Toothpaste products

Whilst the use of enamel and dentine as test substrates is widespread, they are complex materials to work with due to the natural variability both within and between specimens. A number of authors have examined alternative materials, which have similar mechanical properties to enamel and dentine, to use as test substrates. Acrylic [19, 20] and synthetic hydroxyapatite [21] have been proposed as suitable materials for abrasion testing, where mechanical effects dominate. These materials have several advantages since they are available as relatively large, smooth samples and exhibit better intra- and inter-sample reproducibility than their natural counterparts. This may, therefore, give better discrimination between test products for formulation development. However, the use of natural enamel and dentine is preferred, particularly for studies that aim to understand interactions between toothpaste products and tooth hard tissues. Other methods for assessing toothpaste abrasivity to hard tissues include gravimetry [22], scanning electron microscopy [23] and laser reflection [24]. 

The enamel/dentine in situ method was used in a study reported by Pickles et al. [54] to assess the abrasion caused by brushing with one of five different toothpastes covering a wide range of RDA and REA values. The results showed that for the conventional toothpaste products, the wear on both enamel and dentine was generally not significantly different, despite the fact that the RDA values differed by more than a factor of two. The results also showed that the wear rates for enamel and dentine were reduced as the study progressed, which is consistent with the observations of Lambrechts et al. [35]. 

Toothpaste production is the second largest application of sorbitol, accounting for 50,000 mto a year in Western Europe alone. In the past, toothpaste formulations were glycerine-based but almost every producer went through a reformulation process to use sorbitol when the latter became available on an industrial scale. 

Tripoli. TripoH [1317-95-9] is a fine grained, porous, decomposed siHceous rock produced mainly in Arkansas, Illinois, and Oklahoma. It is widely used for polishing and buffing metals, lacquer finishing, and plated products. Since tripoH particles are rounded, not sharp, it has a mild abrasive action particularly suited for polishing. TripoH is also used in toothpastes, in jewelry polishing, and as filler in paints, plastics, and mbber. Rottenstone and amorphous siHca are similar to tripoH and find the same uses. In 1987 the abrasive use of tripoH in the United States totaled 26.6 million tons and was valued at about 3.1 million however, the portion used as a filler totaled 71.1 million tons and had a value of almost 10 million (4). 

Glycerol is used in nearly every industry. The largest single use is in dmgs and oral care products including toothpaste, mouthwash, and oral rinses (Table 3). Its use in tobacco processing and urethane foams remains at a fairly even consumption level. Use in foods and cosmetics is growing. 

Wintergreen Oil. Water distillation of the leaves of Gaultheriaprocumbens L. yields an oil which consists of essentially one chemical constituent, methyl saUcylate. Because of this, the oil has been almost totally replaced by the synthetic chemical. Natural oil of wintergreen [68917-75-9] is a pale yellow to pinkish colored mobile Hquid of intensely sweet-aromatic odor and flavor. The oil or its synthetic replacement find extensive use in pharmaceutical preparations, candy, toothpaste, industrial products, and in rootbeer flavor. In perfumery, it is used in fougnre or forest-type fragrances. 

White Hydroxide. Tlie soda sinter process appHed to bauxite or bauxite residue produces a hydroxide that is completely free from organic coloring matter and is very wliite. A value of more than 95% is obtained on the GE brightness scale relative to Ti02 as followed in the paper (qv) industry. Tliis compares to about 70% on the same scale for the nomial Bayer product. Tlie wliite hydroxide is preferred in the paper, toothpaste, and artificial marble industries. 

Oral Cleansing Products. Toothpastes and mouthwashes are considered cosmetic oral cleansers as long as claims about them are restricted to cleaning or deodorization. Because deodorization may depend on reduction of microbiota in the mouth, several antimicrobial agents, either quaternaries, such as benzethonium chloride [121 -54-0] or phenoHcs, such as triclosan [3380-35-5] are permitted. Products that include anticaries or antigingivitis agents or claim to provide such treatment are considered dmgs. 

Several agents deUvered via toothpaste inhibit the accumulation of dental calculus. Pyrophosphate salts, with or without a methoxyethylene—maleic acid copolymer, and zinc salts have given positive results in clinical trials (5). Pyrophosphates were added as potassium or sodium pyrophosphate or mixtures at a level of about 2—6%. The zinc salt was zinc citrate [546-46-3] (0.5—2.0%) or zinc chloride [7646-85-7] (2.0%). The products all contained fluoride in addition to the calculus inhibitor. The anticaries activity of the fluoride was not compromised (6). 

The strongly re search-oriented dentifrice market is dominated by a few primary companies. The industry funds efforts to develop products with superior cosmetic and therapeutic performance. The four principal manufacturers of toothpaste worldwide are Procter Gamble, Unilever, Colgate-Palmohve, and Beecham. Numerous smaller companies and private-label houses also exist. 

Though dental afflictions constitute a very significant disease entity, these have received relatively little attention from medicinal chemists. (The fluoride toothpastes may form an important exception.) This therapeutic target Is, however, sufficiently Important to be the focus of at least some research. A highly functionalized piperazine derivative that has come out of such work shows prophylactic activity against dental caries. Condensation of the enol ether 1 of thiourea with ji-pentylisocyanate gives the addition product 1J. Reaction of this with diamine 78, derived from piperazine, leads to substitution of the methylthio moiety by the primary amine, in all likelihood by an addition-elimination sequence. There is thus obtained ipexidine (79). ... 

Xanthan has some unique properties and high activity at low concentrations and is commercially the most important exopolysaccharide. Food products account for approximately 60% of xanthan use, 15% is accounted for by toothpaste, textiles and crop protection products, 10% in the oil industry and the remainder in miscellaneous industrial/consumer applications. 

The resolution of DL-menthol is important industrially. L-Menthol has a mint taste and gives a cooling sensation. It finds use in a number of important products including toothpaste and confectionary. D-Menthol does not have the same taste nor the same cooling properties. DL-menthol can be produced relatively simply using a variety of chemical routes. 

Zinc oxide is a white powder that makes a very opaque paste when mixed with water or oils. It is used as a sunblock and as a colorant in toothpastes and cosmetics. Zinc oxide is used in many of the same products as titanium dioxide. 

Glycerin is about three-quarters as sweet as sugar, so it can reduce the need for sugar in products that require it for other reasons. In toothpaste it sweetens while keeping the paste from drying out when the cap is left off. 

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