NOVEL DELIVERY SYSTEM FOR PROTEINS USING COLLAGEN AS A CARRIER MATERIAL - THE MINIPELLET

It is critical to develop effective delivery systems for biologically active peptides and proteins since most of them are rapidly destroyed by the body. In this study, interferon (IFN) was used as a model protein drug and matrix type formulations were prepared with natural biodegradable polymers, albumin, gelatin and collagen. The release of IFN from albumin and gelatin was much faster than that of collagen in vitro. The release of IFN from the collagen matrix varied with various processing conditions and were explained based on the density of collagen matrix. IFN was constantly released with a cylindrical solid dosage form prepared by extrusion and air-drying of a 30% (w/w) collagen solution of a high concentration in vitro. Pharmacokinetic studies in mice showed that the serum IFN concentration was maintained for a long time with this solid formulation called minipellet. The advantages of the minipellet are (1) carrier material is a biodegradable natural protein; (2) it is manufactured under mild processing conditions without any organic solvent or heating process; and (3) it is easily administered in the same way as conventional injections. Therefore, it is applicable to various kinds of biologically active peptides and proteins and expected to facilitate their potential therapeutic use.