United States Patent 5,962,014 (Cyclosporin Oral Microemulsion) claims scope, coverage map, and US patent landscape
US 5,962,014 is a composition-and-method patent centered on an orally administered cyclosporin A (CsA) formulation that self-forms an oil-in-water microemulsion on dilution with water, with tightly constrained excipient classes and particle-size targets. The claim set is structured to capture (i) the administration of such a formulation to a “patient in need of cyclosporin therapy,” (ii) dosing aimed at reducing variability in bioavailability, and (iii) the oral composition itself.
What does US Patent 5,962,014 actually claim: the core microemulsion architecture?
Core requirement across the independent themes: the formulation contains CsA plus three excipient buckets and, upon dilution, spontaneously forms an oil-in-water microemulsion with substantially small particles.
Claim “spine” (language you can use for freedom-to-operate mapping)
Across independent claim families, the composition/method requires:
- Cyclosporin A: about 5 to about 25% by weight
- Hydrophilic component (other than hydrophilic surfactant): about 0.5 to about 90% by weight
- Lipophilic component: about 0.5 to about 90% by weight
- Hydrophilic surfactant (other than hydrophilic component): about 0.5 to about 90% by weight
- Self-emulsification trigger: dilution with water at either:
- 1 part formulation : 5 parts water (microemulsion having particles < 2,000 Å)
- or 1:1 in several dependent versions
- Particle size limits:
- “particles of less than 2,000 Å” (key quantitative anchor)
- dependent refinements to:
- maximum size < 1,500 Å
- maximum size 100 to 1,000 Å
- average particle size < about 1,500 Å
- average particle size < about 1,000 Å
- average particle size 150 to <1,000 Å
Why the “spontaneously formed microemulsion” limitation is the gating issue
For infringement/avoidance, the patent forces the accused formulation to do more than “contain” surfactants and oils. It must spontaneously generate an oil-in-water microemulsion on dilution with water at the claimed ratios and achieve the claimed particle size window.
That means particle-size measurement methodology, dilution conditions, and whether the system is truly microemulsion (vs emulsion/suspension) become central in any contest over scope.
Which parts of the claim are strongest for enforcement: patient dosing, variability, or composition?
Most enforceable hook is the composition and its dosing conditions: Claims 1/8/15/22 are method-of-administration forms, but the independent composition claims (29 and 36) are direct and do not require proving patient identity beyond “oral pharmaceutical composition.”
Method claims (1, 8, 15, 22): what triggers infringement
These require:
- Oral administration
- To a patient “in need of cyclosporin therapy”
- Using a composition meeting all excipient-weight constraints
- Such that the microemulsion forms at the specified dilution ratio and particle size
The “reducing variability of bioavailability levels” language (claims 15 and 22 families) adds a functional/clinical purpose, but the technical infringement still depends on whether the administered formulation falls within the microemulsion and composition parameters.
Composition claims (29 and 36): what triggers infringement
These are broader because they claim the product structure and performance upon dilution without requiring:
- A particular patient outcome
- The “bioavailability variability reduction” purpose wording
If a product meets the defined CsA and excipient proportions and is designed such that dilution yields the microemulsion with the claimed particle size, these composition claims are the first line.
How broad are the excipient ranges: what can a generic or reformulation change and still infringe?
The excipient categories are defined at a high level, with wide ranges. The patent does not lock to specific named excipients in the claim text you provided. The breadth is therefore mainly constrained by:
- the CsA weight % window (5–25%)
- the bucketed ranges for each component (each 0.5–90% depending on the dependent version)
- and the microemulsion formation behavior plus particle size after dilution
Practical breadth implications
- A formulation can vary widely in the actual chemical identity within each bucket, as long as it can still self-form the microemulsion at the claimed dilution ratio and particle-size window.
- Because three large buckets each allow up to 90% in various dependent configurations, many different mixture compositions can satisfy the numeric ranges.
Dependent claim “tighteners” that narrow substitutes
Several dependent claims narrow on:
- particle size:
- <1,500 Å vs <2,000 Å
- average vs maximum size distinctions
- size windows like 100–1,000 Å and 150–<1,000 Å
- dilution ratio:
- adding an explicit 1:1 dilution route
The critical non-numeric limitation: “hydrophilic surfactant other than the hydrophilic component”
This bifurcation can matter for design-around:
- If an excipient performs both “hydrophilic component” and “hydrophilic surfactant” functions, classification disputes can arise.
- The claim language attempts to prevent double-counting by separating the hydrophilic component from the hydrophilic surfactant category.
What particle-size terms control scope: microemulsion particle “less than” vs “average less than” and measurement risk?
The claim set uses both:
- “particles of less than 2,000 Å”
- “particles have a maximum size of less than 1,500 Å”
- “average particle size of less than about 1,500 Å”
- “average particle size less than about 1,000 Å”
- explicit average size ranges (150 to <1,000 Å)
Why this matters for infringement assessment
Different analytical techniques (DLS vs other sizing methods) and different reporting conventions can shift “average” vs “maximum” values. Scope is tied to the claim’s performance results after the defined dilution ratio.
From a litigation or licensing perspective, this is a practical lever: a formulation that stays numerically above one threshold but stays within others may still fall outside, depending on which dependent claim is asserted and how sizing is construed.
How does the patent frame dilution: 1:5 vs 1:1 and what that does to design-around
Across the family:
- Key independent structure includes dilution to 1 part by weight composition : 5 parts by weight water
- Dependent versions also claim dilution to 1:1 in several method and composition claim variants
Design-around signal
If a competitor’s administration method uses a different dilution scheme (or relies on a premixed form where the claimed dilution step is not performed), they may avoid literal infringement. Still, if the product is administered and results in the claimed microemulsion behavior upon patient-level dilution, the argument shifts to whether the claimed “upon dilution” conditions are met in practice.
What is claimed about “reducing variability of bioavailability levels”: is it a method-of-treatment limitation or a performance proxy?
Claims 15 and 22 add:
- “reducing the variability of bioavailability levels of cyclosporin A for patients during cyclosporin therapy”
This is a treatment goal. However, the claim still recites the same formulation and microemulsion formation parameters. So the clinical language likely functions as:
- an additional limiting purpose tied to administration of the claimed formulation, not a separate technical mechanism.
In practical terms, infringement will still focus on:
- whether the administered formulation contains CsA and excipients in the claimed ranges
- and whether it yields the required microemulsion particle size at the claimed dilution ratio
What are the composition claims (29 and 36) designed to cover: dosage form, route, and systemic exposure
The claim language you provided frames:
- oral pharmaceutical composition
- with the microemulsion formed on dilution in water
The patent text is not limited to capsules/tablets in the claim excerpt you provided; instead it defines a composition as a mixture that performs upon dilution. That can capture multiple oral presentation formats, including:
- concentrates for dilution
- oral liquids
- dispersible systems, if water dilution leads to the claimed microemulsion behavior
How many distinct “families” of coverage does the claim set create?
Based on the excerpt, there are three coverage clusters:
- Method of oral administration to cyclosporin-therapy patients (claims 1 and 8)
- Method of reducing variability of bioavailability in cyclosporin therapy (claims 15 and 22)
- Oral pharmaceutical compositions (claims 29 and 36)
Each cluster is parameterized by:
- CsA % range (5–25%)
- excipient bucket ranges
- microemulsion formation upon water dilution
- particle size thresholds (2,000 Å baseline; then tighter dependent windows)
US patent landscape: what matters for this specific patent (but requires record data not provided)
A complete “US patent landscape” for US 5,962,014 requires, at minimum, the patent bibliographic record and its cited references and family members (continuations, divisionals), plus the Orange Book listing(s) for the corresponding cyclosporin product and any related ANDA/BLA challenges. Those items are not present in the prompt, and a landscape without them would not be operationally accurate.
Because sufficient information to produce an actionable landscape (expiration dates, other US patents covering the same drug product, litigation and Paragraph IV timing, Orange Book status, and competitor risk) is not available in the provided material, no landscape section is produced.
Key infringement/avoidance checklist tailored to US 5,962,014’s claim language
If evaluating whether a candidate formulation falls within scope:
- Does it contain CsA at 5–25% by weight?
- After dilution with water at 1:5 (w/w) (and/or 1:1 depending on asserted claims), does it spontaneously form an oil-in-water microemulsion?
- What particle size is achieved:
- <2,000 Å baseline
- tighter dependent targets (<1,500 Å, average and/or maximum windows like 100–1,000 Å or 150–<1,000 Å)?
- Are excipients classified as:
- hydrophilic component (excluding hydrophilic surfactant)
- lipophilic component
- hydrophilic surfactant (excluding hydrophilic component)?
- Are weight percentages calculated on total formulation weight?
If evaluating design-around:
- Move CsA outside 5–25% by weight.
- Break the spontaneous microemulsion formation under the claimed dilution ratios.
- Yield particle sizes outside the relevant thresholds for the asserted claim (especially the dependent <1,500 Å and average <1,000 Å windows).
- Change the administration/dilution process such that the claimed dilution ratios are not met in any practical use scenario.
Key Takeaways
- US 5,962,014 claims oral cyclosporin A formulations defined by CsA 5–25% (w/w) plus three excipient buckets and a required spontaneous oil-in-water microemulsion upon water dilution.
- The decisive technical limitation is particle size after dilution, with a hierarchy of thresholds: <2,000 Å baseline and dependent narrower limits around <1,500 Å, <1,000 Å, and explicit ranges like 100–1,000 Å and 150–<1,000 Å.
- Enforcement posture is anchored both in method-of-administration claims (including “reduce variability of bioavailability”) and in direct oral composition claims (29 and 36).
- Any freedom-to-operate assessment turns on whether the accused product meets the microemulsion formation + particle-size performance under the claimed dilution ratios and whether excipients can be mapped cleanly into the claim’s hydrophilic component vs hydrophilic surfactant separation.
FAQs
1) What aspect of US 5,962,014 is hardest to design around: CsA percentage or particle size?
Particle size after the claimed dilution ratio is the hardest lever because the patent ties the excipient ranges to a performance outcome: microemulsion formation with specific particle thresholds.
2) Do the “reduce variability of bioavailability” phrases change the technical infringement analysis?
They add a treatment purpose, but the claim still requires the same formulation composition and microemulsion performance limits.
3) Can a formulation avoid infringement by changing dilution from 1:5 to 1:1?
Some dependent claims explicitly include 1:1 dilution; avoiding the claimed dilution conditions can be relevant, but infringement can still occur if in-use dilution yields the claimed microemulsion behavior.
4) Are maximum particle size and average particle size interchangeable under the claims?
No. The claim set distinguishes “maximum size” and “average particle size,” and each has distinct numeric thresholds.
5) Does the claim require a specific named cyclosporin salt or specific excipient chemicals?
The excerpt defines compositional roles and weight ranges rather than named chemicals, so scope is driven by meeting the bucket categories and performance limits, not by specific excipient names (based on the claim text provided).
