forms)?
- Claim 6: The formulation is an oral dosage form.
This restricts the dosage route to oral administration but still leaves high flexibility in dosage form type.
How far does enteric coating coverage go (Claims 7-8)?
- Claim 7: formulation is an enteric coated formulation.
- Claim 8: enteric coating is one of:
- (a) compression coating on a tablet
- (b) thin film on a tablet
- (c) coating on microparticles, where microparticles can be further encapsulated.
Practical consequence: If an accused product uses the claimed salt in an enteric-coated architecture of any of these three types, it is squarely within Claims 7 and 8. That is formulation architecture coverage, not merely general “enteric coating.”
What does sustained release coverage look like (Claims 9-11)?
- Claim 9: formulation is a sustained release formulation.
- Claim 10: release period 8–24 hours after administration.
- Claim 11: sustained release formulation comprises at least one component selected from a long list:
- (a) pH sensitive polymeric coating
- (b) hydrogel
- (c) film coating controlling diffusion rate of salt from coated matrix
- (d) non-erodable matrix controlling rate of salt release
- (e) polymer coated pellets/granules/microparticles of salt, optionally further encapsulated or compressed into a tablet
- (f) osmotic pump system containing the salt
- (g) compression coated tablet form of the salt
- (h) combinations thereof
Practical consequence: Claim 11 is designed to cover multiple sustained-release engineering strategies. A generic or reformulation competitor that changes the delivery system must still avoid both the claimed salt and the covered sustained-release architecture selections if those are interpreted as “comprises a component selected from” (which typically means including at least one of the listed component types).
What are the dosage amount windows (Claims 12-13)?
- Claim 12: single administration contains 10 to 2000 mg of the salt.
- Claim 13: single administration contains 300 to 500 mg of the salt.
Practical consequence: These ranges matter for infringement of formulation products, especially if competitors attempt to change dose strengths. However, Claim 12 covers a wide span that will capture many diazoxide regimens unless dosing is deliberately outside the claimed salt amount.
What is the second release window (Claim 14)?
- Claim 14: sustained release period 2–30 hours.
Claim 10 vs Claim 14: Claim 10 is narrower (8–24 hours) while Claim 14 covers an expanded window (2–30). A product with a release profile within 8–24 h likely satisfies both, depending on how the court construes measurement and whether “period of release” is a functional parameter tied to dissolution testing conditions.
How strong is the claim set: where are the likely infringement hotspots and where are design-arounds available?
Hotspots for infringement
- Salt identity: A product’s API salt form is central, especially for dependent claims specifying counterions.
- Enteric-coated architecture: Claims 7-8 are specific about coating implementation modes.
- Sustained release strategy: Claim 11 is broad across multiple release mechanisms.
- Dose strength windows: Claims 12-14 create numeric hooks for dosage form strengths and release timing.
Design-around pressure points
- Counterion substitution: Using diazoxide with a counterion not within the “counter ion as shown below” set may avoid dependent Claims 3 and 4 and potentially the broader salt claim scope depending on construction.
- Avoiding both enteric and sustained release combinations: If a competitor makes an immediate-release form, it can avoid Claims 7-11, but it still faces Claim 5-6 (salt in oral formulation). If it uses a different salt, it can avoid Claims 1-4 and therefore the downstream formulation claims.
- Changing component strategy: Because Claim 11 uses a “selected from” list and “comprises” language, a competitor must avoid the inclusion of at least one of the claimed component types to exit the claim’s scope, depending on claim construction.
How does US 7,572,789 compare with typical KATP-diazoxide patent estates (salt vs formulation vs method)?
US 7,572,789 is a salt + formulation estate, not a method-of-treatment claim set in the text provided. That matters for competitive risk:
- Salt/formulation patents create barriers for:
- oral generics that rely on the same active but different salt forms,
- and line extensions that modify release behavior while keeping the same salt.
- If competitors rely on a different salt form and an alternate release system (non-overlapping with Claim 11 component types), they can reduce infringement risk.
What is the US Orange Book status and generic entry risk for products using diazoxide salts covered by 7,572,789?
The requested analysis requires the patent’s Orange Book listing(s) (drug product, NDA/ANDA, listed use codes, and whether 7,572,789 is listed to protect the approved formulation). That information is not present in the prompt. Without Orange Book data, a claim-to-regulatory-risk map cannot be built.
Same constraint applies to Paragraph IV filing risk, FDA match codes, and timing for exclusivity/expiration for specific product approvals.
What litigation events or settlements involve US 7,572,789?
The prompt provides claim text only and no case captions, docket numbers, litigated patents, or jurisdictions. Without that, a litigation-status section would be incomplete.
Key Takeaways
- US 7,572,789 protects KATP channel opener salts defined by Formula III/IV with specific R-substitution constraints and a counterion set defined in the claim’s “as shown below” portion.
- Dependent claims directly target diazoxide salts with specific counterions including choline and hexamethyl hexamethylene diammonium.
- The formulation estate is built for oral dosage forms, with strong coverage for:
- enteric-coated tablets/microparticle architectures, and
- sustained release using multiple mechanism classes (pH-sensitive coatings, hydrogels, diffusion control films, non-erodable matrices, coated pellets, osmotic pump systems, compression-coated tablets).
- Numeric claim hooks exist for single dose salt amounts (10–2000 mg; 300–500 mg) and release windows (8–24 hours; also 2–30 hours), which can narrow or expand practical infringement for product-specific release and strength profiles.
FAQs
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Do Claims 3 and 4 require diazoxide specifically, or can other KATP openers qualify?
Yes, Claims 3 and 4 require diazoxide by their dependent claim language.
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If a product uses diazoxide but a different salt counterion, does it avoid all claims of US 7,572,789?
It may avoid the specific dependent claims (choline; hexamethyl hexamethylene diammonium), but exposure could remain under Claim 1 depending on whether the alternative counterion falls within the “counter ion as shown below” definitions.
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Can a competitor avoid the enteric-coated claims by using a different enteric coating form?
Claims 7-8 are tied to three coating implementations (compression-coated tablet, thin-film tablet, microparticles). Using a form outside those categories may reduce risk, but the salt-containing oral formulation claims still remain.
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Does Claim 11 require osmotic pumping to infringe, or is it enough to include any listed sustained-release component?
Claim 11 uses “comprises a component selected from” a list, so including at least one listed component type is sufficient if the claim is construed that way.
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How do the 8–24 hour and 2–30 hour release ranges affect infringement analysis?
A product with release characteristics within 8–24 hours likely falls within both Claim 10 and Claim 14 ranges; a product outside 8–24 but within 2–30 may still meet Claim 14.
References (APA)
- US Patent 7,572,789.
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