Name: Zein
CAS No: Zein [9010-66-6]
USP-NF: Zein
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Zein [9010-66-6]
Zein is a prolamin with a molecular weight of approximately 38 000.
Zein is used as a tablet binder in wet-granulation processes or as a tablet-coating agent mainly as a replacement for shellac. It is used primarily as an enteric-coating agent or in extended-release oral tablet formulations and other delivery systems.(1–3) Zein is also used in food applications as a coating agent. See Table I.
Zein is a prolamin obtained from corn (Zea mays Linne´ (Fam. Gramineae)). It occurs as a granular, straw- to pale yellow-colored amorphous powder or fine flakes and has a characteristic odor and bland taste. For amino acid composition.
See Table II.
Density 1.23 g/cm3 Melting point When completely dry, zein may be heated to 2008C without visible signs of decomposition. NIR spectra see Figure 1. Particle size distribution 100% less than 840 mm in size. Solubility Practically insoluble in acetone, ethanol, and water; soluble in aqueous alcohol solutions, aqueous acetone solutions (60–80% v/v), and glycols. Also soluble in aqueous alkaline solutions of pH 11.5 and above.
Zein should be stored in an airtight container, in a cool, dry place. It has not been reported to polymerize.(4,5)
Incompatible with oxidizing agents.
Zein is extracted from corn gluten meal with dilute propan-2-ol.
Zein is used in oral pharmaceutical formulations and food products, and is generally regarded as an essentially nontoxic and nonirritant material at the levels employed as an excipient. However, it may be harmful if ingested in large quantities.
Observe normal precautions appropriate to the circumstances and quantity of material handled. Zein may be irritant to the eyes and may evolve toxic fumes on combustion. Eye-protection and gloves are recommended.
GRAS listed. Included in the FDA Inactive Ingredients Database (oral tablets). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
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Zein is a protein derivative that does not contain lysine or tryptophan. For the approximate amino acid content of zein, see Table III. Zein may be safely consumed by persons sensitive to gluten. A study has investigated the adjuvanticity and immunogenicity of zein microspheres being researched as drug and vaccine carriers.(6) A specification for zein is contained in the Food Chemicals Codex (FCC).(7) The EINECS number for zein is 232-722-9.
