Preparation and evaluation of an oral delivery system for time-dependent colon release of insulin and selected protease inhibitor and absorption enhancer compounds.
The aim of this work was to prepare and evaluate an oral dosage form intended for time-dependent colon delivery of insulin along with a selected protease inhibitor (camostat mesilate) and absorption enhancer (sodium glycocholate). A previously described release platform, which had proven potentially suitable for the protein delivery, was exploited. Insulin compatibility with the above-mentioned adjuvants was preliminarily evaluated. For this purpose, the drug and its main degradation products were assayed by HPLC in insulin powder mixtures with camostat mesilate and/or sodium glycocholate stored 12 months at 4 degrees C. No significant decrease in protein content or increase in degradation product percentages beyond Eur. Ph. 6th Ed. limits was highlighted. Moreover, calorimetric studies performed on physical and compacted binary insulin mixtures with camostat mesilate and sodium glycocholate showed that the thermal behavior of both adjuvants was unchanged. Subsequently, tablet cores with differing compositions were prepared and spray-coated with an aqueous HPMC solution in order to obtain pulsatile delivery systems. The coated units were demonstrated to concurrently release the drug and the adjuvants in a prompt and quantitative mode after consistent lag times. Based on these results, the device was proven a potential candidate for colon delivery of insulin and the selected adjuvants.
Del Curto
Maria Dorly
MD
Dipartimento di Scienze Farmaceutiche P. Pratesi, University of Milan, Via G. Colombo 71, Milan 20133, Italy.
Maroni
Alessandra
A
Foppoli
Anastasia
A
Zema
Lucia
L
Gazzaniga
Andrea
A
Sangalli
Maria Edvige
ME
D000284:Administration, Oral; D002151:Calorimetry; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D003106:Colon / Q000378:metabolism*; D004339:Drug Compounding; D016503:Drug Delivery Systems; D004344:Drug Incompatibility; D005079:Excipients; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D007328:Insulin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D007408:Intestinal Absorption / Q000187:drug effects*; D011480:Protease Inhibitors / Q000008:administration & dosage* / Q000493:pharmacokinetics; D012995:Solubility; D013607:Tablets; D013817:Thermography
D005079:Excipients; D007004:Hypoglycemic Agents; D007328:Insulin; D011480:Protease Inhibitors; D013607:Tablets