The purpose of the present study was to design mucoadhesive chitosan microspheres containing amoxycillin. Chitosan microspheres with a small particle size and good sphericity were prepared by a spray-drying method followed by chemical treatment with a chemical crosslinking agent (glutaraldehyde). Parameters affecting the extent of crosslinking were the crosslinking time and the concentration of the crosslinker agent. Crosslinked spray-dried chitosan microspheres were analyzed for their morphological aspects, particle size, drug entrapment efficiency, swelling percent and in vitro drug release. Batch M4 with a drug polymer ratio of 1:2, dissolved in minimum concentration of acetic acid solution treated with glutraldehyde, was found to be optimal giving controlled drug release for 10 h. It was found that both the increase of glutaraldehyde concentration and crosslinking duration decreased the swelling capacity of chitosan microspheres. This could be directly correlated to drug release from the microspheres.Cilj ovog rada bio je priprava mukoadhezivnih kitozanskih mikrosfera amoksicilina. Mikrosfere male veličine čestica i dobre sferičnosti pripravljene su metodom sušenja sprejom, te obradom s glutaraldehidom kao sredstvom za umrežavanje. Stupanj umrežavanja ovisio je o vremenu umrežavanja i koncentraciji sredstva za umrežavanje. Umreženim kitozanskim mikrosferama određen je oblik, veličina čestica, količina uklopljenog lijeka, postotak bubrenja i in vitro oslobađanje ljekovite tvari. Pripravak M4 s optimalnim svojstvima i kontroliranim oslobađanjem amoksicilina tijekom 10 sati pripravljen je pomoću smjese polimera omjera 1:2 otopljenih u razrijeđenoj octenoj kiselini, te umreženih pomoću glutraldehida. Povećanje koncentracije glutaraldehida i trajanja umrežavanja smanjuje sposobnost bubrenja kitozanskih mikrosfera, što je u izravnoj korelaciji s oslobađanjem lijeka iz mikročestica
