In this study, the release experiments of drug were operated in the phosphate buffer solutions of pH 1.2 by using drug carriers(chitosan, chitosan hydrochloride, and sulfonated chitosan) coated by poly(DL-lactide) with prednisolone for delivery drug. The release time of according to the kinds of drug carrier was delayed in the order of chitosan, sulfonated chitosan, and chitosan hydrochloride. The release time of drug from coating drug carriers was more delayed that of drug from no coating in pH 1.2. In short, the formulation allows biodegradable coated monolithic polymeric matrices to suppress the burst effect of the drug release mechanism, which led to the sustained release pattern.