A Review on Enteric Coated Pellets Composed of Core Pellets Prepared by Extrusion-Spheronization

Enteric coated dosage form bypasses the stomach and releases the drug into the small intestine. Advantages of enteric coated pellets in comparison with enteric coated tablets are a) Pellets provide rapid onset of action and faster drug release due to the smaller size than tablets and b) Pellets exhibit less residence time of acid-labile drugs in the stomach compared to tablets. Dosage form coat can be damaged by longer resistance time in the stomach. The present review summarizes the current state of enteric coated pellets where core pellets are prepared by extrusion-spheronization technique and the enteric coating is applied in a fluidized bed processor. Two approaches are involved in the preparation of core pellets. In the first approach, a mixture of drug and excipient(s)/co-processed excipient is passed through extruders to prepare core pellets. In the second approach, excipient core pellets are prepared by extrusion technique and the drug is layered onto it before the enteric coating. The excipients present in the core pellets decide immediate or extended release of drug in the intestine. The coprocessed excipient pellets provide less batch variability and provide a platform for layering of many drugs before enteric coating. Some patents included enteric coating pellets [CN105456223 (A), CN105596310 (A), CN105616371 (A), CN105663095 (A), CN101611766B, CN106511862 (A), CN106668018 (A), CN106727381 (A), CN106924222 (A), TW200624127 (A), US 2017/0165248A1, US 2017/0224720A1] are discussed.