Novel chitosan-based delivery systems for the nasal administration of a LHRH-analogue

This paper investigates the nasal absorption of the LHRH-analogue, gosereli n, and the feasibility of producing a formulation with improved nasal bioav ailability. It is shown that the use of chitosan in a nasal delivery system has the ability of providing significantly enhanced nasal absorption in th e sheep model. Bioavailability of 11.6, 25.6 and 36.6%, respectively, were obtained for a goserelin chitosan solution formulation, a dry blend of chit osan and goserelin, or goserelin freeze-dried with a cross-linked chitosan microsphere formulation. It is concluded that nasal goserelin formulations that show highly therapeutically relevant serum goserelin levels can be pro duced. Such formulations would be of great benefit to the treatment of vari ous diseases such as endometriosis, prostate cancer and cryptorchidism or i n NF treatment regimens.