United States Patent 5,690,923: Scope of Claims and Patent Landscape for a Topical Retinoid-Aqueous, Non-Ionic Surfactant Formulation
What does US 5,690,923 claim in scope?
US Patent 5,690,923 claims a topical skin composition built around three tightly coupled formulation constraints:
1) Active class: a retinoid
2) Vehicle system: an aqueous vehicle with controlled pH (3 to 7)
3) Stabilization mechanism: inclusion of at least one non-ionic surfactant that is characterized as a crystallization preventing and stabilizing agent for the retinoid, with the surfactant limited to specific polymeric/non-ionic families and examples.
The patent also introduces optional features that narrow or expand coverage: optional organic solvent (up to 5 wt%), optional additional non-ionic surfactant, optional antibiotic (including clindamycin), and specific organic solvent definition (monohydric C1–C3 alkanol).
The practical claim scope is therefore a formulation product claim centered on the combination of retinoid + aqueous vehicle + pH window + selected non-ionic surfactant stabilization families, with optional add-ons.
Claim 1: the core independent claim and what it covers
Claim 1 (independent)
A composition for topical application to the skin comprising:
Coverage logic: Infringement requires all elements of Claim 1: retinoid + aqueous vehicle with pH 3 to 7 + non-ionic surfactant in one of the stated categories that is characterized as stabilizing/crystallization preventing + presence of optional organic solvent not exceeding 5 wt% (including the possibility of “no solvent” depending on dependent claims).
How do the dependent claims narrow the surfactants and vehicle?
Claim 2: narrows to enumerated surfactants and gives a specific SYNPERONIC parameter set
Non-ionic surfactant is selected from:
- (a) polyoxyethylene (4) monolauryl ether
- (b) polyoxyethylene (25) glyceryltrioleate
- (c) SYNPERONIC PE/L44 defined as:
- a liquid ethylene oxide/propylene oxide block copolymer
- 40% ethylene oxide / 60% propylene oxide
- molecular weight 2,000–3,000
Claim 2 is a narrower capture: it covers only compositions that use the specific surfactant(s) in the recited forms, including the defined grade of the block copolymer.
Claim 3: allows another additional non-ionic surfactant class
A composition according to claim 1 comprising a further non-ionic surfactant chosen from:
- polyoxyethylene glycerin fatty acid monoesters
This expands coverage within Claim 1’s vehicle architecture by permitting an additional non-ionic surfactant class, but only if the base Claim 1 elements remain satisfied.
Claim 4: selects a specific monoester
Polyoxyethylene glycerin fatty acid monoester is:
- polyoxyethylene (15) glycerin monolaurate
This is a further narrowing example of Claim 3.
Claim 5: limits organic solvent presence to essentially none or trace
0–0.1 wt% of the organic solvent is present.
This sharply narrows the “up to 5 wt%” concept of Claim 1 into a “near-zero” embodiment.
Claim 6: identifies the solvent chemical family
Organic solvent is a monohydric C1–C3 alkanol.
That is a constraint on solvent identity: e.g., methanol, ethanol, propanol (and isomers consistent with “monohydric C1–C3 alkanol” definition).
Claim 7: adds antibiotics into the composition
The composition contains an antibiotic.
This claim does not limit antibiotic identity, so it broadens by adding an ingredient category on top of Claim 1.
Claim 8: selects clindamycin
Antibiotic is:
- clindamycin or a derivative thereof
Claim 8 is the key “product profile” anchor for acne/skin indications where clindamycin is used.
What does the claim set imply about the intended formulation architecture?
The claim set is structured to protect a specific formulation strategy:
- Vehicle: aqueous, with pH 3–7
- Stabilization system: specific non-ionic surfactants that are “crystallization preventing and stabilizing agents for said retinoid”
- Optional solubilization: limited organic solvent presence (0 to 0.1 wt% in one dependent path; up to 5 wt% in Claim 1 baseline)
- Optional dermatology package: antibiotic addition, including clindamycin
Claim element map (practical “AND” requirements)
| Element |
Claim 1 |
Claim 2 |
Claim 3/4 |
Claim 5/6 |
Claim 7/8 |
| Retinoid |
Required |
Required |
Required |
Required |
Required |
| Topical skin composition |
Required |
Required |
Required |
Required |
Required |
| Aqueous vehicle |
Required |
Required |
Required |
Required |
Required |
| pH 3 to 7 |
Required |
Required |
Required |
Required |
Required |
| Non-ionic surfactant that stabilizes/crystallization prevents |
Required |
Must be enumerated (PE lauryl ether / PE glyceryltrioleate / SYNPERONIC PE/L44) |
Additional surfactant allowed |
Not affected |
Not affected |
| Organic solvent limit |
Up to 5 wt% (baseline) |
Not changed |
Not changed |
0–0.1 wt% |
Not changed |
| Organic solvent identity |
Not specified |
Not specified |
Not specified |
monohydric C1–C3 alkanol |
Not changed |
| Antibiotic |
Optional element via dependent claim |
Optional element via dependent claim |
Optional element via dependent claim |
Optional element via dependent claim |
clindamycin or derivative |
What is the infringement-relevant “scope perimeter”?
1) The claim is composition-level and formulation-specific
Protection is for a composition that includes the specified components and their constraints. That means:
- A product with a different vehicle pH window (outside 3 to 7) does not land in Claim 1.
- A product using a surfactant outside the listed families does not land in Claim 1 (even if it still stabilizes retinoids).
- A product with the same surfactant but with a different active class than “retinoid” does not land in Claim 1.
- A product with an organic solvent amount above the stated limit relevant to the claim being asserted (Claim 1 “up to 5 wt%” or Claim 5 “0–0.1 wt%”) can avoid dependent-claim coverage but may still test against Claim 1 depending on the amount used.
2) The surfactant limitation is both family-based and example-based
Claim 1 limits the surfactant to three groups. Claim 2 narrows further to explicit compounds/grades.
That creates a clear decision tree for “design-around”:
- Use a different non-ionic category, or
- Use a different pH outside 3–7, or
- Use a different active that is not within “retinoid” definition used in the patent’s interpretation.
3) Antibiotic + clindamycin only matters for the antibiotic-dependent coverage
Clindamycin is only required for Claim 8 coverage. A retinoid aqueous formulation without clindamycin may still infringe Claim 1 or Claim 2 depending on surfactant/pH/solvent/retinoid identity.
How do the claims position within a typical acne/dermatology formulation landscape?
The combination of:
- retinoid (acne/keratinization)
- aqueous vehicle
- retinoid stabilization against crystallization
- optional clindamycin
aligns with a market segment focused on acne topical products that aim for:
- water-based or gel/solution-like vehicles rather than oil-based emulsions
- better stability across shelf life by preventing recrystallization
- possible fixed-dose combinations with antibiotics
From a patent landscape perspective, this claim set targets a common technical failure mode:
- retinoid crystallization and instability in non-oily systems
So the real competitive risk area is not “all retinoid creams,” but retinoid aqueous systems that use specific non-ionic surfactants within the defined pH/solvent envelopes.
What does this mean for “freedom-to-operate” planning?
Claim coverage risk clusters
1) Aqueous retinoid products with pH 3 to 7 and surfactant chosen from the Claim 1 families
2) Products using one of the explicit surfactants in Claim 2
3) Near-solvent-free formulations (Claim 5) using C1–C3 monohydric alkanols (Claim 6)
4) Fixed combinations with clindamycin (Claim 8)
Design-around levers suggested by claim language
- pH outside 3 to 7
- surfactant outside the enumerated non-ionic families
- eliminate clindamycin for Claim 8 risk reduction
- alter solvent amount beyond the dependent-claim window where applicable
- use different retinoid scope if “retinoid” definition is narrowed by prosecution history or specification interpretation (not provided here)
This leans toward the conclusion that the most “robust” avoidance is changing the surfactant family and/or pH, not simply adjusting solvent content.
Patent landscape assessment (US 5,690,923 as the claim anchor)
Landscape boundaries you should assume for this asset
Given the claim structure, US 5,690,923 is positioned as a formulation stabilization patent. The likely surrounding patent landscape (in the category of topical retinoid aqueous formulations) typically includes:
- patents on retinoid stabilization in aqueous systems
- patents on surfactant systems for solubility and crystallization prevention
- patents on pH-optimized topical retinoid vehicles
- patents on retinoid-antibiotic combinations in acne treatment
However, without the full bibliographic and family details of US 5,690,923 (publication history, continuation chain, related patents, cited references, and claim construction notes), only the claim-grounded scope can be mapped reliably to competitive formulation strategies.
What you can take directly from the claims:
- Competitors that match the same surfactant families and pH window are in the highest risk zone.
- Competitors that build aqueous retinoid products using non-ionic surfactants in those categories need to assess whether the stabilization function is met in the accused product.
- Fixed-dose acne combination products that pair retinoids with clindamycin face additional claim exposure under the antibiotic-dependent claims.
Key Takeaways
- US 5,690,923 protects a topical retinoid composition in an aqueous vehicle with pH 3 to 7 and a specific non-ionic surfactant that acts as a crystallization preventing and retinoid stabilizing agent.
- The independent claim is constrained to non-ionic surfactants selected from polyoxyethylene mono fatty alcohol ethers, polyoxyethylene glyceryl fatty acid triesters, or ethylene oxide/propylene oxide block copolymers.
- Dependent claims add high specificity: enumerated surfactants (including polyoxyethylene (4) monolauryl ether, polyoxyethylene (25) glyceryltrioleate, and SYNPERONIC PE/L44 with 40/60 EO/PO and MW 2,000–3,000).
- Optional but commercially material scopes include near-zero organic solvent formulations and antibiotic combinations, specifically clindamycin or derivatives.
- Landscape risk concentrates on aqueous retinoid products that keep pH 3 to 7 and select surfactants from the claimed non-ionic families, with added exposure for clindamycin combinations.
FAQs
1) Is the patent limited to a specific retinoid (e.g., tretinoin vs. adapalene)?
The claims provided specify “a retinoid” generally; the scope here is retinoid-based, not limited to a single molecule in the claim text excerpt.
2) What pH range is required for Claim 1 coverage?
The aqueous vehicle pH must be between 3 and 7.
3) Do the claims allow organic solvent in the aqueous vehicle?
Yes. Claim 1 allows up to 5 wt% organic solvent. A dependent path (Claim 5) restricts it to 0–0.1 wt%, with Claim 6 identifying the solvent as monohydric C1–C3 alkanol.
4) Which surfactants are explicitly named in the narrowest dependent claim set?
Claim 2 names polyoxyethylene (4) monolauryl ether, polyoxyethylene (25) glyceryltrioleate, and SYNPERONIC PE/L44 with defined EO/PO composition and molecular weight range.
5) Does the patent cover retinoid products without clindamycin?
Yes. Clindamycin appears only in Claim 8 as part of the antibiotic-dependent coverage; a product can still potentially map to earlier claims if it matches the retinoid, pH, and surfactant constraints.
References
- United States Patent No. 5,690,923. (Claims as provided: Claims 1–8).
