US Patent 4,895,726 (Fenofibrate + Solid Surfactant Co-micronized Mixture): Scope, Claims, and US Landscape
What does US 4,895,726 claim in practical terms?
US 4,895,726 claims an orally administered therapeutic composition for hyperlipidemia/hypercholesterolemia that is built around a specific formulation architecture:
- Active: fenofibrate
- Key technology: a co-micronized mixture of fenofibrate particles and a solid surfactant
- Critical particle-size limit: mean particle size < 15 µm (and narrower dependent claim targets)
- Surfactant specificity: includes sodium lauryl sulfate (SLS) as the preferred exemplified solid surfactant
- Dosage form: gelatin capsules
- Manufacturing workflow: co-micronization followed by granulation with lactose/starch, water-assisted granulation, drying to ≤1% water, grading, then addition of polyvinylpyrrolidone (PVP) and magnesium stearate, and capsule filling
- Therapeutic intent: oral treatment of hyperlipidemia/hypercholesterolemia
- Mechanistic framing: improved bioavailability via co-micronization until the target size is reached
The independent claim set is composition-focused (claim 1) with two methods: (i) manufacturing (claim 8) and (ii) bioavailability improvement (claim 10), plus downstream treatment use (claims 11-12).
What is the scope of the independent claim(s)?
H2: Claim 1 (composition)
Claim 1 defines the core protected subject matter:
- Therapeutic composition presented as gelatin capsules
- Useful for oral treatment of hyperlipidemia and hypercholesterolemia
- Contains a co-micronized mixture of:
- fenofibrate particles and
- a solid surfactant
- Particle-size limitation: mean particle size of the co-micronized mixture is < 15 µm
Scope implications
- The claim is product-by-structure/performance proxy: it does not require a specific dissolution profile, only a mean particle size for the co-micronized mixture.
- It captures any solid surfactant that qualifies as “solid” and is used in co-micronization, subject to later dependent narrowing.
H2: Claim 8 (manufacture method)
Claim 8 protects a specific end-to-end process:
- Intimately mix fenofibrate and solid surfactant, then co-micronize
- Add lactose and starch
- Convert to granules in presence of water
- Dry granules until ≤ 1% water
- Grade granules
- Add PVP and magnesium stearate
- Fill gelatin capsules
Scope implications
- This method claim is process-specific: changing the order, omitting a step, changing excipient system (lactose/starch), changing the granulation route, or changing drying target water content can create design-around leverage.
- Co-micronization remains the center of gravity: the claim requires co-micronizing the fenofibrate/solid surfactant mixture.
H2: Claim 10 (bioavailability improvement method)
Claim 10 claims a functional method defined by the co-micronization endpoint:
- Improve bioavailability of fenofibrate in vivo
- By co-micronization of fenofibrate and a solid surfactant
- Co-micronization carried out by micronizing a fenofibrate/solid surfactant mixture
- Until particle size < 15 µm for the powder obtained
Scope implications
- This claim is endpoint-based rather than excipient-dependent, so a product maker that uses a different capsule/excipient system can still potentially fall in scope if the process creates the target < 15 µm co-micronized powder and the claim is asserted as “bioavailability improvement” use.
What do the dependent claims narrow?
H2: Particle-size narrowing
| Claim |
Additional limitations |
Effect on scope |
| 6 |
Mean particle size ≤ 10 µm AND solid surfactant is sodium lauryl-sulfate |
Narrows to finer co-micronized product plus SLS |
| 12 |
In claim 11 method (oral treatment), particle size ≤ 5 µm |
Narrows treatment method to the finest size class |
The base threshold in claim 1 is < 15 µm. The family narrows in stages: ≤10 µm (claim 6) and ≤5 µm (claim 12).
H2: Surfactant specificity
| Claim |
Surfactant limitation |
Practical effect |
| 4 |
Solid surfactant is sodium lauryl-sulfate |
Locks to SLS |
| 6 |
Requires sodium lauryl-sulfate plus ≤10 µm |
Tightest SLS + particle class |
| 2 |
Weight ratio surfactant/fenofibrate 0.75/100 to 10.5/100 |
Quantifies SLS (or other solid surfactant, depending on claim dependency) range in composition |
Because claim 1 is not limited to SLS, SLS-inclusive dependent claims matter for infringement risk in SLS formulations but do not restrict claim 1’s broader “solid surfactant” umbrella.
H2: Formulation quantity
| Claim |
Limitation |
Effect |
| 3 |
Fenofibrate amount 200 mg per therapeutic unit |
Dose-specific coverage; other strengths may evade claim 3 but still be captured by claim 1 unless dose is treated as required element (it is a dependent claim, so independent claim 1 does not require 200 mg) |
| 5 |
SLS amount 0.5% to 7% by weight of total formulation |
Useful for quantizing SLS-level infringements for SLS-based products |
H2: Treatment method use
| Claim |
Treatment scope |
Particle specificity |
| 11 |
Oral administration of therapeutic composition of claim 6 to a patient |
Uses claim 6 constraints, so SLS and ≤10 µm in that dependent chain |
| 12 |
Same as claim 11 but particle size ≤5 µm |
Tightest “treatment” boundary |
How the claims relate (claim dependency map)
- Claim 1: composition core (gelatin capsules, co-micronized fenofibrate + solid surfactant, mean size < 15 µm)
- Claims 2, 3, 4, 5, 6, 7 add constraints
- Claim 6: adds SLS and mean size ≤10 µm
- Claim 2: adds surfactant/fenofibrate weight ratio (0.75/100 to 10.5/100)
- Claim 3: adds 200 mg fenofibrate per unit
- Claim 5: adds SLS 0.5% to 7% by weight
- Claim 7: adds excipients (generic)
- Claim 8: manufacturing method of claim 1 composition (full workflow)
- Claim 9 adds: mean size < 15 µm for co-micronized fenofibrate + SLS
- Claim 10: method for improving bioavailability (endpoint-based < 15 µm co-micronized mixture powder)
- Claim 11: treatment method by administering claim 6 composition
- Claim 12 adds: particle size ≤5 µm
What does “co-micronized mixture” do to infringement analysis?
The claims hinge on a specific physical condition: the co-micronized mixture of fenofibrate and solid surfactant with a mean particle size limit.
Operationally, infringement analysis will tend to focus on:
- Whether fenofibrate and surfactant are actually co-micronized together (not simply blended afterward)
- Whether the resulting powder meets the mean particle size requirement (and which size distribution metric is used in practice)
- For SLS dependent claims, whether the surfactant is sodium lauryl sulfate and whether loading matches the dependent range
US patent landscape: how to map competitive risk around the claim structure
A credible US landscape view has to be framed around four “design-around levers” visible in the claim text.
1) Particle-size threshold design-around
- Protected thresholds:
- claim 1 and claim 10: mean particle size < 15 µm
- claim 6: mean particle size ≤ 10 µm (SLS)
- claim 12: particle size ≤ 5 µm (treatment)
Landscape effect
- Formulations with co-micronized fenofibrate + solid surfactant that result in mean sizes at or above 15 µm reduce risk against the broadest endpoint claims.
- Intermediate sizes (for example, 10 to 14.9 µm) can still create exposure to claim 1 but not necessarily to the narrower claim 6 class.
2) Surfactant identity design-around
- Broad: claim 1 covers any solid surfactant
- Narrow: claim 4/5/6/9/11/12 restrict to sodium lauryl sulfate
Landscape effect
- Switching from SLS to another solid surfactant is not a guaranteed carve-out because claim 1 can still cover other solid surfactants if the co-micronization and particle-size limitations are met.
- A true carve-out requires changing either:
- surfactant type so it does not meet the claim’s “solid surfactant” definition, or
- the process so it does not create the protected mean particle size distribution.
3) Process-flow design-around
Claim 8 protects a granular, excipient-and-process route:
- lactose + starch granulation with water
- drying until ≤1% water
- PVP + magnesium stearate
- gelatin capsule filling
Landscape effect
- Competitors can attempt to avoid this specific manufacturing method claim by using an alternative processing sequence or alternative granulation system (without implicating co-micronization + endpoint claims).
4) Functional method design-around (bioavailability)
Claim 10 protects “improving bioavailability” via a process endpoint (<15 µm powder).
Landscape effect
- Even if a competitor avoids the manufacturing steps of claim 8, claim 10 is process-outcome oriented. If they create co-micronized powder with the endpoint particle size and intend/perform the bioavailability improvement, exposure can remain.
Key claim-by-claim risk signals for a US entrant
H2: Most infringement-attractive claim clusters
-
SLS + capsule + co-micronized powder size < 15 µm
- Targets claim 1 plus likely dependent claim 4/5, depending on SLS loading and particle size.
-
SLS + capsule + ≤10 µm
- Targets claim 1 plus dependent claim 6; treatment risk increases via claim 11.
-
SLS + ≤5 µm treatment formulations
- Targets claim 12 directly for oral administration use where the particle size is ≤5 µm.
-
Manufacturing route matching claim 8
- Targets the method of manufacture if the full sequence and drying target are used.
-
Bioavailability improvement via <15 µm co-micronized powder
- Targets claim 10 if the process endpoint is met.
H2: Most common design-around patterns
- Avoid co-micronization endpoint: create co-processed material but keep mean size ≥15 µm for the co-micronized mixture.
- Avoid the excipient granulation workflow: replace lactose/starch water granulation and/or alter drying target so the claim 8 sequence is not met.
- Avoid SLS: reduce risk against SLS-dependent claims, but not necessarily claim 1 if another solid surfactant still results in <15 µm co-micronized mixture.
What is the breadth gap between composition and methods?
- Composition claim (1): focuses on final product characteristics (capsule, co-micronized mixture, mean < 15 µm).
- Manufacturing claim (8): focuses on the specific manufacturing workflow.
- Bioavailability method (10): focuses on a process endpoint rather than the final capsule excipient system.
A company can avoid claim 8 but still face claim 1 and claim 10 risk if the final product or the intermediate powder falls into the protected size window.
Key Takeaways
- US 4,895,726 is centered on fenofibrate co-micronized with a solid surfactant into a capsule-ready powder with mean particle size < 15 µm.
- The claim set creates layered exposure:
- broadest: <15 µm (claim 1, claim 10)
- narrower with SLS: ≤10 µm (claim 6; treatment chain claim 11)
- narrowest: ≤5 µm treatment (claim 12)
- A specific manufacturing method is protected (claim 8) including lactose/starch granulation with water and drying to ≤1% water, followed by PVP + magnesium stearate and gelatin capsule filling.
- Competitive risk is driven by four levers: mean particle size endpoint, solid surfactant identity (SLS vs other), co-micronization implementation, and whether the manufacturing workflow matches claim 8.
FAQs
1) Does claim 1 require sodium lauryl sulfate?
No. Claim 1 requires a solid surfactant. Sodium lauryl sulfate appears in dependent claim 4 and constrains dependent claim 6 and downstream treatment claims.
2) What particle-size thresholds matter most?
The key limits are mean <15 µm (claim 1 and claim 10), mean ≤10 µm (claim 6), and ≤5 µm (claim 12).
3) Is the invention about tablets or capsules?
The composition is presented as gelatin capsules (claim 1) and claim 8 ends in filling gelatin capsules.
4) Can a different manufacturing process avoid infringement?
It can reduce risk against the specific method of manufacture in claim 8, but claim 1 and claim 10 remain focused on co-micronized mixture particle size (<15 µm) and may still be relevant.
5) What excipients are explicitly required in the manufacturing claim?
Claim 8 explicitly includes lactose, starch, and later PVP and magnesium stearate, with water granulation and drying to ≤1% water.
References
[1] United States Patent 4,895,726.
