Drug – bio-affecting and body treating compositions – Dentifrices – Oxygen or chlorine releasing compound containing
Reexamination Certificate
2001-05-11
2003-03-18
Rose, Shep K. (Department: 1614)
Drug, bio-affecting and body treating compositions
Dentifrices
Oxygen or chlorine releasing compound containing
C424S049000
Reexamination Certificate
active
06534043
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to peroxide containing dentifrices stabilized against decomposition.
2. The Related Art
Peroxides are widely viewed by the dental profession as an effective treatment against gum disease. Periodontal disorders are believed to arise from infectious anaerobic microorganisms which are active in the absence of oxygen. These microorganisms can be controlled or entirely eliminated by contact with peroxides which release oxygen. According to this rationale, oxygen creates an aerobic atmosphere destructive to the microorganisms.
Facile reactivity of the peroxide benefits performance but conversely results in storage stability problems. Dentifrices containing peroxides tend to decompose within a relatively short period of time. Not only is activity lost but there can be a marked breakdown in-the dentifrice's physical properties. Dentifrice viscosity is particularly adversely affected by the chemical breakdown of thickening agents. A variety of techniques have been developed to counter the problem.
U.S. Pat. No. 4,226,851 (Sompayrac) discloses oral compositions comprising hydrogen peroxide and zinc chloride wherein vitamin E is added as a stabilizing agent. U.S. Pat. No. 4,788,052 and U.S. Pat. No. 4,839,157 both to Ng et al. report aqueous hydrogen peroxide gel dentifrices stabilized with a combination of hydrophilic and hydrophobic fumed silica.
U.S. Pat. No. 5,059,417 (Williams et al.) reports on clear gel dentifrices having a criticality in their ratio of glycerol to polyoxyethylene-polyoxypropylene copolymer. Phosphoric acid is indicated to be beneficial as an acidifying agent.
Tin compounds are described in U.S. Pat. No. 5,217,710 (Williams et al.) as stabilizing fluoride induced gel decomposition.
U.S. Pat. No. 5,326,494 and U.S. Pat. No. 5,180,517, both to Woods, describe arylazo compounds, such as tartrazine, for stabilizing sodium perborate containing cleaning liquids.
U.S. Pat. No. 5,846,570 (Barrow et al.) discloses the use of dyes such as FD&C Blue 1 and FD&C Green 3 for stabilization of hydrogen peroxide containing dentifrice gels.
Yet even with the many advances in the field, there remains a need to discover improved systems. Consequently, systems have been sought for use in oral compositions that impart to the consumer satisfactory taste, contribute no disruptive influence upon rheology, and maintain active peroxide levels even under stressing temperature conditions.
Accordingly, it is an object of the present invention to provide a peroxide containing oral composition that maintains peroxide stability even at elevated temperatures over extended periods of time.
Another object of the present invention is to provide a peroxide containing oral composition that maintains viscosity even after extended storage.
These and other objects of the present invention will become more readily apparent upon consideration of the summary, detailed descriptions and examples which follow.
SUMMARY OF THE INVENTION
An oral composition is provided which includes:
(i) from about 0.001 to about 20% by weight of a peroxide;
(ii) from about 0.5 to about 20% by weight of potassium nitrate;
(iii) from about 0.00001 to about 1% by weight of a triphenyl methane dye; and
(iv) a pharmaceutically acceptable carrier.
DETAILED DESCRIPTION OF THE INVENTION
Now it has been found that peroxides in oral compositions can be stabilized with a combination of potassium nitrate and triphenyl methane dyes, particularly with FD&C Blue 1 or FD&C Green 3.
Potassium nitrate is a well-known dental ingredient. Commonly it is utilized as a tooth desensitizing agent. U.S. Pat. No. 3,863,006 and U.S. Pat. No. 4,400,373 to Hodosh are the seminal patents disclosing the use of this material. It was claimed for desensitizing hypersensitive dentin and cementum as well as for reducing gingival bleeding.
While investigating the use of potassium nitrate for its traditional use, it was discovered that the substance in combination with triphenyl methane dyes could stabilize peroxides against decomposition. Thus, compositions of this invention will include potassium nitrate at levels ranging from about 0.5 to about 20%, preferably from about 1 to about 10%, optimally from about 3 to about 7% by weight.
Triphenyl methane dyes employed in the present invention have the structure:
wherein R is a hydrogen, hydroxyl, carboxyl or acyloxy radical. Most preferred is when R is either hydrogen representing FD&C Blue 1 or hydroxy representing FD&C Green 3. Amounts of the dye will range from about 0.00001 to about 1%, preferably from about 0.0001 to about 0.1%, optimally from about 0.001 to about 0.01% by weight.
Another essential component of the present invention is that of a peroxide. Ordinarily the peroxide will be hydrogen peroxide but it may also be selected from the group consisting of urea peroxide, calcium peroxide, sodium peroxide, sodium percarbonate, sodium perborate and C
2
-C
30
organic peroxyacids (e.g. peracetic acid) and combinations thereof. Amounts of the peroxide may range from about 0.001 to about 20%, preferably from about 0.01 to about 15%, more preferably from about 0.1 to about 10%, optimally from about 0.5 to about 8% by weight.
Chelating acids may also be present to stabilize against peroxide decomposition. Typical chelating acids include citric acid, lactic acid, malic acid, fumaric acid, tartaric acid, phosphoric acid and mixtures thereof. Most preferred is phosphoric acid. Amounts of the chelating acid may range from about 0.001 to about 5%, preferably from about 0.01 to about 2%, optimally from about 0.1 to about 1% by weight. The compositions of the present invention may either be in paste, gel or liquid form. Most preferably it is in gel form.
A further essential component of the present invention is that of a pharmaceutically acceptable carrier. The carrier may include such functional ingredients as water, humectants, abrasives, thickeners and surfactants. Total levels of these materials may range anywhere from 0.1 to 99.9%, preferably from 20 to 99% by weight.
Oral compositions of the present invention may further include bicarbonate salts in the same or in a separate composition from that of the peroxide. Most preferably, the peroxide will be in a separate composition from that of the bicarbonate. In those situations, each composition is held within a separate compartment available for simultaneous delivery and substantially equal volumes for use in the mouth.
The bicarbonate compositions may also contain a fluoride anticaries compound. Especially preferred is sodium fluoride. Bicarbonate salts will usually be present in alkali metal form, examples of which are sodium and potassium. Typically, the concentration of bicarbonate salt will range from about 0.5 to about 80%, preferably from about 1 to about 50%, optimally between about 2 and about 20% by weight of the total combined dental product. The pH of the bicarbonate composition may range from about 7.0 to about 9.5, most preferably about 8.0 to about 9.0. Typically the bicarbonate composition will include a natural or synthetic thickening agent in an amount about 0.1 to about 10%, preferably about 0.5 to about 5% by weight. Thickeners can be selected from hydroxypropyl methyl cellulose, hydroxyethyl cellulose, sodium carboxymethyl cellulose, xanthan gum, tragacanth gum, karaya gum, arabic gum, Irish moss, starch, alginates and carrageenans.
Water may be present in the compositions in amounts ranging from about 5 to about 99% by weight. When the peroxide composition is a gel, the amount of water may range from about 20 to about 55%, optimally between 35 and 45% by weight.
Humectants are usually polyols which, for example, may include glycerol, sorbitol, propylene glycol, lactitol, xylitol, polypropylene glycol, polyethylene glycol, hydrogenated corn syrup and mixtures thereof. Generally the amount of humectant will range from about 5 to about 90%, preferably from about 20 to about 70% by weight.
When the peroxide compositions are in the form of a gel, it may be desirable to ut
Ryles Christine Watson
Williams David Robert
Honig Milton L.
Rose Shep K.
Unilever Home & Personal Care USA , division of Conopco, Inc.
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