OBJECTIVETo develop a best chitosan film for using as a drug sustained-release system through the evaluation of the sustained-release property, degradation property, and cytotoxicity to osteoblast.

METHODSOrthogonal experiments were designed to determine the best combination of chitosan film preparations. Drug release rate was determined with Coomassie brilliant blue G250. In a separate study, chitosan films were placed into the test tubes with buffer solution and 10(7) U/L lysozyme. The degradation rate was calculated. Osteoblasts derived from fetal rat calvarial were cultured on chitosan films. Cell proliferation was tested by methyl thiazolyl tetrazolium (MTT) assay. The relative growth rate was calculated and the cytotoxicity was graded.

RESULTSThe best processing condition was 1% acetic acid, chitosan concentration of 2 mg/mL, 6% sodium tripolyphosphate (STPP) concentration, and cross-linking time of one hour. The resulting chitosan film released 33.13% of bovine serum albumin (BSA) within 8 d, 36.73% of BSA within four weeks and the cytotoxicity grade was 0 or 1.

CONCLUSIONThis chitosan film possesses good sustained release property, and a good degradation rate.