Purpose: To evaluate the in-vitro and in-vivo properties of chitosan and glutamate-chitosan microspheres as the drug delivery system able to obtain the direct nose-to-brain transport of a new macrolide, Rokitamycin. Methods: From our recent studies resulted that drug-loaded microspheres, prepared by spray-drying of the 0.25% (w/v) feed-solution and with drug-polymer ratio of 1-4 (w/w) were characterised by morphology, dimension and size distribution suitable for nasal administration. These formulations increase the drug dissolution rate, quickly absorb water and swell. The microspheres were chosen for ex-vivo and in-vivo studies. An extraction method from blood and cerebral-spinal fluid and a HPLC analysis method of Rokitamycin was expressly set up. In-vitro and in-vivo blood stability of the drug was evaluated. Preliminary tests of in-vivo nasal administration of microspheres on rats, compared with drug alone, were carried out. Results: The Rokitamycin encapsulation into the microspheres increases its poor ex-vivo permeability through nasal sheep mucosa. The drug is stable in human whole blood till 8 hour of incubation. On the contrary, after intravenous injection in rats, the Rokitamycin is widely degraded such to determine a half-life of 14 min. In-vivo results of nasal administration of microspheres show that only glutamate-chitosan nanoparticles allow to btain the absorption of the drug and its uptake in the central nerous system Conclusions: These results show that the new antiamoebic drug, Rokitamycin, can be encapsulated into microspheres that can be administrated by nasal route as potential delivery system for obtaining the brain targeting of the drug.
Influence of chitosan properties on the in vivo rokitamycin absorption from nasal microspheres
FERRARO, Luca Nicola;DALPIAZ, Alessandro
2008
Abstract
Purpose: To evaluate the in-vitro and in-vivo properties of chitosan and glutamate-chitosan microspheres as the drug delivery system able to obtain the direct nose-to-brain transport of a new macrolide, Rokitamycin. Methods: From our recent studies resulted that drug-loaded microspheres, prepared by spray-drying of the 0.25% (w/v) feed-solution and with drug-polymer ratio of 1-4 (w/w) were characterised by morphology, dimension and size distribution suitable for nasal administration. These formulations increase the drug dissolution rate, quickly absorb water and swell. The microspheres were chosen for ex-vivo and in-vivo studies. An extraction method from blood and cerebral-spinal fluid and a HPLC analysis method of Rokitamycin was expressly set up. In-vitro and in-vivo blood stability of the drug was evaluated. Preliminary tests of in-vivo nasal administration of microspheres on rats, compared with drug alone, were carried out. Results: The Rokitamycin encapsulation into the microspheres increases its poor ex-vivo permeability through nasal sheep mucosa. The drug is stable in human whole blood till 8 hour of incubation. On the contrary, after intravenous injection in rats, the Rokitamycin is widely degraded such to determine a half-life of 14 min. In-vivo results of nasal administration of microspheres show that only glutamate-chitosan nanoparticles allow to btain the absorption of the drug and its uptake in the central nerous system Conclusions: These results show that the new antiamoebic drug, Rokitamycin, can be encapsulated into microspheres that can be administrated by nasal route as potential delivery system for obtaining the brain targeting of the drug.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
