Oral bleaching composition

Description of the invention

The invention relates to an oral tooth cleaning composition with improved whitening effect on teeth. More particularly, the invention relates to an oral tooth cleaning composition with improved whitening effect containing a safe and effective amount of certain organic peracids.

WO 96/05802 discloses oral care compositions which impart a white color to the teeth. This activity has been achieved by incorporating certain organic peracids as whitening / whitening agents into oral care compositions, in particular peroxyamidophthalamides and cationic peroxycarboxylic acids such as N-phthalimidoperhexanoic acid and quaternary benzyl peroxy acid. It would be preferable to use peracids more effectively in a whitening / whitening agent intended for use on the teeth.

WO 96/05802 (Unilever) discloses an oral care composition containing peracids. Examples include N, N-phthaloylaminoperoxicaproic acid (PAP). There is no disclosure of the combination of PAP and hydrogen peroxide.

US 5,616,335 (Nicolle) discloses an organic peracid in a disinfectant and / or cleaning agent. Again, no combination of PAP and hydrogen peroxide is disclosed.

US 6,136,297 (Sagel) discloses a flexible ribbon (strand) for applying a whitening agent to the surface of a tooth. Specific whitening agents disclosed include peroxides, chlorites, percarbonates, peracids, and combinations thereof. There is no disclosure of a combination of PAP and hydrogen peroxide.

WO 00/59461 (Unilever) discloses a peroxide compound and a penta-serrated nitrogen-containing ligand such as FeMeN4Py. There is no disclosure of a combination of PAP and hydrogen peroxide.

The object of the invention is to provide a whitening composition more effective than that disclosed in WO 96/05802.

We have surprisingly found that the use of hydrogen peroxide in combination with a peracid produces a more effective whitening / whitening agent than the prior art disclosure of WO 96/05802.

The invention relates to an oral tooth cleaning composition comprising: a peracid which is acceptable for physical contact with the interior of the oral cavity of mammals, and the composition further comprises either hydrogen peroxide in an amount from 0.01% to 5.0% by weight, or a source thereof, which source produces hydrogen peroxide in an amount from 0.01% to 5.0% by weight of the composition, and the peracid is peroxamidophthalimide with the general formula:

<img file="PL203249B1_D0001.tif" />

wherein R represents a hydrogen atom or a C1-4 alkyl group; n is 1 to 8 and X is C = O or SO2.

Preferably, the hydrogen peroxide is in the form of carbamide peroxide.

Preferably, the peracid is present in an amount from 0.01% to 5% by weight of the composition.

Preferably the composition of the invention comprises N, N-phthaloylaminoperoxocaproic acid (PAP) as the peracid.

Also preferably the composition comprises a peracid in the form of a cyclodextrin complex. Preferably the composition according to the invention is in a form selected from the group consisting of gel bioadhesive flakes / strips, tooth enamel and toothpaste.

Of course, the peracid used must be acceptable for users and due to legal regulations. Such acceptability will be apparent to the person skilled in the art. Regulatory requirements vary depending on the legislation and the mammal being treated. Of course, higher standards apply to treating people. The term "acceptable for physical contact" must be read in the sense of the disclosure set forth herein.

The peracid used in the composition according to the invention is a peroxyamidophthalamide with the formula:

PL 203 249 B1

<img file="PL203249B1_D0002.tif" />

wherein R is hydrogen or C1-4 alkyl, n is 1 to 8, and X is C = O or SO2. The most preferred peracid is N, N-phthaloylaminoperoxicaproic acid (PAP).

Preferably, the peracid is present in the composition in an amount ranging from 0.01% to 5% by weight, more preferably from 0.05% to 4%, most preferably from 0.1% to 2% and most preferably from 0.5% to 1.5% by weight by weight of the composition.

Preferably the source of peroxide is present in an amount of from 0.05% to 4%, more preferably from 0.1 to 2% by weight of the composition.

The peroxide source is preferably hydrogen peroxide, but also other sources may be suitable for use in oral care compositions, for example, carbonide peroxide. The present invention may be used in using compositions to whiten / whiten / clean the teeth.

The invention is operated as a commercial package containing the cleaning composition of the invention together with instructions for its use.

In addition to oral administration, the composition can be used to clean dentures.

The oral compositions of the invention may also contain further ingredients customary in the art, such as:

antimicrobial agents, e.g., triclosan, chlorhexidine, copper, zinc and tin salts, such as zinc citrate, zinc sulfate, zinc glycinate, sodium zinc citrate and tin pyrophosphate, sanguinary extract, metronidazole, quaternary ammonium compounds such as cetylpyridinium chloride; biguanides such as chlorhexidine digluconate, hexetidine, octenidine, alexidine and halogenated biphenyl compounds such as 2,2'-methylene bis- (4-chloro-6-bromophenol);

anti-inflammatory agents like ibuprofen, flurbiprofen, aspirin, indomethacin, etc .;

anti-caries agents such as sodium and tin fluoride, amine fluorides, sodium monofluorophosphate, sodium trimetaphosphate and casein;

plaque buffers such as urea, calcium lactate, calcium glycerophosphate, and strontium polyacrylate;

vitamins such as vitamins A, C and E; plant extracts;

disinfectants, e.g., potassium citrate, potassium chloride, potassium tartrate, potassium hydrogen carbonate, potassium oxalate, potassium nitrate, and strontium salts;

anti-tartar agents, e.g., alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates and phosphatites etc .;

biomolecules, e.g. bacteriocins, antibodies, enzymes, etc .;

flavoring agents, e.g., peppermint and spearmint oils;

other protein materials such as collagen, keratin;

preservatives;

opacifiers;

coloring agents;

pH adjusters; sweeteners;

pharmaceutically acceptable carriers, e.g. starch, sucrose, water or water / alcohol systems etc .; surfactants such as anionic, nonionic, cationic and zwitterionic or amphoteric surfactants;

particulate abrasives such as silicas, alumina, calcium carbonates, dicalcium phosphates, calcium pyrophosphates, hydroxyapatites, trimetaphosphates, insoluble hexametaphosphates and the like, including agglomerated particulate abrasives, typically in an amount between 3 and 60% by weight of the oral care composition;

humectants such as glycerol, sorbitol, propylene glycol, xylitol, lactitol and the like;

binders and thickeners such as sodium carboxymethylcellulose, xanthan gum, acacia, etc. as well as synthetic polymers such as polyacrylates and carboxyvinyl polymers such as Carbopol®;

Polymeric compounds that can enhance the delivery of active ingredients such as antimicrobial agents may also be included. Examples of such polymers are polyvinylmethylether maleic anhydride copolymers and other similar delivery-enhancing polymers, e.g. as described in DE-A-3942643 (Colgate);

buffers and salts to buffer the pH and ionic strength of the oral care composition;

and other optional ingredients that may be included are e.g. bleaching agents like peroxy compounds e.g. potassium peroxydiphosphate, effervescent systems like sodium bicarbonate / citric acid systems, color change systems and the like.

Liposomes can also be used to improve the delivery or the stability of active ingredients.

Oral compositions may take any form conventionally in the art, e.g. toothpaste, gel, foam, bioadhesive pads / strips, aerosol, gum, lozenges, tooth enamel, mouth rinses, powder, cream etc. and may also be formulated into systems for use in two-chamber type containers.

Experimental part

The bleaching agents were assessed as follows:

(1) synthetic hydroxyapatite discs are polished and placed in sterile saliva at 37 ° C overnight to form a film;

(2) the discs are stained in the tea solution for seven days at 37 ° C;

(3) the colored discs are immersed in the whitening solution for the desired period of time;

(4) disc color change is measured using the CR-300 chromameter in the L * a * b * system.

Using the L * (initial), L * (colored), and L * (purified) values, the percent color removal is calculated. Negative values ​​indicate darkening and positive values ​​show a whitening (whitening) effect.

All compositions used were made up in 0.5 M NaHCO3. Negative values ​​indicate darkening.

Table 1 below shows the results for the use of PAP alone in a 0.5 M aqueous solution

NaHCO3 together with 0.1% H2O2.

<td></td><td>% color removal</td>

<td></td><td>15 minutes</td>

<td>0.5 M NaHCO3</td><td> -13</td>

<td>0.5 M NaHCO3 / 0.1% H2O2</td><td> -11</td>

<td>0.5 M NaHCO3 / 1% w / w PAP</td><td> 11</td>

<td>0.5 M NaHCO3 / 0.1% H2O2 / 1% w / w M PAP</td><td> 16</td>

The results presented in Table 1 show that adding hydrogen peroxide to the peracid produces a more effective whitening composition than adding PAP alone.

Table 2 shows the data for a PAP whitening experiment in which commercially available products were used in the preparation of the formulation.

<td></td><td colspan="3">% color removal</td>

<td></td><td>1 min</td><td>5 min</td><td>10 min</td>

<td>0.5 M NaHCO3 (control)</td><td> -28</td><td> -30</td><td> -31</td>

<td>Eureco ™ HCP-11 (1% PAP by weight)</td><td> -4</td><td> 32</td><td> 45</td>

<td>Eureco ™ HCL-17 (1 wt% PAP)</td><td> 4</td><td> 47</td><td> 63</td>

<td>0.1% H2O2</td><td> -30</td><td> -31</td><td> -25</td>

<td>0.1% H2O2 / Eureco ™ HCL-17 (1% w / w PAP)</td><td> 7</td><td> 60</td><td> 86</td>

PL 203 249 B1

Eureco HCP-11 is a commercially available formulation containing the PAP / cyclodextrin complex.

Eureco HCL-17 is a commercially available formulation containing an aqueous dispersion of PAP. The above-mentioned commercially available formulations are available from Ausimont; Via S. Floor, 50 / A 1-20021 Bollate, Milano, Italy.

The results presented in Table 2 above show that HCL-17 is a more active whitening agent than HCP-11 at an equal weight / weight PAP content. The presence of 0.1% H2O2 in HCL-17 gives an unexpected increase in the whitening effect.