Study on poly(vinyl alcohol)/carboxymethyl-chitosan blend film as local drug delivery system.

The distinguishable films composed of poly(vinyl alcohol) (PVA) and carboxymethyl-chitosan (CMCS) were prepared by blending/casting method, and loaded with ornidazole (OD) as local drug delivery system. In vitro test, the blend films showed pH-responsive swelling behavior and moderate drug release action, and also exhibited a little antimicrobial activity against E. coli and S. aureus strains. Those characteristics of CMCS/PVA blend films were essentially governed by the weight ratio of CMCS and PVA. Increasing the content of PVA in blend film would decrease swelling and decelerated the drug release. However, increasing the content of CMCS would enhance the antimicrobial activity. The biocompatibility and bioactivity of the blend film were also evaluated using rabbit blood and Wister rats. This blend drug system was of no hemolysis, no toxicity to rat periodontia and no cytotoxicity to the rat muscle. After subcutaneously implanting the blend drug films in Wister rat, the systems kept a good retention at the application site and maintained high drug concentration in long time (5 days) which was longer than the period of drug released in vitro (160 min).