Methylparabens

Preservatives. Most products must contain preservatives to ensure that yeasts, molds, and bacteria do not thrive in them. These preservatives include alcohol, methylparaben, propylparaben, DMDM hydantoin, diazohdinyl urea, and imidazohdinyl urea. The parabens have limited solubiUty in water, eg, 0.25% for methylparaben and 0.05% for propylparaben (22). If these levels are exceeded in the formula, then the addition of solvents is needed to ensure clear, stable products. 

Lente insulin is an almost colorless suspension of a mixture of characteristic crystals predominandy 10—40 p.m in maximum dimension, and many particles that have no uniform shape and do not exceed 2 p.m in maximum dimension. On a wt/vol basis, it contains 0.15—0.17% sodium acetate, 0.65—0.75% sodium chloride, 0.09—0.11% methylparaben, and 0.20—0.25 mg of 2inc of which 40—65% is in the supernatant Hquid. Its pH is 7.1—7.5. 

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%... 

Y. Kaminer, A. Apter, S. Tyano, E. Livni, and H. Wysenbeek, Delayed hypersensitivity reaction to orally administered methylparaben, Clin. Pharm., 1, 469 (1982). 

Methylophilus methylotrophus, 11 3 Methylotrophic yeasts, 72 479 Methylparaben, antimicrobial used in cosmetics, 7 831t Methyl Parathion... 

Ibuprofen, pseudoephedrine and chlorpheniramine are the drag substances have an effect as antihistaminic, nasal decongestant and antiinflammatory, respectively. The combination of these drags, is effective in cold, sinus and flu symptoms and used for upper respiratory infections. Nipagen (methylparaben) is widely used as... 

FIGURE 2.18 Separation of polar and acidic solutes on a classical RP and on shield phases. Columns Symmetry C8 and symmetry shield C8. Mobile phases 20% ACN, 10% HjO, 70% lOmM phosphate buffer pH 3 (v-v-v). 30% MeOH, 70% lOmM phosphate buffer pH 3 (v-v). Samples 1, 4-hydroxyisophthalic acid 2, acetylic salicylic acid 3, salicylic acid 4, phenol 5. methylparaben 6, dimethylphthalate. 

This assay is altogether more difficult since three active ingredients are involved and several excipients interfere in the analysis, including one major excipient (methylparaben), which is not removed in the extraction process. In addition the active ingredients are bases which have a tendency to interact with any uncapped silanol groups in the stationary phase and it is essential to use a column which is deactivated with respect to the analysis of basic compounds. The three active ingredients are all at different concentrations in the formulation so that attention has to be paid to selection of a detection wavelength at which each component can be detected. In this particular assay a DAD would be useful. 

The HPLC chromatogram of an extract from a linctus containing pseudoephedrine, dextromethorphan, triprolidine and methylparaben. ODS column 25 cm x 4.6 mm, mobile phase acetonitrile/0.05 M phosphate buffer pH 6.8 (35 65) 1 ml/min. UV monitoring at 260 nm. 

H3PO4 / 40 % acetonitrile at a flow rate of 1 mL/min. was used, and UV detection at 210 nm was used. The method was used for the separation of benzoic acid, methylparaben, ethylparaben, propylparaben, saccharin, sorbic acids, and /7-hydroxybenzoic acid. 

Contraindications Hypersensitivity to bentoquatam or any of its components such as methylparabens... 

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

This is a stable solution of digoxin specially formulated for oral use in infants and children. Each milliliter contains 50 meg (0.05 mg) digoxin. The lime-flavored elixir contains the inactive ingredients alcohol 10%, methylparaben... 

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