Methylparaben and propylparaben

Melt the stearyl alcohol and white petrolatum (steam bath) and warm to about 75°C. Heat the water to 75°C and add the sodium lauryl sulfate, propylene glycol, methylparaben, and propylparaben. Add the aqueous phase and stir until congealed. IV. Water-soluble ointment (polyethylene glycol ointment, USP 14) Polyethylene glycol 4000 (Carbowax 4000) 50%... 

Charge 40% of the propylene glycol to an appropriately sized stainless steel and add methylparaben and propylparaben with mixing, and mix until dissolved. 

Add the methylparaben and propylparaben. Rinse the containers with some of the remaining water if necessary. Stir until dissolved, maintaining temperature at about 80°C. 

Clotrimazole Mycelex 3 Cetyl alcohol, polysorbate 60, PEG 400 stearate Methylparaben and propylparaben... 

The preservatives methylparaben and propylparaben are used in artificial tears and nonmedicated ointments.They can cause allergic reactions and are unstable at high pH. 

The activity of the parabens increases with increasing chain length of the alkyl moiety, but solubility decreases. Activity may be improved by using combinations of parabens since synergistic effects occur. Ethylparaben is commonly used with methylparaben and propylparaben in oral and topical formulations (such mixtures are commercially available for example, Nipasept (Nipa Laboratories Inc.). Activity has also been reported to be improved by the addition of other excipients see Methylparaben for further information. 

Hydroxypropyl cellulose in solution demonstrates some incompatibility with substituted phenol derivatives, such as methylparaben and propylparaben. The presence of anionic polymers may increase the viscosity of hydroxypropyl cellulose solutions. 

Methylparaben and propylparaben are affirmed GRAS Direct Food Substances in the USA at levels up to 0.1%. All esters except the benzyl ester are allowed for injection in Japan. In cosmetics, the EU and Brazil allow use of each paraben at 0.4%, but the total of all parabens may not exceed 0.8%. The upper limit in Japan is 1.0%. 

Saad, B., Bari, M.F., Saleh, M.I., Ahmad, K., and Talib, M.K. 2005. Simultaneous determination of preservatives (benzoic acid, sorbic acid, methylparaben and propylparaben) in foodstuffs using high-performance liquid chromatography. Journal of Chromatography A 1073 393-397. 

The most frequently used antimicrobials found in commercial shampoos are parabens, methylparaben and propylparaben. Mixtures of different preservatives provide broader protection against a wider spectrum of microorganisms and have been proven to be the most effective method to ensure product robustness [100], The level of preservative necessary depends on the composition of ingredients, total alcohol level, pH value, and water activity. 

Another strength of cream contains fluocinolone acetonide 0.25 mg/g in a water-washable aqueous base of butylated hydroxytoluene, cetyl alcohol, citric acid, edetate disodium, methylparaben and propylparaben... 

Propylene glycol, diazolidinyl urea, methylparaben, and propylparaben 10.00... 

Methylparaben and propylparaben are used as preservatives in foods, beverages, and cosmetics ... 

Other regulatory bodies such as the U.S. FDA (Food and Drug Administration) have set the limit of methylparaben and propylparaben at 0.1% w/w. In cosmetics, the EEC and Danish cosmetic regulations give a combined maximum limit of 0.8% w/w for all the parabens. Various regulatory bodies set the maximum levels of all the parabens in pharmaceutical products at 1% w/w [3]. For this reason, robust analytical methods are required for the determination of parabens in a variety of matrices. 

Alongside this recent regulation, there are a number of cosmetic standards issued by the Bureau of Indian Standards (BIS). These standards, frequently old and not updated to take into account modem technology, concern either cosmetic ingredient (e.g. standards IS 4653 1985 and IS 6333 1985 concerning methylparaben and propylparaben used in cosmetics, respectively) or finished product (see list in Table 2.1.11). They describe the specifications to which ingredients or finished cosmetics must conform, as well as the tests needed to control conformity to standards, including some physical/chemical analysis methods. 

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