Enteral insulin delivery by microspheres in 3 different formulations using Eudragit L100 and S100

Three types of insulin microspheres (IMS) were prepared in order to deliver insulin selectively in the intestinal tract using copolymers having pH-dependent solubility, Eudragit L100 (L), Eudragit S100 (S) and a 1:1 mixture of these (LS). In a release study, the insulin release rate from S-IMS was much slower than that from L-IMS at a pH below 7.0. At a pH of 7.5, all the IMS released more than 90% of the insulin within 60 min. Thus, the three...