United States Patent 5,344,641 (Dentifrice With Solubilized, Retained Antibacterial Actives): Scope, Claims, and Landscape
Patent: US 5,344,641
Subject matter (from claims): An oral dentifrice composition that adheres plaque-inhibiting antibacterials to tooth and gum surfaces by combining (1) a siliceous polishing abrasive, (2) a substantially water-insoluble antibacterial agent, (3) an antibacterial-enhancing polymer/agent that has both delivery-enhancing and retention-enhancing functional groups, and (4) a solubilizer system sufficient to dissolve the antibacterial in saliva to enable soft-tissue delivery near the gum line.
What does claim scope cover in US 5,344,641?
Core claim architecture (Claim 1 is the anchor)
Claim 1 defines a dentifrice with the following quantitative and functional elements (all in an “orally acceptable vehicle”):
- Abrasive: about 5–30% by weight of a siliceous polishing agent
- Antibacterial agent: an effective antiplaque amount about 0.01–5% by weight of a substantially water insoluble, non-cationic antibacterial agent
- Antibacterial-enhancing agent: about 0.05–5% by weight of an agent that contains:
- at least one delivery-enhancing functional group that enhances delivery of the antibacterial to oral tooth and gum surfaces
- at least one organic retention-enhancing functional group that enhances attachment, adherence, or bonding of the antibacterial on tooth and gum surfaces
- Solubilizing material: about 0.5–50% by weight sufficient to dissolve the antibacterial agent in saliva and permit delivery “to soft oral tissues at or near the gum line”
This is a “system” claim: the antibacterial is insoluble in water in the formulation sense, then becomes delivered via saliva dissolution enabled by a solubilizer, while a polymeric/non-polymeric enhancer provides retention and delivery.
Dependent claims narrow and expand the “enhancer” chemistry
Claims 2–6 narrow the antibacterial class; claims 7–9 set quantitative and solubilizer selection; claims 10–17 expand enhancer chemistry and define specific sub-structures.
Key dependencies:
- Claim 2: antibacterial selected from:
- halogenated diphenyl ethers
- halogenated salicylanilides
- benzoic esters
- halogenated carbanilides
- phenolic compounds
- Claim 3–4: halogenated diphenyl ether is 2,4,4’-trichloro-2’-hydroxydiphenyl ether
- Claim 5–6: phenolic compounds include phenol, thymol, eugenol, and 2,2’-methylene bis(4-chloro-6-bromophenol)
- Claim 7: antibacterial in about 0.25–5% (tightens Claim 1 minimum)
- Claim 8–9: solubilizer list includes polyols, glycol ethers, oils/waxes, esters; Claim 9: propylene glycol specifically
- Claim 10–12: enhancer is water soluble or swellable; molecular weight ~100 to 1,000,000; delivery-enhancing group can be acidic
- Claim 13: delivery-enhancing group selected from:
- carboxylic, phosphonic, phosphinic, sulfonic acids and salts
- organic retention-enhancing group defined by generic formula --(X)n--R, with:
- X = O, N, S, SO, SO2, P, PO, Si
- R = hydrophobic alkyl/alkenyl/acyl/aryl/alkaryl/aralkyl/heterocycle or inert-substituted derivatives
- n = 0 or 1+
- enhancer can be monomer or polymer classed into oligomers through crosslinked polymers
- Claims 14–16: emphasize an anionic polymer with multiple delivery/retention groups on repeating units, with at least one carbon atom per unit, and the groups bonded to the same or vicinal atoms
- Claim 17: adds a more specific, commercially aligned embodiment:
- dentifrice with siliceous polishing agent 5–30%
- triclosan ~0.01–5%
- poly(beta-styrenephosphonic acid) or poly(alpha-styrenephosphonic acid) or a copolymer of ether styrenephosphonic acid + monomer + propylene glycol sufficient to dissolve triclosan in saliva
Interpretation of the “scope lever”:
The broadest “hook” is the enhancer containing both (i) an acidic/delivery-enhancing functionality and (ii) a retention-enhancing hydrophobic/organic functional segment, plus the formulation-dependent solubilization of an otherwise insoluble antibacterial in saliva.
How broad is “antibacterial agent” coverage?
Chemical class breadth (Claims 2–6)
US 5,344,641 explicitly claims multiple antibacterial families beyond triclosan:
- Halogenated diphenyl ethers (including a specific trichloro-hydroxy derivative in Claim 4)
- Halogenated salicylanilides
- Benzoic esters
- Halogenated carbanilides
- Phenolic compounds, including thymol, eugenol, phenol, and a bis(chloro/bromophenol) structure
Quantitative breadth
- Claim 1: antibacterial 0.01–5%
- Claim 7: narrower range 0.25–5%
- Claim 17: triclosan specifically within 0.01–5%
This creates enforceable coverage across a spectrum of antibacterial loading. The claim is not limited to trace incorporation.
Solubility status constraint
The antibacterial must be:
- substantially water insoluble
- non-cationic
That combination narrows the antibacterial selection relative to quaternary ammonium antibacterials (cationic) and highly water-soluble actives.
How broad is the “antibacterial-enhancing agent” / polymer scope?
Function-first definition (Claim 1 and Claim 13)
Claim 1 does not prescribe polymer identity. It requires an enhancing agent with:
- delivery-enhancing functional group that enhances delivery to tooth and gum surfaces
- organic retention-enhancing functional group that enhances attachment/bonding to tooth and gum surfaces
Claim 13 then provides structural/legal boundaries for those functional groups:
- delivery-enhancing group: acidic groups (carboxylic/phosphonic/phosphinic/sulfonic acids and salts)
- retention-enhancing group: a generic formula containing:
- heteroatom-based linker possibilities (X includes O, N, S variants, P/PO, Si)
- R is a hydrophobic or organic substituent class
Structural flexibility (Claim 13)
- Retention group is defined at the level of a generic structural motif, with a wide menu for:
- heteroatom identity (X)
- hydrophobic R types (alkyl, alkenyl, acyl, aryl, alkaryl, aralkyl, heterocycle, inert substituted)
- n = 0 or 1+
The enhancer can be:
- monomer, oligomer, homopolymer, copolymer, ionomer, block/graft copolymer, crosslinked polymer systems.
Specific emphasis on anionic polymers (Claims 14–16)
Claims 14–16 narrow to:
- anionic polymer
- multiple delivery/retention groups in repeating units
- units have at least one carbon atom
- groups bonded to the same or vicinal atoms
Net effect:
The patent simultaneously claims a broad “functional enhancer system” (Claim 1) and narrower “anionic acidic polymer with hydrophobic retention segments” embodiments (Claims 14–16). Claim 17 tightens further to phosphonic styrene polymers and triclosan plus propylene glycol.
What is claimed about solubilization and delivery mechanism?
Solubilizing material range and role (Claim 1)
- about 0.5–50% by weight
- solubilizer must be in “amount sufficient” to:
- dissolve the antibacterial agent in saliva
- enable delivery to soft oral tissues near the gum line
This is not a “micro-particle suspension” claim. It is a formulation claim keyed to saliva dissolution.
Solubilizer selection breadth (Claims 8–9)
Claim 8 lists a broad set:
- propylene glycol
- dipropylene glycol, hexylene glycol
- methyl/ethyl cellosolve (glycol ethers)
- vegetable oil
- wax with at least 12 carbon atoms
- amyl acetate, ethyl acetate
- glycerol tristearate
- benzyl benzoate
Claim 9 pins propylene glycol as one exemplary solubilizer.
What is the practical “reading” of Claim 17?
Claim 17 is a more specific combination that tracks common antibacterial dentifrice strategies:
- abrasive: siliceous polishing agent 5–30%
- antibacterial: triclosan 0.01–5%
- enhancer: poly(beta-styrenephosphonic acid) or poly(alpha-styrenephosphonic acid) or ether styrenephosphonic acid copolymer with other inert polymerizable monomers or other polymer(s)
- solubilizer: propylene glycol in amount sufficient to dissolve triclosan in saliva
This claim is narrower than Claim 1 but has higher product-likelihood relevance.
Where does the claim language create design-around opportunities?
The risk is highest when a product uses the full “combination logic”: insoluble antibacterial + acidic/hydrophobic retention enhancer + saliva solubilization at meaningful concentrations + standard siliceous abrasive.
Design-around levers inside the claim language:
-
Switch antibacterial identity class away from claimed families
Claim 2 lists several families. If a commercial antibacterial active falls outside these lists and also fails other generic language (Claim 1’s “non-cationic” requirement still applies), the pathway depends on whether Claim 1’s “substantially water insoluble non-cationic antibacterial” is satisfied.
-
Avoid the enhancer architecture (acidic delivery + organic retention functional group)
Claim 13 tightly ties delivery-enhancing group to acidic types and defines retention-enhancing group via formula. A different non-acid delivery functionality plus non-matching retention motif can remove compliance with these elements.
-
Eliminate saliva dissolution requirement (or change the solubilizer’s role)
Claim 1 requires a solubilizing material at 0.5–50% sufficient to dissolve the antibacterial in saliva. Changing formulation to prevent saliva dissolution or using a different delivery system could reduce direct overlap.
-
Adjust solubilizer range outside Claim 1
If the solubilizer is outside 0.5–50% or insufficient for “dissolve in saliva,” direct scope narrows. Formulation still could infringe under broader “amount sufficient” interpretations, but the explicit range gives leverage.
-
Change abrasive system away from siliceous polishing agents
Claim 1 requires “about 5–30% by weight of a siliceous polishing agent.” Products using non-siliceous abrasives, or silicas outside this range, can fall outside.
-
Avoid anionic polymer enhancer structure
Claims 14–16 emphasize anionic polymers with multiple repeating units containing delivery/retention groups. Claim 1 does not require anionic character, but Claim 13 does require specific acidic delivery groups.
Patent landscape: what else matters for freedom-to-operate
How US 5,344,641 will be positioned in a landscape
Given the claim set, the landscape analysis typically clusters around three overlapping technical “themes”:
- Antibacterial dentifrices using insoluble actives + solubilizing vehicles + plaque inhibition
- Retention and delivery-enhancing polymers with acidic delivery functionalities
- Triclosan dentifrice systems, especially those using phosphonic/acids-containing polymer enhancers and glycols like propylene glycol
Most likely citation/overlap categories
Because the claim emphasizes:
- triclosan (Claim 17),
- styrene phosphonic acid polymers (Claim 17),
- delivery/retention functional groups (Claim 13),
- adhesion/bonding to oral surfaces and saliva dissolution (Claim 1),
US 5,344,641 sits at the intersection of:
- earlier triclosan dentifrice compositions (actives and vehicles),
- polymeric retention/delivery agents (acidic functional groups + hydrophobic retention),
- combination compositions that pair insoluble antibacterial agents with saliva-solubilizing systems.
What to track in upstream and downstream filings
For enforcement and clearance, the landscape must map:
- Whether later patents claim triclosan + phosphonic/acids-containing polymer retention systems
- Whether later patents claim other non-cationic insoluble antibacterial classes in the same enhancer/solubilizer system
- Whether later patents use alternative retention chemistries (non-acid delivery groups or retention motifs not matching Claim 13)
- Whether later patents shift away from siliceous polishing abrasive or alter abrasive fraction
Key point for investors/R&D: infringement risk rises when later products reproduce the same “element bundle” rather than just using triclosan or just using an acid-functional polymer.
Scope summary matrix (claim elements vs enforceability levers)
| Element |
Claim requirement |
Scope breadth |
Enforcement sensitivity |
| Dentifrice base |
orally acceptable vehicle + siliceous polishing 5–30% |
Medium (specific abrasive class and range) |
High if abrasive differs |
| Antibacterial active |
substantially water insoluble, non-cationic; antiplaque 0.01–5% |
Medium to high (broad functional but constrained by “non-cationic” and “substantially insoluble”) |
Medium-high depending on active selection |
| Antibacterial enhancer |
0.05–5%; has delivery-enhancing + retention-enhancing functional groups |
High (Claim 1 broad); medium (Claim 13 chemical boundaries) |
Highest if polymer matches acid + retention motif |
| Solubilizer |
0.5–50% sufficient to dissolve in saliva for gum-line delivery |
Medium (wide list, but explicit function + range) |
High if solubilization is engineered away |
| Specific subclass |
triclosan + styrenephosphonic polymers + propylene glycol |
Low to medium |
Product-specific |
Key Takeaways
- US 5,344,641 claims a dentifrice as a four-part system: siliceous abrasive (5–30%) + insoluble non-cationic antibacterial (0.01–5%) + acidic delivery/hydrophobic retention antibacterial enhancer (0.05–5%) + saliva-dissolving solubilizer (0.5–50%).
- The broadest coverage is Claim 1’s functional enhancer system and the saliva dissolution delivery concept; Claim 13 adds chemical constraints that anchor the enhancer’s acidic delivery groups and retention-group motif.
- Claim 17 is the highest product-likelihood embodiment: triclosan (0.01–5%) with poly(alpha-/beta-styrenephosphonic acids) or related styrenephosphonic copolymers plus propylene glycol.
- Landscape focus should target later filings that replicate the same element bundle, especially combinations of triclosan (or other insoluble non-cationic antibacterials) with phosphonic/acids-containing retention polymers and glycol solubilization.
FAQs
1) Is triclosan required to infringe US 5,344,641?
No. Triclosan is explicitly claimed in Claim 17, but Claim 1 covers other substantially water-insoluble non-cationic antibacterial agents. Claims 2–6 further enumerate antibacterial classes.
2) What polymer feature is central to the patent’s enhancer scope?
The enhancer must contain (a) a delivery-enhancing functional group (in Claim 13, selected from carboxylic/phosphonic/phosphinic/sulfonic acids and salts) and (b) an organic retention-enhancing functional group defined by the generic formula --(X)n--R with specified X and R selections.
3) How does the patent treat antibacterial solubility?
The antibacterial is “substantially water insoluble” in the dentifrice context, but the formulation includes a solubilizing material (0.5–50%) sufficient to dissolve in saliva, enabling delivery near the gum line.
4) Do the claims require a siliceous abrasive?
Yes for Claim 1: about 5–30% by weight of a siliceous polishing agent. That limitation narrows products that use different abrasive families or different loading.
5) What is the most actionable claim bottleneck for design-around?
The strongest bottlenecks are aligning with all three formulation logic components at once: acidic delivery + organic retention enhancer plus saliva-dissolving solubilizer plus the specified insoluble non-cationic antibacterial in a dentifrice with the required siliceous polishing range.
References (APA)
[1] United States Patent and Trademark Office. (1994). Oral composition dentifrice with antibacterial agent retention and delivery system (US 5,344,641). USPTO.
