Preparation of a multistructural film with CM‐chitosan and PVA, and in vitro ornidazole release from the carrier

In this study, carboxymethyl‐chitosan microspheres (CCMS) were prepared by a method of emulsification combined with two‐step solidification and loaded ornidazole as model drug. The ornidazole loaded CCMS were incorporated into Poly(vinyl alcohol) (PVA) film to form a multistructure drug system for feasibly releasing drug in local site. The appearance, particle size, drug loading and encapsulation efficiency, and drug release profiles of CCMS could be tailored in the preparation. Appropriate enhancement of drug amount in the microsphere would bring optimum effect on drug loading percentage and release profile. The use of dimethylsulfoxide (DMSO) could produce spherical spheres with smooth surface and small size, but depress the drug loading and encapsulation efficiency and hasten the burst drug release. For the multistructure carrier materials, the outer PVA film rapidly breaks up to pieces after about 30 min of placement in water and then entirely dissolved. Drug release from the multistructure carriers was a little faster than that from the pure CCMS. Ornidazole release from the carriers performed a burst release in the initial 2 h then followed a gradual release. It could be achieved the controlled release pattern of ornidazole by dispersing the well prepared CCMS into PVA film.