Compositions useful for tooth whitening
View Patent ↗The present invention provides tooth whitening compositions in the form of a liquid crystal or a microemulsion that includes a tooth whitening agent in an amount effective to whiten teeth, a hydrophilic phase including water, a hydrophobic phase including at least one oil, at least one anionic, nonionic, amphoteric or zwitterionic surfactant, and a water soluble co-solvent having a Hildebrand solubility parameter above 12 (cal/cm 3 ) 1/2 , as well as methods for whitening teeth including applying the liquid crystal or microemulsion composition to the teeth for a period of time and under conditions effective to whiten the teeth.
1. A method for whitening teeth comprising applying a composition to the teeth for a period of time and under conditions effective to whiten the teeth, the composition comprising,
a whitening agent comprising a peroxide in an amount of from about 1% to about 35% by weight of the composition,
a hydrophilic phase comprising water in an amount of from 1% to about 80% by weight of the composition,
a hydrophobic phase comprising an oil in an amount of from 1% to less than 50% by of the composition, said oil being selected from the group consisting of olive oil, coconut oil, linseed oil, mineral oil, clove oil, isopropyl myristate and isopropyl palmitate,
a surfactant selected from the group consisting of anionic, nonionic, amphoteric and zwitterionic surfactants; and
a water-soluble co-solvent having a Hildebrand solubility parameter above 12 (cal/cm 3 ) 1/2 ,
wherein the composition is in a form selected from the group consisting of a liquid crystal and a microemulsion, wherein the composition is free of a thickener selected from the group consisting of a synthetic polymer, a natural gum and a synthetic gum, and wherein and the hydrophilic phase is in predominant weight proportion relative to the hydrophobic phase in the composition.
2. The method according to claim 1 wherein the oil has a Hildebrand solubility parameter value ranging from about 5 to about 12 (cal/cm 3 ) 1/2 .
3. The method according to claim 1 wherein the co-solvent is selected from the group consisting of monohydric alcohols, polyhydric alcohols, sugars and polyols.
4. The method according to claim 1 wherein the co-solvent is selected from the group consisting of ethanol, propanol, propylene glycol, butylene glycol, ethylene glycol, glycerine, glucose, fructose, mannose, mannitol, malitol, lactitol and inositol.
5. The method of claim 1 wherein the period of time ranges from about 2 minutes to about 24 hours.
6. The method of claim 5 comprising repeated application of the composition at predetermined time intervals.
7. The method of claim 1 wherein the weight ratio of the hydrophilic phase to the hydrophobic phase ranges from about 1.5:1 to about 10:1.
8. The method of claim 2 wherein the weight ratio of the hydrophilic phase to the hydrophobic phase ranges from about 1.5:1 to about 10:1.