Drug – bio-affecting and body treating compositions – Dentifrices
Reexamination Certificate
1999-04-08
2001-04-24
Rose, Shep K. (Department: 1614)
Drug, bio-affecting and body treating compositions
Dentifrices
C424S052000
Reexamination Certificate
active
06221340
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to zinc containing anticalculus dentifrice compositions. Specifically, the invention is directed to low pH dentifrice compositions employing one or more slightly soluble zinc compounds as the active agent. Even more specifically, the dentifrice compositions according to the present invention significantly enhance the bioavailability of zinc.
2. Description of Related Art
Zinc compositions have been added to dentifrice compositions for controlling calculus. See for example, U.S. Pat. No. 4,100,269 to Pader.
PCT Application WO 96/03109 to Warner-Lambert Company teaches an antiseptic, anticaries dentifrice having a pH of about 3.0 to about 5.5. Acidifiers, including phosphoric acid, acidic phosphate salts, benzoic acid and food grade acids, such as citric acid, acidify the dentifrice. The dentifrice may also be buffered by salts of the acids such as citric acid-sodium citrate, phosphoric acid-sodium phosphate, sodium monobasic phosphate-sodium dibasic phosphate, acetic acid-sodium acetate, and benzoic acid and benzoate.
U.S. Pat. Nos. 4,545,979 and 4,550,018 to Ambike et al. teach a dental hygiene composition in an acidic pH range of from 3.0 to 5.0, pH buffers, fluoride, thymol, eucalyptol, methyl salicylate, peppermint and spearmint oil flavors, and 0.1 to 2.0 percent by weight of one or more highly pure alkali metal salts of dodecyl sulphate having less than 5% non-dodecyl alkyl sulphate salts.
Canadian Patent No. 834131 to Tisserand teaches a dentifrice preparation that has an acidic pH of about 3.8 to 5.8, optimally a pH of 4.0 to 5.5, and most preferably a pH of 4.0 to 4.8; fluoride; and contains flavor oils such as menthol, methyl salicylate or thyme oil and other flavors such that the composition is substantially free of hydrocarbon terpenes. According to Tisserand when essential oils which are not free of terpenes are employed in a fluoride dentifrice which has a pH in the range of about 3.8 to 5.8 the flavor develops a pronounced rancid and sour taste in a period of less than 3 months.
While the prior art discloses low pH toothpaste and other dentifrice compositions that contain zinc, there is a need for dentifrice compositions that deliver enhanced bioavailable zinc so that the effective zinc content can be lowered. It is believed that the zinc compounds tend to be astringent. Therefore, reducing the zinc content in the product can improve the consumer acceptability of the product.
SUMMARY OF THE INVENTION
The present invention is directed to dentifrice compositions including one or more slightly soluble zinc compounds. The term slightly soluble means that the zinc compound is not more than about 0.5% w/w soluble in water. The dentifrice compositions according to the present invention also include a buffer system; and an oral vehicle, wherein the dentifrice composition has a pH from about 3.0 to about 5.5, the zinc compound is in an amount sufficient to provide at least about 2000 ppm of zinc ion and the amount of zinc ion that is bio-available is at least about 1000 ppm.
The dentifrice compositions according to the present invention contain zinc ions and a buffering agent that produces a significantly and unexpectedly enhanced bioavailablity of zinc.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The dentifrice compositions according to the present invention include a zinc source. Zinc in known to help prevent tartar in the oral cavity. The zinc compounds that can be used in the present invention include
Zinc Bacitracin
Zinc Oxide
Zinc Citrate
Zinc Peroxide
Zinc Tribromosalicylanilide
Zinc Phosphate
Zinc Carbonate
Zinc Pyrophosphate
Zinc Fluoride
Zinc Silicate
Zinc Formate
Zinc Stearate
Zinc Lactate
Zinc Tannate
Zinc Oleate
Zinc Oxalate
Zinc Chloride
Preferred salts are zinc citrate, zinc oxide, zinc pyrophosphate, and zinc silicate. The most preferred salt is zinc citrate.
The zinc salt is added to the composition in an amount sufficient to provide zinc ions in an amount from about 0.01 to about 1.0% w/w of the composition. Preferably the amount of zinc salt added to the composition is sufficient to provide zinc ions in an amount from about 0.02 to about 0.7% w/w of the composition. More preferably, the amount of zinc salt added to the composition is sufficient to provide zinc ions in an amount from about 0.05 to about 0.5% w/w of the composition. Even more preferably, the amount of zinc salt added to the composition is sufficient to provide zinc ions in an amount from about 0.1 to about 0.3% w/w of the composition.
The amount of zinc salt added to the compositions should be sufficient to provide the amounts of zinc ion listed above. The exact amount of zinc salt used can be readily determined to one of ordinary skill in the art and is dependent upon the salt used.
The pH for the preferred embodiment according to the present invention is from about 3.0 to about 5.5. A pH greater than about 5.5 has been found to decrease the antiseptic activity of the dentifrice composition.
The pH of the claimed dentifrice is adjusted to below 5.5 using suitable food or pharmaceutical grade acidifiers. These could include, but are not limited to, one or a combination of the following: phosphoric acid, benzoic acid, citric acid, or other tricarboxylic acids, and the like. The most preferred acidifiers in the present invention include a mixture of phosphoric acid from about 0.01% w/w to about 3.0% w/w, preferably in the range of from about 0.1% w/w to about 1.5% w/w, and most preferably in the range of from about 0.2% w/w to about 0.75% w/w; monobasic sodium phosphate from about 0.01% w/w to about 1% w/w, preferably from about 0.1% w/w to about 0.5% w/w, and most preferably from about 0.2% w/w to about 0.4% w/w; dibasic sodium phosphate from about 0.001% w/w to about 1.0% w/w, preferably from about 0.01% w/w to about 0.5% w/w, and most preferably from about 0.01% w/w to about 0.05% w/w; and benzoic acid in the range of from about 0.01% w/w to about 1.0% w/w, preferably from about 0.05% w/w to about 0.5% w/w, and most preferably from about 0.08% w/w to about 0.35% w/w. The exact amount of acidifier added will depend on the final pH and buffer capacity desired.
The pH of the products may be buffered with salts of the acids in question. Common buffer systems include phosphoric acid and sodium phosphate salts, or citric acid and sodium citrate. Suitable buffers for use in this invention include citric acid-sodium citrate, phosphoric acid-sodium phosphate, sodium monobasic phosphate, sodium dibasic phosphate, acetic acid-sodium acetate, succinic acid-sodium succinate, aconitic acid-sodium aconitate and benzoic acid-sodium benzoate in amounts up to about 1% w/w, preferably from about 0.05% w/w to about 0.75% w/w of the composition, and most preferably from about 0.1% w/w to about 0.5% w/w of the composition.
The dentifrice compositions according to the present invention contain anti-microbial agents and one or more fluoride-releasing compounds that provide anticaries activity. Dentifrice compositions of this invention also contain, but are not limited to, one or more of the following dentifrice additives: abrasives, surfactants, binders and thickeners, humectants, sweeteners, desensitizing agents, flavors, colors, and preservatives. The preceding active ingredients and additives are combined in a hydrous or anhydrous vehicle to form a solid (i.e. toothpowder), a semi-solid (i.e. paste or gel), or a liquid.
The present invention may also include an anti-microbial agent. One class of anti-microbial agent known for use in dentifrice is the non-cationic anti-microbial agent. A substantially water-insoluble anti-microbial agent has a solubility in water at 25° C. of less than 1%, preferably less than 0.5% and more preferably less than 0.1%. The anti-microbial agents employed in dentifrice compositions of this invention can be regarded as essentially non-ionic in character. However, many suitable anti-microbial compounds contain one or more phenolic hydroxy groups that may be ionisable at certain pHs. A more exact
Kohut Bruce
Parikh Rita M.
Pozzi Charles
Yu Dahshen
Federman Evan J.
Little Darryl C.
Rose Shep K.
Warner-Lambert & Company
LandOfFree
Zinc containing dentifrice compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Zinc containing dentifrice compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Zinc containing dentifrice compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2502411