Calcium cross-linked carboxymethylchitosan/alginate microparticles as a system for the prolonged release of ketoprofen

In this work ketoprofen (KETO) loaded microparticles of carboxymethyl chitosan (CMCS) and alginate (ALG) cross-linked with CaCl2 were prepared at three compositions (CMCS-ALG 0:1, CMCS-ALG 1:2 and CMCS-ALG 1:1) to achieve the controlled release of this poorly soluble drug. CMCS with a substitution degree of 1.09 was prepared by direct alkylation of chitosan with monochloroacetic acid and isopropanol. KETO loaded microparticles were obtained by spray drying. They were characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. Microparticles were reticulated with 4 M CaCl2. Drug release was performed at pH 1,2 and 7.4. It was higher at pH 7,4. At this pH, CMCS-ALG 0:1microparticlesreleased almost 75 % of KETO in 20 hours whereas the other formulations released about 40 % of the drug. It is concluded that calcium cross-linked CMCS-ALG microparticles are a promising vehicle for designing a formulation for the prolonged release of KETO.