|
Patent landscape, scope, and claims: |
United States Patent 5,785,994: Scope, Claim Architecture, and U.S. Landscape
US Patent 5,785,994 claims a class of GI-delivered osmotic dosage forms/devices that create a drug-free interval before therapeutic drug release. The claims are written around a specific mechanical sequence: (i) an osmotic device is placed in the gastrointestinal tract; (ii) fluid enters; (iii) an expanding third composition drives/pressurizes a second drug-containing composition; (iv) drug delivery begins only after a drug-free first composition is released, generating a controlled lag and then continuous or at-least-once-daily dosing.
1) What is the invention’s claimable core?
Across the independent claim (and its dependent fall-through), the invention’s scope is anchored to a combination of structural and functional limitations:
A. Device architecture
Each representative claim recites an osmotic device with:
- Compartment
- Fluid-permeable wall (“a wall… comprising a composition that is permeable to the passage of fluid”)
- Exit means in the wall for connecting device exterior to the compartment
- Third composition in the compartment that:
- “expands in the presence of fluid that enters the device”
- “push[es] against the second composition” after imbibition
B. Release choreography (drug-free interval)
Each representative claim also requires:
- A first composition that is drug-free
- The first composition produces a “drug-free interval” “prior to the administration of drug from the compartment”
- Delivery of the second composition drug occurs after the drug-free interval (i.e., after at least some/all of the first drug-free composition is released)
C. Imbibition-triggered pumping
The claims require the sequence:
- “imbibing fluid into the compartment” causes the third composition to expand
- the expanded third composition pushes on the drug-containing second composition
- the drug-containing second composition is then administered after the drug-free first composition has cleared
This combination is the primary claim “engine”: the patent is not limited to any one drug; it is limited to a particular osmotic, multilayer/three-composition pressure-push design that produces a controlled pre-dose window.
2) How broad is claim coverage? (Independent vs. dependent)
The claim set (as provided) shows breadth in two axes: drug substitutability and therapeutic category coverage.
Claim 1: Early generic anchor
Claim 1 is the foundational method claim for a GI-delivered osmotic device with:
- First composition drug-free; produces drug-free interval
- Second composition drug selected from a defined list including:
- Verapamil, nimodipine, nitrendipine, nisoldipine, nicardipine, felodipine, diltiazem, lidoflazine, tiapamil, guanabenz, isradipine, gallopamil, amlodipine, mioflazine, caroverene
- and includes specific salts such as diltiazem hydrochloride
- and midazolam
- Third composition expansion in response to fluid entry
- Wall permeable to passage of fluid
- Exit means and imbibition pushing mechanics
- Administer second composition “after the first drug-free composition is released”
Claim 1 also defines a first composition viscosity range:
- 100 centipoises to 10,000,000
This viscosity feature is a meaningful structural/functional constraint because it ties the drug-free composition behavior to the claimed interval generation.
Claim 3: Broadens drug universe to a pharmacology genus
Claim 3 keeps the same mechanics but expands the drug second-composition selection to a much broader functional class:
- “drugs that act on peripheral nerves”
- “adrenergic receptors”
- “cholinergic receptors”
- “nervous system”
- “skeletal muscles”
- “cardiovascular system”
- “smooth muscles”
- “blood circulatory system”
- multiple receptor/site/junction/hormone/immunological system terms
- “histamine systems”
- and more
This is a significant widening relative to Claim 1’s named list.
Claim 4: Further expands to explicit therapeutic classes
Claim 4 tightens the genus structure to enumerated therapeutic areas:
- anticonvulsants, analgesics, anti-Parkinsons, anti-inflammatories
- calcium antagonists
- anesthetics, antimicrobials, antimalarials, antiparasites
- antihypertensives, antihistamines, antipyretics
- alpha-adrenergic agonists, alpha-blockers
- biocides, bactericides
- bronchial dilators, beta-adrenergic blocking drugs
- cardiovascular drugs, calcium channel inhibitors
- diuretics, electrolytes
- and additional categories including vitamins, nonsteroidal anti-inflammatory drugs, ACE inhibitors, and polypeptide therapeutic activities
This list broadens claim coverage by capturing large standard-of-care classes within the GI osmotic platform.
Claim 5: Converts to “dosage form” framing + polymer MW constraint
Claim 5 is the “still broad, but more device-material specific” claim:
- It also requires “at least once a day” administration from a dosage form to the GI tract
- The dosage form still has:
- compartment, permeable wall, exit means
- drug-free first composition in the compartment producing a drug-free interval
- third expanding composition pushing against second drug composition
- It adds a specific material spec for the drug-free first composition:
- first composition comprises a polymer with molecular weight 9,000 to 10,000,000
It also provides a very broad “drug consisting of a member selected from the group consisting of” long-form therapeutic activity categories, including:
- anticonvulsant/analgesic/anti-Parkinson/anti-inflammatory/antimicrobial/antihypertensive/etc.
- plus sleep inducer and anorexia therapeutically active drugs
- polypeptide/proteins
Thus, Claim 5 is broad on drug category but constrained by a polymer MW range on the drug-free composition.
Claims 6 and 7: Narrow but commercially concrete anchor around verapamil
Claim 6 narrows to:
- verapamil
- second composition dose: 0.05 ng to 1.5 g verapamil
- device mechanics unchanged
- drug-free first composition preceding verapamil release
Claim 7 adds an immediate release feature:
- “substantially immediate release dose amount… on the exterior surface of the wall”
- drug on exterior wall is administered by contacting with GI fluid
This claim ties the platform to a combined immediate + osmotic-controlled component approach (surface drug plus internal osmotic lag).
Claim 2: Confirms administration from exterior of osmotic device
Claim 2 depends from Claim 1 and specifies:
- “a dose amount of drug is administered from the exterior of the osmotic device”
This reads like an additional delivery pathway limitation: the device includes external-dose administration as part of the arrangement (consistent with Claim 7’s surface dosing concept).
Claim 8: Broadens the named nitrate family
Claim 8 mirrors Claim 1’s viscosity-based first composition and otherwise similar device mechanics, but swaps in a different explicit drug list for the second composition:
- amyl nitrate, glyceryl trinitrate (nitroglycerin), octyl nitrite, sodium nitrite
- erythrityl tetranitrate, isosorbide dinitrate
- and multiple nitrate esters/polyols:
- mannitol hexanitrate, pentaerythritol tetranitrate, pentritol, triethanolamine trinitrate, and “trolnitrate phosphate”
This suggests the inventor’s practical focus includes nitrovasodilators alongside calcium channel blockers and other actives.
3) Claim scope mapping: what must be present to infringe
A practical infringement read-through requires the accused method/product to satisfy the following grouped limitations, in some combination depending on which claim is asserted:
Must-have for the “core platform”
- GI administration to a warm-blooded animal
- Placement of an osmotic device/dosage form in the GI tract with:
- compartment
- fluid-permeable wall
- exit means (connecting exterior to compartment)
- A first drug-free composition that creates a drug-free interval
- A third composition that:
- expands upon fluid entry
- pushes against the second drug composition
- A second composition containing drug (from the claim’s permitted set)
- Drug administration occurs only after the first drug-free composition is released
Additional constraints depending on claim
- Viscosity limitation (Claims 1 and 8): first composition viscosity 100 cP to 10,000,000
- Polymer molecular weight (Claim 5): first composition polymer MW 9,000 to 10,000,000
- Specific actives and amounts (Claims 6 and 7):
- verapamil dose 0.05 ng to 1.5 g
- immediate release on exterior wall (Claim 7)
- Drug universe breadth (Claims 1 vs. 3 vs. 4 vs. 5 vs. 6 vs. 8):
- Claim 1 and Claim 8 are limited to enumerated named drugs
- Claims 3-5 use broad therapeutic genus lists, with Claim 5 also broad activity categories
4) Patent landscape implications in the U.S. market
A. Where this sits in the GI osmotic delivery ecosystem
US 5,785,994 is positioned within the broad family of:
- osmotic pump drug delivery (pump-by-imbibition mechanics)
- delayed or staged release systems created by multilayer compartments
- drug-free lead-in segments to create a pre-dose window
The novelty in the claim set, as written, is the combination of:
- drug-free interval generation through a first composition
- while using a third expanding composition in response to fluid entry to push against the drug-containing second composition
B. Practical competitor design-arounds signaled by the claim structure
A design-around that avoids infringement tends to break at least one of these pillars:
- remove/alter the drug-free interval concept (eliminate the first drug-free composition, or cause drug release concurrently)
- eliminate the third expanding composition mechanism (replace with a non-expanding piston, different propulsion mechanism, or different internal response material)
- avoid the claimed material specs when asserted:
- change viscosity behavior outside 100 cP to 10,000,000 (for viscosity-limited claims)
- use polymer MW outside 9,000 to 10,000,000 (for Claim 5’s MW-limited claim)
- reduce/avoid use of actives inside the enumerated sets if the asserted claim is limited to those lists (e.g., verapamil or nitrate list)
Because Claims 3-5 expand drug category coverage broadly, avoiding named drugs alone may not clear infringement risk if the asserted claim targets the platform mechanics rather than the drug list.
5) Claim-by-claim scope snapshot (from provided text)
| Claim |
GI delivery method |
Osmotic device elements |
Drug list / class |
Material limitation(s) |
Release pattern constraint |
| 1 |
Warm-blooded GI administration |
permeable wall, exit means, compartment, third expanding composition pushes second |
Named list incl. verapamil, nimodipine, nitrendipine, nisoldipine, nicardipine, felodipine, diltiazem, lidoflazine, tiapamil, guanabenz, isradipine, gallopamil, amlodipine, mioflazine, caroverene, diltiazem HCl, midazolam |
First composition viscosity 100 cP to 10,000,000 |
Drug-free interval from first composition before second drug release |
| 2 |
Depends on 1 |
Same |
Same |
None stated |
Administer dose “from exterior of osmotic device” |
| 3 |
Warm-blooded GI administration |
Same |
Broad pharmacology genus (peripheral nerves, adrenergic, cholinergic, etc.) |
None stated |
Drug-free interval before drug administration |
| 4 |
Depends on 3 |
Same |
Broad therapeutic classes list |
None stated |
Drug-free interval |
| 5 |
At least once/day |
Dosage form framing; same osmotic elements |
Very broad drug activity categories (includes proteins/polypeptides, sleep inducer, anorexia therapeutically active drugs) |
First composition polymer MW 9,000 to 10,000,000 |
Drug-free interval before administering drug |
| 6 |
At least once/day |
Same |
Verapamil |
Verapamil dose 0.05 ng to 1.5 g |
Verapamil released after first drug-free composition |
| 7 |
Depends on 6 |
Same plus exterior surface dosing |
Verapamil |
None stated beyond Claim 6 |
“Substantially immediate release” dose on exterior surface; contact with GI fluid |
| 8 |
Warm-blooded GI administration |
Same as 1 |
Named nitrate family list |
First viscosity 100 cP to 10,000,000 |
Drug-free interval then nitrate drug release |
6) Business relevance: how to use this claim set in diligence
A. If you are assessing infringement risk
Your claim-level checklist should follow the order below:
- Is the platform an osmotic device with fluid-permeable wall and internal imbibition?
- Does it contain a drug-free first composition that creates a drug-free interval before the therapeutic drug appears?
- Does it use a third composition that expands upon fluid entry to push against the drug-containing second composition?
- What drug is delivered:
- If the asserted claim is Claim 1 or Claim 8 or Claim 6, actives must match the enumerated list or verapamil dose constraint.
- If the asserted claim is Claim 3-5, focus shifts to whether the drug falls within the functional/class language.
- Does the formulation use:
- first composition viscosity 100 cP to 10,000,000 (Claim 1/8), or
- first composition polymer MW 9,000 to 10,000,000 (Claim 5)?
B. If you are assessing freedom-to-operate strategy
The claim drafting indicates FTO leverage comes from:
- mechanical divergence (remove expanding third composition or change propulsion physics)
- pharmacological divergence (unclear clearing if broad therapeutic genus claims are used)
- formulation divergence (tune or replace the drug-free first composition properties so the viscosity/MW limitations cannot be met if those dependent claims are asserted)
- release choreography divergence (remove drug-free interval staging)
Key Takeaways
- US 5,785,994 claims GI administration using an osmotic device with a fluid-permeable wall, exit means, and a three-composition compartment where a drug-free first composition creates a drug-free interval before drug release.
- The mechanism centers on a third composition that expands when GI fluid enters and pushes against a drug-containing second composition.
- Drug scope is layered: narrow enumerated lists (Claims 1, 6, 8) coexist with broad therapeutic genus lists (Claims 3-5).
- Claim breadth depends on technical constraints on the drug-free first composition:
- viscosity 100 cP to 10,000,000 (Claims 1 and 8)
- polymer molecular weight 9,000 to 10,000,000 (Claim 5)
- Verapamil coverage includes both an internal osmotic release mechanism (Claim 6) and an added substantially immediate release external surface dosing concept (Claim 7).
FAQs
1) Is the patent limited to one drug?
No. Claim coverage spans named drugs (Claims 1, 6, 8) and broad therapeutic/function categories (Claims 3-5).
2) What is the critical novelty element in the claim set?
The combination of a drug-free first composition that creates a drug-free interval plus a third expanding composition that drives the second drug composition via osmotic fluid entry.
3) What formulation specs can narrow infringement analysis?
For the provided claims: first composition viscosity (100 cP to 10,000,000) in Claims 1 and 8, and polymer molecular weight (9,000 to 10,000,000) in Claim 5.
4) Does verapamil have its own dedicated claim set?
Yes. Claims 6 and 7 specifically cover verapamil and include a 0.05 ng to 1.5 g dose range plus a substantially immediate release exterior surface feature in Claim 7.
5) How does the “at least once a day” language affect scope?
It frames the method outcome (GI administration at least once daily) in Claims 5-7, while the osmotic mechanism and drug-free interval requirements still control the platform scope.
References
[1] United States Patent 5,785,994.
More… ↓
⤷ Start Trial
|
