LONG-ACTING DELIVERY SYSTEM OF INTERFERON - IFN MINIPELLET

The optimal composition for an interferon (IFN) minipellet which released IFN with a high bioavailability and a long half-life was designed. Minipellets are cylindrical solid dosage forms using collagen as a biodegradable carrier material. A monolithic collagen matrix releases the incorporated drugs over long periods of time, Minipellets of various composition containing IFN were prepared and IFN release from minipellets was examined. Human serum albumin (HSA) added to the collagen matrix was shown to promote and maintain IFN release. In vivo experiments demonstrated that serum IFN concentrations were maintained at elevated levels for 7-10 days after administration of IFN minipellets containing 30% (w/w) HSA in the matrix. Pharmacokinetic studies showed that the IFN minipellet had good dose-dependency and reproducibility in serum drug level profiles. The IFN minipellet is expected to offer a significant advantage in IFN therapy because the peak IFN serum concentrations are attenuated, allowing prolonged effective dosing and reducing side effects. The increasing popularity of IFN treatment calls for the development of a formulation and a method of administration that reduces the burden on the patients. Therefore, a long-acting IFN delivery system requiring weekly subcutaneous administrations seems to be highly useful in a clinical setting.