Creams preservation

Emulsifiers, stabilizers and gelling agents (frozen food, sauces and seasonings", pastries and ice creams, preserved meat, beer and fruit juices), reconstituted food (commercially produced fruit tarts, fruit in syrup, and olives/anchovies. . . ) Microbeads of alginates for yeast encapsulation for the production of champagne and of microorganisms for the dairy industry. 

Propylene glycol is also an effective humectant, preservative, and stabilizer and is found in such diverse apphcations as semimoist pet food, bakery goods, food flavorings, salad dressings, and shave creams. Humectancy, or the capabiUty of retaining moisture in a product, is a result of the vapor—Hquid equihbria of the glycol—water system and can be estimated from tables provided by suppHers (27). 

Cysteine is used as a reductant for cold wave treatment in place of thioglycoHc acid. A/-Lauroylarginine ethyl ester [48076-74-0] is appHed as the hydrochloride as a preservative. Urocanic acid [104-98-3] hich. is derived from histidine is used in skin cream as a uv absorber (235). 

Concentration. Tea extracts are generally concentrated under vacuum to the soHds content desired for drying. Ereeze concentration has been described (99), as has reverse osmosis (qv) (100). Preserved aroma and the solubiHzed cream fraction may be added before drying. 

Perfumes, Flavors, Cosmetics, and Soap. Many naturally occurring esters in essential oils and some synthetic esters are important fragrance and flavor compounds (61,62). They are used in perfumes, flavors, cosmetics, soaps, detergents, and air fresheners. Benzyl, butyl, ethyl, methyl, and phenyl esters of benzoic acid are used as flavors, perfumes, and food preservatives. Glyceryl 4-aminobenzoate [136-44-7] and 2-ethyUiexyl 4-dimethylaminobenzoate [21245-02-3] are used in cosmetic sunscreen preparations. Alkyl esters of 4-hydroxybenzoic acid, called parabens, have been used under various names for fungus infections of the skin, and as preservatives in lotions and creams (101). Soap and cosmetic fragrances use large amounts of amyl and benzyl saHcylate. Benzyl saHcylate [118-58-1] is also used in deodorant sprays. 2-Ethylhexyl saHcylate [118-60-5] and 2-ethylhexyl 4-methoxycinnamate [5466-77-3] are used in sunscreen formulations (102). 

Here the TEWL-value measurements showed that Kujalnik peloids and magnesium pelobischofite complex salutary potentize each other in their mixtures and provide the effective preservation of acidic mantle of the skin. Besides, the pelobischofite addition to the cosmetic cream compositions results in the effective coverlet moistening. Also, the pelobischofite addition provides the decrease of the negative surfactants effect on the skin health. The TWL parameter value is less by half, the water balance of the skin is normalized and the wrinkled skin becomes smoothed out and velvety. 

Preservatives are widely employed in cosmetic preservation for lotions, creams and shampoos. Preservation is also an important aspect of formulation in emulsion paints and cutting fluids, i.e. fluids used to cool and lubricate lathe and drilling tools. 

Preservative availability may be appreciably reduced by interaction with packaging materials. Examples include the permeation of phenolic preservatives into the rubber wads and teats of multi-dose injection or eye-drop containers and by their interaction with flexible nylon tubes for creams. Quaternary ammonium preservative levels in formulations have been significantly reduced by adsorption onto the surfaces of plastic and glass containers. Volatile preservatives such as chloroform are so readily lost by the routine opening and closing of containers that their usefulness is somewhat restricted to preservation of medicines in sealed, impervious containers during storage, with quite short use lives once opened. 

HCF was especially widely used in Western countries. Until 1972, it was included as an active component in soaps, cleansing creams, shampoo, deodorants, creams, and toothpastes. HCF was used for medical purposes, to control staphyllococcus contamination, in particular in maternity hospitals and in the cosmetics industry it was also used as a preservative, etc. It was used in agricultural formulations as well [67]. Although HCF s toxicity was... 

Goger and Gokcen [19] developed a quantitative method for the determination of miconazole in cream formulations that contain benzoic acid as preservative by second order derivative spectrophotometry. The procedure was based on the linear relationship in the range 100—500 pg/mL between the drug concentration and the second-derivative amplitudes at 276 nm. Results of the recovery experiments performed on various amounts of benzoic acid and the determination of miconazole in cream confirmed the applicability of the method to complex formulations. 

Numerous CE separations have been published for synthetic colours, sweeteners and preservatives (Frazier et al., 2000a Sadecka and Polonsky, 2000 Frazier et al., 2000b). A rapid CZE separation with diode array detection for six common synthetic food dyes in beverages, jellies and symps was described by Perez-Urquiza and Beltran (2000). Kuo et al. (1998) separated eight colours within 10 minutes using a pH 9.5 borax-NaOH buffer containing 5 mM /3-cyclodextrin. This latter method was suitable for separation of synthetic food colours in ice-cream bars and fmit soda drinks with very limited sample preparation. However the procedure was not validated for quantitative analysis. A review of natural colours and pigments analysis was made by Watanabe and Terabe (2000). Da Costa et al. (2000) reviewed the analysis of anthocyanin colours by CE and HPLC but concluded that the latter technique is more robust and applicable to complex sample types. Caramel type IV in soft drinks was identified and quantified by CE (Royle et al., 1998). 

Ointments and Creams Ointments are applied to the skin for topical treatment or to be absorbed into the blood system for delivery to target areas. They are semisofid preparations obtained by mixing the API with selected ointment bases depending on intended use. These bases include petrolatum, paraffin, mineral oil, lanolin, and glycols. Preservatives are often added to ensure the ointments will maintain the recommended shelf life. 

The generally low lipid content and the poor viscosity of lipid nanodispersions make these preparations, as they are, less suitable for dermal drug application. The handling of the preparation by the patient is improved by SLN incorporation into ointments, creams, and gels. Alternatively, ready-to-use preparations may be obtained by one-step production, increasing the lipid phase to at least 30%. However, increasing the lipid frequently results in an unwanted increase in particle size. Surprisingly, it has been found that very concentrated (30 to 40%) semisolid cetyl palmitate formulations preserve the colloidal particle size [10]. 

In Figure 3, the active steroid (triamcinolone acetonide) and preservative (benzyl alcohol) are determined from a steroid cream. The higher molecular weight components of the cream base are well separated from the analytes. The ability to elute all the components of a cream or ointment in a SMGPC analysis gives an important sample preparation advantage over competing separation techniques. 

Cosmetics are preparations (except so and detergents) for the preservation and beauty of the body. In the rich countries domesticated animals also have their cosmetics, such as creams based on a>3-polyunsaturated fetty acids, for strengthening and repair of feet and noses of hounds and pointers. 

Different household liquids can be tested such as ammonia, vinegar, tap water, lemon juice, and Sprite. Items such as orange juice that possess a characteristic color should be diluted and then tested. Diluted solutions of solids like dishwasher soap, cream of tartar, and baking soda can also be made. The indicator can be frozen or mixed with alcohol to preserve for later use. 

Percutaneous penetration of 7V-nitrosodiethanolamine was measured using cryo-preserved human trunk skin and three vehicle formulations (isopropyl myristate, sunscreen cream or a 10% shampoo) containing 7V-nitroso[ C]diethanolamine. The absorption rate of a low dermal dose (10 ixg/cm ) of 7V-nitrosodiethanolamine was a linear function of the concentration (0.06, 0.2 or 0.6 Xg/ xL) applied to the skin. The peak rates for the isopropyl m uistate and shampoo vehicles were seen within five hours and for the sunscreen somewhat later. Total 48-h absorption ranged from 35 to 65% of the dose and was formulation-dependent (isopropyl m uistate > shampoo > sunscreen). A total absorption of 4-6 x JcaE was estimated to equate to an applied N-nitrosodiethanolamine dose of 10 x%lcaE. When applied as a large infinite dose (0.5 mg/cm ), total 7V-nitrosodiethanolamine absorption (4-35% of the applied dose) followed a different rank order (shampoo > isopropyl m uistate > sunscreen), probably due to the barrier-damaging properties of the vehicles. The permeability coefficient for isopropyl myristate was 3.5 X 10 cm/h (Franz etal., 1993). 

Oral liquid and semisolid formulations containing water as part of the vehicle may be prone to microbial spoilage in the absence of a preservative. In the case of pharmaceutical creams, these are usually oil-in-water emulsions stabilized using a surfactant. Phenolic preservatives, e.g., parabens esters, are inactivated in the presence of nonionic surfactants, and this detrimental interaction can have serious consequences for preservation of the product (20). 

Indication Active ingredient Cream trade name Structure-forming excipients Preservative... 

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