United States Patent 9,962,336: Stable Extended-Release Reconstituted Powder for Suspension With Osmolality-Stabilized Release
United States Patent 9,962,336 claims a formulation system for a stable extended-release reconstituted powder for suspension. The claims center on (1) multiple coated cores (layered active on an inert particle) with release-controlling agents; (2) reconstitution stability for at least seven days with a substantially similar in-vitro dissolution profile; and (3) a reconstitution suspension base defined by viscosity and osmolality thresholds, tied to an internal-phase osmolality concept that reduces leaching from coated cores.
What is claimed in U.S. Patent 9,962,336 (claim set scope)?
Core independent claim (Claim 1)
Claim 1 defines the invention as a specific class of multipart system:
-
Dosage form / format
- “stable extended release reconstituted powder for suspension composition”
- reconstituted with a suspension base to form a suspension
-
Active delivery architecture
- composition includes “multiple coated cores of an active ingredient”
- coated cores have:
- a core of the active ingredient layered onto an inert particle
- a coating layer comprising “one or more release-controlling agents”
- average coated-core diameter: 150 μm to 500 μm
- “active ingredient is not bound to an ion-exchange matrix”
-
Reconstitution stability requirement
- upon reconstitution, composition ensures:
- “substantially similar in-vitro dissolution release profile of the active ingredient”
- after storage for at least seven days (post-reconstitution)
-
Suspension base operating constraints
- suspension base has:
- (i) viscosity: about 500 cps to about 15,000 cps
- (ii) osmolality: at least 1 osmol/kg
- The composition upon reconstitution has:
- osmolality ratio ≥ about 1
- ratio defined as:
external phase osmolality / internal phase osmolality
- external phase = suspension base without coated cores
internal phase = coated cores suspension phase
-
Internal-phase osmolality and leaching threshold
- “osmolality of the internal phase” is the osmolality of a solution that prevents significant leaching
- significant leaching threshold:
- >20% of active ingredient leached from coated cores into the solution
-
Coating identity is not limited to specific chemistries in Claim 1
- specific release-controlling agents appear in dependent claims (Claims 6-8)
- inert particle selection appears in Claim 3
Dependent claim expansions
Claim 2-10 add sub-scopes that narrow or define material classes used in the suspension base and coating selection.
| Claim |
Subject matter |
Key limiting parameters |
| 2 |
Suspension base composition |
suspending agent + osmogent + aqueous vehicle |
| 3 |
Inert particle for coated-core core |
non-pareil seed; microcrystalline cellulose sphere; dibasic calcium phosphate bead; mannitol bead; silica bead; tartaric acid pellet; wax based pellet |
| 4 |
Osmogent selection |
carbohydrates; salts of inorganic/organic acids; amino acids; urea/derivatives; propylene glycol; glycerin; PEG; xanthan gum; HPMC; mixtures |
| 5 |
Suspending agent selection |
cellulose derivatives; carbomers; gums; pectin; dextran; gelatin; PEGs; polyvinyl compounds; sugar alcohols; mixtures |
| 6 |
Release-controlling agent functional categories |
pH-dependent, pH-independent, or mixtures |
| 7 |
pH-dependent release agents examples |
acrylic copolymers; cellulose acetate phthalate; cellulose acetate succinates; hydroxyalkyl cellulose phthalates/succinates; vinyl acetate phthalates/succinates; cellulose acetate trimelliate; polyvinyl derivatives; zein; shellac; mixtures |
| 8 |
pH-independent release agents examples |
cellulosic polymers; acrylic copolymers; cellulose acetate; polyethylene derivatives; PVA; PVAc; gums; lipids; fatty acids/salts/derivatives; mixture of PVAc and PVP; mixtures |
| 9 |
Active ingredient list |
extensive multi-API genus list (includes antidiabetics, antibiotics, ARBs, antihypertensives, antivirals, NSAIDs, psych/CNS, GI, respiratory, etc.) |
| 10 |
Additional excipients in suspension base |
anti-caking; wetting; preservatives; buffering; flavoring; antioxidants; chelators; solubility enhancers; pH modifiers; adsorbents; complexing agents; combinations |
Where is the novelty anchored: formulation architecture vs. reconstitution environment?
Formulation architecture (multipart coated core system)
Claim 1 requires:
- layering active ingredient onto an inert particle to form the core
- applying a coating layer with release-controlling agents
- coated-core particle size 150-500 μm
- active not bound to an ion-exchange matrix (exclusion)
This is the backbone that makes release controllable and makes post-reconstitution leaching measurable.
Reconstitution environment (viscosity + osmolality + osmolality ratio + leaching threshold)
The claim ties stability to a reconstitution medium with:
- defined viscosity range (500-15,000 cps)
- defined osmolality minimum (≥1 osmol/kg)
- an explicit external/internal osmolality ratio ≥ 1
- an explicit leaching control concept:
- significant leaching is more than 20%
- internal phase osmolality must match a solution that prevents that level of leaching
The stability mechanism is claimed through measurable physicochemical constraints rather than solely through coating chemistry or binder selection.
How broad are the claim terms in practice?
Broadest structural breadth
-
Release-controlling agents (functional genus)
- Claim 6 covers both pH-dependent and pH-independent release systems
- dependent claims 7-8 list numerous representative polymers/resins
-
Active ingredient coverage
- Claim 9 enumerates a large API list (dozens), spanning multiple therapeutic classes.
- This signals the claim is designed to cover a technology platform across different actives.
-
Suspension base component flexibility
- Claim 2 limits the base to:
- suspending agent + osmogent + aqueous vehicle
- Claims 4 and 5 provide broad lists for both components.
- Claim 10 adds broad categories of excipients.
Narrowest structural breadth
-
Coated-core sizing
- coated cores must average 150-500 μm diameter.
-
Ion-exchange matrix exclusion
- Claim 1 requires active not bound to an ion-exchange matrix.
- This limits coverage versus known ion-exchange based controlled release systems.
-
Stability duration
- the in-vitro dissolution profile must remain “substantially similar” after storage for at least seven days post-reconstitution.
-
Leaching threshold
- stability is tied to preventing >20% leaching.
Patent landscape implications for U.S. Patent 9,962,336
Claim coverage map (what competitors must avoid or redesign)
Competitors seeking to launch similar reconstituted extended-release suspensions must evaluate four risk clusters:
-
Coated-core multipart architecture
- multiple coated cores
- layered active on inert particles
- release-controlling coating layer
- 150-500 μm average coated core size
-
Reconstitution stability benchmark
- substantially similar dissolution profile after ≥7 days storage post-reconstitution
-
Suspension base physicochemical window
- viscosity 500-15,000 cps
- osmolality ≥1 osmol/kg
- osmolality ratio external/internal ≥1
-
Leaching behavior
- avoid conditions where significant leaching exceeds 20%
Legal “attack surfaces” likely used in freedom-to-operate analysis
From the claim text alone, the most plausible non-infringing design routes are:
- Change coated-core size outside 150-500 μm (e.g., smaller or larger average distribution).
- Use an ion-exchange matrix if commercially and scientifically feasible (but note Claim 1 affirmatively excludes ion-exchange binding).
- Alter the osmolality ratio by engineering internal phase vs external phase osmolality to fall below the ≥1 threshold.
- Alter reconstitution medium viscosity outside 500-15,000 cps or osmolality below 1 osmol/kg.
- Allow >20% leaching (then the product no longer meets the claimed “prevents significant leaching” requirement, though regulators may reject performance failures).
- Fail the ≥7-day post-reconstitution dissolution similarity criterion by allowing dissolution drift or leaching over that window.
Claims-by-design: how to read infringement risk term-by-term
Term-by-term checklist for Claim 1
A product is within Claim 1 if it satisfies each element simultaneously:
- Dosage form is a “reconstituted powder for suspension” with extended release.
- The powder contains multiple coated cores.
- Each coated core contains:
- active layered onto an inert particle core
- coating layer with release-controlling agent(s)
- average diameter 150-500 μm
- The active is not bound to an ion-exchange matrix.
- After reconstitution and ≥7 days storage:
- dissolution profile is “substantially similar.”
- The suspension base for reconstitution has:
- viscosity 500-15,000 cps
- osmolality ≥1 osmol/kg
- After reconstitution:
- osmolality ratio ≥1, defined as:
- external phase osmolality / internal phase osmolality
- Internal phase osmolality is of a solution that prevents:
- leaching ≤20%
- (significant leaching is >20%)
Dependent claims function as claim “multipliers” rather than new architecture
Claims 2-5 and 7-8 further constrain component selection but do not replace the Claim 1 architecture. Claim 10 broadens excipient tolerance in the suspension base.
Material ranges likely used to prove or disprove claim scope
| Feature |
How it constrains products |
| Viscosity |
Forces selection of suspending system into a narrow operational band |
| Osmolality |
Forces osmogent choice and concentration into an osmolality-minimum region |
| Osmolality ratio |
Forces matching between coated-core internal solution characteristics and external formulation characteristics |
| Release-controlling agent class |
pH-dependent vs pH-independent categories expand coverage; polymer family lists provide proof examples |
| Leaching threshold |
Creates an objective physicochemical performance requirement |
Where the platform concept sits vs known suspension technologies
The claim language combines:
- coated controlled-release cores (multipart beads/seeds with polymer coatings)
- with a reconstitution medium defined by osmolality and viscosity
- with dissolution stability tied to inhibition of active leaching above 20%
This combination matters for landscape mapping because it suggests a technology pivot away from only coating selection and toward reconstitution-medium physicochemical conditioning.
Key Takeaways
- U.S. Patent 9,962,336 claims a platform for stable extended-release reconstituted suspensions built on multiple coated cores (150-500 μm) with release-controlling coatings and a reconstitution base governed by viscosity (500-15,000 cps) and osmolality (≥1 osmol/kg).
- The claim adds performance constraints that are likely to be decisive in litigation and design-around:
- substantially similar dissolution after at least 7 days post-reconstitution
- osmolality ratio external/internal ≥1
- leaching control with a “significant leaching” threshold defined as >20%.
- Dependent claims widen practical coverage by enumerating broad classes for suspending agents, osmogents, release-controlling agents, excipients, and a long active-ingredient list, while still enforcing the Claim 1 architecture and physicochemical windows.
FAQs
1. What is the main inventive constraint in Claim 1?
A suspension base with defined viscosity and osmolality, tied to an external/internal osmolality ratio ≥1 that prevents leaching above 20% from coated cores over storage, while maintaining dissolution similarity after 7 days.
2. What particle-size requirement controls the coated core?
Claim 1 requires coated cores with average diameter 150 μm to 500 μm.
3. Does Claim 1 require a specific release polymer chemistry?
No. Claim 1 requires release-controlling agents, while Claim 6-8 provide example categories and lists for pH-dependent and pH-independent release agents.
4. Can the suspension base include typical excipients?
Yes. Claim 10 allows additional pharmaceutically acceptable excipients in broad categories (anti-caking, wetting, preservatives, buffering, flavoring, antioxidants, chelators, pH modifiers, adsorbents, complexing agents).
5. How does the patent handle ion-exchange controlled release systems?
Claim 1 excludes embodiments where the active ingredient is bound to an ion-exchange matrix.
References
[1] United States Patent 9,962,336, “Stable extended release reconstituted powder for suspension composition,” claim set as provided in prompt.
