Improvement of antiamoebic activity of Rokitamycin loaded in chitosan microspheres

Rokitamycin is a new macrolide containing 16 carbon atoms, strongly inhibitory forAcanthamoeba castellanii, an opportunistic protozoa of humans which cause primarily amoebic keratitis and chronic, but fatal, amoebic granulomatous meningoencephalitis. Chitosan microspheres were prepared as carriers to obtain a controlled release of rokitamycin, able to improve the antiamoebic activity of this drug. The microparticles werein vitrocharacterised and the efficacy of rokitamycin alone and encapsulated into microspheres on the growth rate ofAcanthamoeba castellaniwas evaluated. The results obtained suggest that spray-drying is a good technique for the preparation of microspheres loaded with rokitamycin. The loading of the drug into the polymeric network leads to an increase in the dissolution rate compared to drug raw material and improves and prolongs thein vitroantiamoebic activity of the drug. Thus, microspheres based on rokitamycin could be used in the therapy of systemic and topical infections caused byAcanthamoeba.