Flo Chemical Corporation

Making Freeman Zein for over 35 Years

Zein vs. Shellac

ZEIN is used in pharmaceutical manufacture as a tablet binder or granulating agent and in all types of tablet coatings, sometimes together with pharmaceutical plasticizers and other ingredients. These include sub-coating or seal coatings, film coatings, enteric and time-release coatings for medicinal tablets and seeds.

Since Zein is a protein extracted from corn, broad use applications have been allowed by the Food and Drug Administration without restrictions or limitations.  Zein coatings resist moisture and heat and have some resistance against bacterial and fungal growth

Traditionally, shellac has been used for sub or seal coating to protect cores prior to sugar coating as well as film and enteric coating. Shellac is obtained by the purification of Lac, the resinous secretion of the insect Laccifer Lacca Kerr (Fam. Coccidae).  Bleached (White) Shellac is prepared by dissolving the Lac in aqueous sodium carbonate, bleaching the solution with sodium hypochlorite and precipitating the Bleached Shellac with 2 N sulfuric acid. Removal of the wax, by filtration, during the process results in Refined Bleached Shellac.

ZEIN, a protein coating extracted from corn, is replacing shellac.  Zein has several advantages over shellac and will save you money as well. 

  • ZEIN is classified as Generally Accepted as Safe (GRAS) food ingredient by the U.S. FDA, USP Certified, Kosher, lactose-free, gluten-free, and biodegradable. 
  • ZEIN solutions are faster-drying, give better granulating and coating results and more stable, longer-lasting coatings than shellac.
  • The use of ZEIN enables you to claim "confectioner's glaze" "vegetable protein glaze" or 'corn or vegetable protein coating" on your label, with the knowledge that you are using a protein from the normal American diet.
  • Zein offers a better seal with an equivalent number of coats.
  • Disintegration time does not change on aging.
  • Zein is a more effective moisture barrier.
  • Zein is a more easily controlled raw material; lt's cleaner and has no contaminants.
  •  Zein is a better coating for troublesome raw materials such as hygroscopic ingredients that pick up moisture easily.

Other Advantages of Zein

  • Zein-coated tablets have excellent resistance to the combination of humidity and heat, and resist adherence to one another far better than sugar-coated and other film-coated tablets.
  • Engravings on Zein-coated tablets are more visible, as Zein does not tend to build up film within the engraving.
  • Zein film coatings resist mold, fungi and bacterial attacks under warm, humid conditions better than other film-coated tablets.
  • Zein film coating operations require a smaller capital investment in spraying equipment and less floor space than other coating systems.
  • Zein film coating with electronically-controlled equipment results in labor savings over other coating methods, particularly those involving lading.