US Patent 9,675,549: Scope, Claim Structure, and Patent Landscape
United States Patent 9,675,549 is directed to tablet formulations of N-(5-tert-butyl-isoxazol-3-yl)-N′-{4-[7-(2-morpholin-4-yl-ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl}urea (and pharmaceutically acceptable salts) specifically in a composite with hydroxypropyl-β-cyclodextrin at defined weight ratios, combined with tight formulation constraints on excipients (lubricant, diluent, and hydroxypropyl cellulose). The claims are narrow in two ways: (1) they lock the API to a particular chemical identity (or salt) and (2) they lock the formulation to a specific composite ratio and excipient ranges, with additional dependency to process form (spray-dried or lyophilized) and coating status.
What exactly is claimed? (Claim-by-claim scope)
Claim 1: Core composition-of-tablet with composite + excipient system
Independent Claim 1 defines a tablet with all of the following:
-
Active ingredient identity
- API:
N-(5-tert-butyl-isoxazol-3-yl)-N′-{4-[7-(2-morpholin-4-yl-ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl}urea
or a pharmaceutically acceptable salt of that API.
-
Composite with hydroxypropyl-β-cyclodextrin at a defined weight ratio
- The API forms a composite with hydroxypropyl-β-cyclodextrin at 1:8 to 1:20 by weight.
-
Composite loading at a defined share of total tablet weight
- The tablet contains the composite at about 85 wt% or more of the total tablet weight.
-
Lubricant system (two alternative ingredient sets with ranges)
- Option A: calcium stearate or magnesium stearate, 0.5 to 1.5 wt%
- Option B: talc or sodium stearyl fumarate, 0.5 to 2.5 wt%
-
Diluent system (two alternatives with ranges)
- microcrystalline cellulose or D-mannitol, 3 to 10 wt%
-
Binder/structure component
- hydroxypropyl cellulose, 0 to 4 wt%
Scope meaning: To infringe Claim 1, a tablet must meet all constraints simultaneously: the specific API (or its salt), the composite ratio range (HPβCD), and the excipient ranges with the specified categories.
Claim 2: Narrowed example ranges within Claim 1
Claim 2 depends on Claim 1 and narrows parameters to a specific set of ranges:
- magnesium stearate: about 1 wt%
- diluent: microcrystalline cellulose or D-mannitol: about 4 to 7.5 wt%
- hydroxypropyl cellulose: about 0 to 4 wt%
Scope meaning: Claim 2 is not “broader”; it is a narrower embodiment. It is useful for validity and design-around analysis because it pins a practical formulation window.
Claim 3: Product-by-process (tablet obtainable by forming)
Claim 3 depends on Claim 1 and defines a tablet as one obtainable by forming a composition comprising the composite into a tablet.
Scope meaning: This is a low-impact limitation because “forming” is inherent to tablet manufacturing. It still matters in litigation because product-by-process language can become relevant if a party argues process distinguishes products, but the claim does not add a technical manufacturing parameter beyond “forming.”
Claim 4: Coated tablet
Claim 4 depends on Claim 1 and requires the tablet is coated.
Scope meaning: This expands the covered embodiments beyond uncoated tablets by explicitly including coated forms.
Claim 5: Film-coated tablet
Claim 5 depends on Claim 4 and specifies the coating is film coated.
Scope meaning: Narrower than Claim 4; covers a specific coating type.
Claim 6: Fixed composite ratio of 1:10
Claim 6 depends on Claim 1 and requires the composite of API (or salt) with hydroxypropyl-β-cyclodextrin at 1:10 by weight.
Scope meaning: Claim 6 is a concrete point within the broad 1:8 to 1:20 range of Claim 1. Practically, it matters because a competitor formulation may deliberately choose 1:9, 1:12, or 1:15, escaping Claim 6 while still being within Claim 1.
Claim 7: Composite is spray-dried powder
Claim 7 depends on Claim 1 and limits the composite to spray-dried powder.
Scope meaning: This ties to the solid-state manufacturing history of the composite, not just its composition. It provides a potential infringement hook if the accused product’s composite preparation matches spray drying.
Claim 8: Composite is lyophilized powder
Claim 8 depends on Claim 1 and limits the composite to lyophilized powder.
Scope meaning: Another solid-state manufacturing pathway. Like Claim 7, it can matter when proving product-by-process or solid-state identity.
Claim 9: Salt form specified
Claim 9 depends on Claim 1 and specifies the API as the dihydrochloride salt:
- N-(5-tert-butyl-isoxazol-3-yl)-N′-{4-[7-(2-morpholin-4-yl-ethoxy)imidazo[2,1-b][1,3]benzothiazol-2-yl]phenyl}urea dihydrochloride
Scope meaning: This is a salt-specific embodiment. If a competitor uses a different salt form (or free base), Claim 9 may not apply, but Claim 1 still could if the salt is “pharmaceutically acceptable” and the formulation meets all other limits.
Where is the legal “center of gravity”? (Main infringement drivers)
1) Composite ratio and composite loading
The strictest formulation locks are:
- HPβCD composite ratio: 1:8 to 1:20 by weight
- Composite weight share of tablet: about 85 wt% or more
These two factors likely drive the largest overlap with real commercial formulations because they define the majority of tablet mass. If a generic or follow-on product uses a different inclusion approach (lower composite loading, different carrier, or different complexation ratio), it risks falling outside Claim 1.
2) Excipients must land inside the enumerated categories and ranges
Claim 1 does not allow arbitrary excipient substitution. It forces:
- lubricant chosen from a listed set, within a listed wt% range
- diluent chosen from a listed set, within a listed wt% range
- hydroxypropyl cellulose within 0 to 4 wt%
This creates multiple design-around pathways, but each pathway must maintain the essential composite identity and loading constraints.
3) Solid form limitations are in dependent claims
Spray-dried vs lyophilized (Claims 7 and 8) and specific composite ratio 1:10 (Claim 6) sit in dependent claims. In a dispute, an accused product that meets Claim 1 could still infringe even if it avoids Claims 6-9, depending on coating status (Claims 4-5) and composite preparation method (Claims 7-8).
How broad is the scope? (Coverage mapping)
A. Parameter coverage grid
Below is a practical mapping of what is “open” vs “locked.”
| Parameter |
Claim 1 coverage |
Dependent claims that narrow |
| API identity |
specific API or pharmaceutically acceptable salt |
Claim 9 specifies dihydrochloride |
| HPβCD composite ratio |
1:8 to 1:20 |
Claim 6 sets 1:10 |
| Composite loading |
≥ about 85 wt% |
none further specified in dependents |
| Lubricant |
listed options with 0.5–1.5% (stearates) or 0.5–2.5% (talc/fumarate) |
Claim 2 selects magnesium stearate at ~1% |
| Diluent |
microcrystalline cellulose or D-mannitol 3–10% |
Claim 2 sets 4–7.5% |
| Hydroxypropyl cellulose |
0–4% |
Claim 2 keeps 0–4% |
| Coating |
covered only if coated (Claim 4/5) |
Claims 4-5 require coated/film coated |
| Composite manufacture form |
not specified in Claim 1 |
Claims 7-8 specify spray-dried vs lyophilized |
Implication: The most constraining features for most competitors are the composite ratio window and the very high composite loading (≥85 wt%).
What would fall outside the claims? (Design-around logic anchored to the text)
The following are straightforward noninfringement strategies based strictly on Claim 1’s structure:
-
Alter the HPβCD composite ratio outside 1:8 to 1:20
- Moving to ratios below 1:8 or above 1:20 avoids the composite-ratio requirement.
-
Reduce composite loading below about 85 wt%
- Claim 1 requires composite at about 85 wt% or more of tablet mass. Lowering composite fraction is a direct escape from Claim 1.
-
Use a lubricant/diluent outside the enumerated sets
- Claim 1 restricts lubricant to calcium stearate/magnesium stearate or talc/sodium stearyl fumarate with specific ranges.
- It restricts diluent to microcrystalline cellulose and D-mannitol with 3–10 wt%.
- Substituting outside the listed families risks avoiding the claim even if the composite portion matches.
-
Avoid hydroxypropyl cellulose constraint
- Claim 1 requires hydroxypropyl cellulose 0–4 wt%. A formulation exceeding this could avoid Claim 1.
-
Avoid salt identity in dependent claims
- Claim 9 specifically requires the dihydrochloride salt. A different salt (or free base) could avoid Claim 9, though it may not avoid Claim 1.
Patent landscape: How to position 9,675,549 in a freedom-to-operate view
1) This is a formulation patent, not a compound claim
The claims recite a tablet with a composite and specified excipient system. That places the patent in the formulation/process and solid-form/carrier layer rather than core structural chemical IP.
Business implication: If a competitor already has rights to the API itself (via ownership or license) or uses a different compound structure, they can still face risk if they adopt the specific composite formulation.
2) Dependent claims create multiple infringement theories
There are separate dependent paths for:
- coat vs uncoated (Claims 4-5)
- composite ratio 1:10 (Claim 6)
- composite preparation (spray-dried or lyophilized) (Claims 7-8)
- specific salt form (Claim 9)
This structure increases litigation flexibility for the patentee: proof can be targeted to one or more narrower embodiments even if other variables differ.
3) The composite term links to both composition and manufacturing identity
Because the claim requires a composite at a specified ratio, a central landscape issue is whether the competing product’s “complex” or “inclusion” approach actually meets the claimed composite definition and ratio.
For technical challenges, the strongest evidence typically comes from characterization (e.g., HPβCD complex formation quantification) and manufacturing documentation tying the solid composite to spray drying or lyophilization if those dependent claims are asserted.
Scope summary: What the patent protects in plain product terms
US 9,675,549 protects a tablet where:
- the API is the specified urea-structured compound (or salt), and
- the API is present as an HPβCD composite with ratio 1:8 to 1:20,
- the composite makes up at least ~85 wt% of tablet weight, and
- excipients are selected from narrow lists with specific loading windows:
- lubricant: stearate or talc/fumarate with defined ranges
- diluent: microcrystalline cellulose or D-mannitol at 3 to 10%
- hydroxypropyl cellulose: 0 to 4%
With further coverage in dependents for:
- magnesium stearate ~1% and diluent 4–7.5% (Claim 2)
- film-coated tablets (Claims 4-5)
- HPβCD ratio fixed at 1:10 (Claim 6)
- spray-dried vs lyophilized composite (Claims 7-8)
- dihydrochloride salt form (Claim 9)
Key Takeaways
- Claim 1 is the anchor: infringement hinges on (a) the specific API/salt, (b) HPβCD composite ratio 1:8 to 1:20, (c) composite loading ≥ about 85 wt%, and (d) constrained lubricant/diluent/hydroxypropyl cellulose ranges.
- Dependent claims add multiple proof paths but do not replace Claim 1. A product meeting Claim 1 can still face liability even if it avoids one dependent narrowing (like the 1:10 ratio).
- Most viable design-arounds are quantitative: move outside the HPβCD ratio window or reduce composite content below ~85 wt%, or change excipient choices/ranges such that they fall outside the enumerated sets.
- Coating and composite preparation are handled in dependents, so technical documentation and characterization become pivotal if those dependents are asserted.
FAQs
1) Is US 9,675,549 a compound patent or a formulation patent?
It is a tablet formulation patent: the claims focus on a tablet containing a specific API (or salt) as an HPβCD composite plus defined excipient constraints.
2) What is the main numeric threshold that controls Claim 1?
The composite loading: about 85 wt% or more of the tablet’s total weight.
3) Can a product infringe if its HPβCD ratio is not 1:10?
Yes. Claim 1 covers 1:8 to 1:20. Claim 6 is narrower at 1:10, but it is not required for Claim 1 coverage.
4) Do spray-dried and lyophilized matter for infringement?
They matter for dependent claims (Claims 7-8). Claim 1 does not require a specific composite preparation method.
5) Does using the dihydrochloride salt automatically trigger all claims?
No. Claim 9 specifically requires dihydrochloride, but Claim 1 only requires the API to be the claimed urea compound or a pharmaceutically acceptable salt, plus the composite and excipient constraints.
References
[1] US Patent 9,675,549 (claims as provided by user input).
