Liquid Nanosize Emulsion-Filled Enteric-Coated Capsules for Colon Delivery of Immunosuppressant Peptide.

Abstract

Present study aims at solubilizing slightly water-soluble peptide into a nanosize emulsion which is filled into a hard gelatin capsule in the form of preconcentrate. Further, liquid-filled capsule was dip-coated with ethyl cellulose and Eudragit S100 for colon targeting. An in vitro release profile was studied for selected formulations, i.e., Formulation A (5mg ethyl cellulose and 40mg Eudragit S100), Formulation B (10mg ethyl cellulose and 30mg Eudragit S100), and Formulation C (10mg ethyl cellulose and 20mg Eudragit S100). Formulations B and A showed an immediate release after 5 and 6h, respectively, which represents ileo-ceacal transit time. The nanosize of emulsion, i.e., below 100nm, was confirmed by transmission electron microscopy. Also, a phase transition of nanosize emulsion from water in oil to oil in water on dilution with water was observed through TEM. This novel approach of filling poorly water-soluble protein in solubilized form of nanosize emulsion preconcentrate into coated hard gelatin capsules for colon targeting has been reported first time. This approach could be a breakthrough for the better management of local intestinal pathologies.