Food additives Europe numbers: E901
Functional Category
Controlled-release agent; polishing agent; stabilizing agent; stiffening agent.
Applications in Pharmaceutical Formulation
Yellow wax is used in food, cosmetics, and confectionery products. Its main use is in topical pharmaceutical formulations, where it is used at a concentration of 5–20%, as a stiffening agent in ointments and creams. Yellow wax is also employed in emulsions because it enables water to be incorporated into water-in-oil emulsions. In some oral formulations yellow wax is used as a polishing agent for sugar-coated tablets. It is also used in sustained-release formulations. Yellow wax coatings can be used to affect the release rate of drug from ion-exchange resin beads,(1) and yellow wax has also been used in multiparticulate controlled-release dosage forms of chlorphenamine maleate.(2) Yellow wax forms a soap with borax.
Description
Yellow or light brown pieces or plates with a fine-grained matt, noncrystalline fracture and a faint characteristic odor. The wax becomes soft and pliable when warmed. The PhEur 6.0 describes yellow wax as the wax obtained by melting the walls of the honeycomb made by the honeybee, Apis mellifera, with hot water and removing foreign matter
Stability and Storage Conditions
consequent lowering of acid value and elevation of melting point. Yellow wax is stable when stored in a well-closed container, protected from light.
Incompatibilities
Incompatible with oxidizing agents.
Safety
Yellow wax is generally regarded as an essentially nontoxic and nonirritant material, and is used in both topical and oral formulations. However, hypersensitivity reactions attributed to contaminants in the wax, although rare, have been reported.(3,4)