A review on enteric coated liposomes

Liposomes are novel drug delivery system which delivers the drug directly to the place of action. The liposomes are colloidal carriers with a diameter ranging from 0.01 to 5.0 μm. Liposomes can be formulated using different approaches like thin-film hydration method, reverse phase evaporation method, solvent injection method etc. However, this drug delivery mechanism fails to transport the medication to the GIT when liposomes are employed to treat diseases related to the GIT, because of the medication release into acidic environments. In this instance, the liposomes are coated using the enteric coated polymer. The word “enteric” indicates small intestine; therefore enteric coatings prevent release of medication/drug before it reaches the small intestine. At low pH levels, the enteric coated polymer continues to unionize and stays insoluble. Enteric-coated liposomes are formulated for avoiding the first pass metabolism, gastric irritation and degradation and to direct the drug to the intestine. The Polymer used for enteric coating are cellulose acetate phthalate (CAP), polyvinyl acetate phthalate (PVAP), hydroxypropyl methylcellulose phthalate (HPMCP), acrylate polymer etc. The review focuses on the general overview of enteric coated liposomes, their manufacturing method, characterization, and their application in the drug delivery system