Acrycoat ERD: An advanced, new, enteric ready-to-use dispersion

It is suited for pharma pellets, tablets and soft gelatin capsules

An enteric coating, also known as the gastro-resistant coating is a barrier applied to oral medication that controls the location in the digestive tract where it is absorbed. The term “enteric” refers to the small intestine; therefore, enteric coatings resist the breakdown of medication before it reaches the small intestine.

Enteric coatings are employed when the drug substance is inactivated or destroyed in the acid secretion of the stomach or is particularly irritating to the gastric mucosa or when bypass of the stomach substantially enhances drug absorption.

Early approaches to preparing enteric-dosage forms involved treating gelatin capsules with formalin or coating tablets with shellac. Both of these approaches were unreliable since the solubility of the membrane (which is responsible for the enteric effect) can be unpredictable.

Materials used for enteric coatings include Cellulose acetate phthalate (CAP), Cellulose acetate trimellitate (CAT), Polyvinyl acetate phthalate (PVAP), Hydroxyl propyl methylcellulose phthalate (HPMCP), Hydroxyl propyl methylcellulose acetate succinate (HPMCAS), fatty acids, waxes, shellac, plastics and plant fibres.

Modern enteric coatings are usually formulated with synthetic polymeric material often referred to as polyacids. These polymers contain ionizable functional groups that render them water-soluble at a specific pH value.

This group of polymers are widely used for enteric coating applications as they contain free carboxylic acid groups that are ionized whenever the pH of the environment exceeds 5.5. They are produced by an emulsion-polymerization process and were first introduced for enteric coating applications by Lehmann and Dreher in the mid-1960s.