Abstract:In order to overcome the burst release of water-soluble drugs, reduce dosing frequency and improve curative effect,two new bond-linking type drug-loaded control-releasing systems: Chitosan-Captopril and Chitosan-Lysyl-Captopril were synthesized from captopril as a model drug and chitosan as carriers. The products were characterized by IR, 1H NMR and MS. The accumulation of drug release rates of Chitosan-Captopril are 59.2% in PBS buffer (pH=7.4) and 78.4% in HCl-KCl buffer (pH=1.2). The accumulation of drug release rates of Chitosan-Lysyl-Captopril are 55.2% in PBS buffer (pH=7.4) and 76.4% in HCl-KCl buffer (pH=1.2). The results show that the two kinds of drug-loaded systems eliminate the phenomenon of burst releasing and have excellent sustained release properties, which are expected to become the ideal control-releasing system of water-soluble drugs.