Food additives Europe numbers E901
Functional Category
Controlled-release agent; stabilizing agent; stiffening agent.
Applications in Pharmaceutical Formulation
White wax is a chemically bleached form of yellow wax and is used in similar applications: for example, to increase the consistency of creams and ointments, and to stabilize water-in-oil emulsions. White wax is used to polish sugar-coated tablets and to adjust the melting point of suppositories. White wax is also used as a film coating in sustained-release tablets.(1) White beeswax microspheres may be used in oral dosage forms to retard the absorption of an active ingredient from the stomach, allowing the majority of absorption to occur in the intestinal tract. Wax coatings can also be used to affect the release of drug from ion-exchange resin beads.(2–4) See also Wax, Yellow.
Description
White wax consists of tasteless, white or slightly yellow-colored sheets or fine granules with some translucence. Its odor is similar to that of yellow wax but is less intense.
Stability and Storage Conditions
When the wax is heated above 1508C, esterification occurs with a consequent lowering of acid value and elevation of melting point. White wax is stable when stored in a well-closed container, protected from light.
Incompatibilities
Incompatible with oxidizing agents.
Safety
White wax is used in both topical and oral formulations, and is generally regarded as an essentially nontoxic and nonirritant material. However, although rare, hypersensitivity reactions to beeswax (attributed to contaminants in the wax) have been reported.(5,6)