Wax, Yellow

Category

Controlled-release Agents; Polishing Agents; Stabilizing Agents; Stiffening Agents

Grade

Pharmceutical Excipients

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.

UNII

2ZA36H0S2V

Chemical Name

Yellow beeswax

CAS Number

8012-89-3

Synonyms

Apifil; cera flava; E901; refined wax

Administration route

Oral and topical

Dosage Form

Oral capsules and tablets, and topical preparations

Stability and Storage Conditions

When the wax is heated above 150℃ esterification occurs with a consequent lowering of acid value and elevation of melting point. Yellow wax is stable when stored in a well-closed container, protected from light.

Source and Preparation

Yellow wax is a natural secretion of bees and is obtained commercially from honeycombs. Honey is abstracted from combs either by draining or centrifugation, and water is added to the remaining wax to remove soluble impurities. Hot water is then added to form a floating melt, which is strained to remove foreign matter. The wax is then poured into flat dishes or molds to cool and harden.

Applications

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, and yellow wax has also been used in multiparticulate controlled-release dosage forms of chlorphenamine maleate. Yellow wax forms a soap with borax.

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.

Incompatibilities

Incompatible with oxidizing agents.