MXPA00006884A - Oral care compositions - Google Patents

Abstract

An oral care composition is provided in the form of a transparent gel, comprising an abrasive silica, a thickening silica, a polyol-humectant-containing liquid vehicle, and a low level of sodium bicarbonate. Despite the presence of the bicarbonate, the product is a transparent gel or white paste, and provides for a teeth-whitening effect, as well as a reduction of oral malodour, and neutralizes the acid, formed in the oral cavity by microbial decomposition of sugar. The composition may be coloured, and different compositions with different colours, e.g. a blue or a white one, may be dispensed from a single or a multicompartment container.

Description

COMPOSITIONS FOR MOUTH CARE DESCRIPTION OF THE INVENTION The present invention relates to oral care compositions in the form of a gel. More particularly, it relates to oral care compositions in the form of transparent gel which contains a source of metal bicarbonate at 1 flax. Compounds for oral care in gel form are well known in the art. They usually comprise an abrasive silica and a thickener silica in a convenient liquid carrier comprising a polyol humectant such as sorbitol, glycerol, lactitol, xylitol etc., with other optional ingredients. By a judicious selection of the types of silica abrasive and silica thickener, particularly, in relation to the indexes of the release of these materials, transparent gels can be obtained, and such compositions for oral care have already found their way into the market. However, when optional ingredients are included, care must be taken not to risk the transparency of the gels.

Lately, oral care compositions containing a source of alkali metal bicarbonate, for example sodium bicarbonate, have been developed and marketed. This material can function as a light abrasive in the composition for oral care, as well as an agent for neutralizing the acids, formed in the oral cavity by the microbial decomposition of the sugar. However, the fact that a source of alkali metal bicarbonate in a gel care composition can jeopardize the transparency of the gel. Currently, there is a demand for oral care compositions in the form of transparent gel, which provide a whitening effect on the teeth as well as a reduction in oral malodor and an improved effect - e ~ cleaning and acid removal. It has now been found that the inclusion of a low level of a source of alkali metal bicarbonate in a gel-based oral care composition which comprises a thickener silica and a particular abrasive silica provides a composition for care Oral gel, which is transparent, provides a whitening effect on teeth, reduces odor and neutralizes acids, formed in the oral cavity by the microbial decomposition of sugar to a significant degree. It is surprising that the inclusion of a low level of the alkaline bicarbonate does not jeopardize the transparency of the gel. The alkali metal bicarbonate source used in the present invention may be sodium and potassium bicarbonate or mixtures thereof, with sodium bicarbonate being the preferred material. The amount of the alkali metal bicarbonate source, included in the composition of the invention, ranges from 0.5 to 5% by weight of the composition, preferably from 0.75 to 3% by weight, and preferably from 1 to 2. % in weigh. The thickener silica, used in the present invention, can be any thickening thickener, known in the art, such as Sident 22S, Sorbosil TC15, Tfxosil 43 and Hi Sil DT 267M. The thickener silica is generally used in an amount of 3-15%, preferably 5-10% by weight of the composition.

The particular abrasive silica used in the present invention is a silica with a low refractive index. It can be used as the sole abrasive Li c, or together with a low level of other abrasive silicas, for example those according to EP 23607Q. The silicas of low refractive indexes, used as abrasives in the present invention are preferably silicas with an apparent refractive index (RI) in the range of 1.41-1.47, preferably 1435-1.445, which preferably has a particle size. a weight average of between 5 and 15 μm, a BET (nitrogen) surface areas of between 10 and 100 m2 / g and an oil absorption of approximately 70-150 cm3 / 100 g, but abrasive silicas with an "index" can also be used of less apparent refraction Typical examples of suitable abrasive silicas of low refractive index (for example having an RI of between L-435 and 1445) are the Tixosil 63 and 73 ex Rhone Poulec; Sid in t 10 ex Degussa; Zeodent 113 ex Zeofinn; Zeodent 124 former Huber, Sorbosil AC 77 former Crosfield Ciiemicals (which has R.I. of approximately 1,440). Additional examples may be found in E P-A-0, 549, 287 (COLGATE) and in WO 94/10087, EP 535,943, EP 666,832, (Crosfield) which are incorporated herein by reference. The amount of these silicas in the composition generally ranges from 5-60% by weight, usually from 5-20% by weight. The humectants used in the compositions of the invention are the conventional polyol humectants such as sorbitol, glycerol, mannitol, lactitol, xylitol, and mixtures thereof, usually used in an amount of 30-85% by weight, preferably 50- 75% in weight. Sorbitol is the preferred humectant. The liquid phase of the composition of the present invention must be formulated in such a way that its refractive index closely matches the refractive index of the silicas as discussed above. The liquid phase usually comprises water and a polyol humectant, the latter usually being sorbitol or glycerol. The water has a R.I. of 1333, sorbitol (70% aqueous solution) has a R.I. of 1457 and glycerin and R.I. of 1,473. Other humectants such as propi 1 engl i co 1, po 1 ip r op i 1 engl i c sl, and po i i i i egl i col may also be present. The refractive index of the liquid phase can be calculated from the respective indexes of the content of the constituent ingredients. The compositions of the invention may additionally contain optional ingredients, as long as the clarity of the dentifrices is not deteriorated and the R.I. of the liquid phase is about R.I of the abrasive silica of low refractive index. The compositions of the present invention may also contain optional ingredients, well-known in the art, in verc-tional amounts. Examples of such optional ingredients are connectors such as sodium hydroxide and sodium carbonate, and xanthan gum, regulatory salts such as trisodium orthophosphate, solid-state agents such as potassium hydroxide. ie ti 1 engl i col is, agents t s ioa ct i vo s such as anionic, nonionic and amphoteric surfactants, for example 1 auriflute sodium, sulfur, sweetening agents, coloring agents , anticaries agents such as sodium fluoride and / or mono-flower ofos sodium, preservatives, etc. Additional optional ingredients are antibacterial agents, antiplaque agents such as zinc citrate, pyrophosphate tin, "agents. plant extracts, such as ziziphns juazeiro, bleaching agents such as compounds, s ensessing agents such as potassium salts, plate regulators such as glycerol phosphate calcium and urea, etc. Minor amounts of other additional abrasives may also be included, so long as the transparency of the gel does not compromise with that, such as dicalcium phosphates, calcium pyrophosphates, calcium carbonates and aluminas. The compositions of the invention can be prepared as single compositions, or they can be prepared as multiple compositions, either for delivery from a single container or from a multi-component container. A preferred form is a dual composition, each composition has a different color, the dual composition is supplied from a single container. The compositions of the invention may also contain colored particles suspended therein, for example colored silica agglomerates or other colored particles to impart a "mottled" appearance to the dentifrices. The dentifrices may also contain strips of a colored paste, for p rx > Provide a clear gel-type toothpaste with colored strips or a separate colored phase. The present invention will be illustrated by way of example. - E j emple 1 Clarity studies will be carried out with the following formulation, in which the level of sodium bicarbonate was varied (1%, 5% and 10%). Samples of the formulation were placed in a cuvette, and the cuvette was placed on an illuminated platform, and a transparency scale varying from -12 to +13 behind the cuvette was placed. The scale slid behind the bucket and a reading was taken, when the characters on the scale became clearly readable. The formulation used is as follows: ~~ The following results were obtained: X = 1% scale reading from 0 to +4 X = 5% scale reading from -9 to -12 X = 10% scale reading from -9 to -12 Were tested. formulations based on Examples of the present invention, but with 1% additional titanium dioxide for color stability after storage for one month at 10, 28 and 40 ° C. The color was measured by a standard Color Stability Index Method, and the color indexes had the following meaning. 0: - No change of color was observed 1: - A change of color was observed very 1 ige ro- after a careful analysis so 2: - A slight change of color was observed where a strong link with the color could be noticed or ri gi na 1 3: - Moderate color change where much of the original color was lost 4: - Major color change where most of the original color was lost 5: - Severe color change without link with the original obtained the following results: x = 1% color index without mist ri 11 ami in all of a month of storage at 10, 28 and 40 ° C x = 10% color index:, yellowing after one month of storage at 28 ° C and 40 ° C The following are double composition formulations according to the invention, to be supplied from a simple container, comprising 50% by weight of the white formulation and 50% by weight of 1. aazu 1. _-_ _- _ -

Claims (4)

1. Composition for mouth care in the form of a transparent gel, comprising a syringe, and an abrasive silica with a refractive index of 1.47 or less in a liquid carrier containing polyol humectant, characterized in that the gel additionally contains 0.5 to 5% by weight of a source of alkali metal bicarbonate.

2. Composition according to the rei indication 1, characterized in that the source of alkaline metal bicarbonate is sodium b-cabsinate. -

3. Composition according to claims 1 or 2, characterized in that it contains a coloring agent.

4. Buccal care product for delivery from a single container or multiple compartments characterized in that it contains at least two compositions of different color ie according to claims 1-3. RE SUMEN A mouth care composition is provided in the form of a clear gel, comprising an abrasive silica, a thickener silica, a liquid vehicle containing polyol humectant, and a low level of sodium bicarbonate. Despite the presence of bicarbonate, the product is a transparent gel or white paste, and provides a whitening effect of the teeth, as well as a reduction of oral malodor, and neutralizes the acid formed in the oral cavity by microbial decomposition of sugar. The composition can be colored, and different compositions with different colors, for example a blue or a white one, can be supplied from a single or multi-compartment container.