Comparison study of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres

Abstract

To compare two microspheres of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin loaded theophylline as pulmonary sustained drug delivery carriers, the characteristics and ciliotoxicity were studied. The drug loadings of chitosan/ β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres were 21.09% and 21.42%, and the encapsulation efficiencies were 91.40% and 92.80%. The distributions of 50% (d 0.5 ) of chitosan/β-cyclodextrin and carboxymethyl chitosan/β-cyclodextrin microspheres were 4.89 and 5.83 μm, respectively. Both microspheres showed spherical shape with smooth or wrinkled surfaces. FT-IR of chitosan/β-cyclodextrin microspheres demonstrated that theophylline had formed hydrogen bonds with chitosan and β-cyclodextrin, while for the carboxymethyl chitosan/β-cyclodextrin microspheres theophylline had interaction with carboxymethyl chitosan. The moisture absorption showed that an equilibrium was reached within 24 h. The two microspheres possessed better adaptability. In vitro release of theophylline from chitosan/ β-cyclodextrin microspheres was slower than that from carboxymethyl chitosan/β-cyclodextrin microspheres at pH 6.8.

Molecular Recognition‐Driven Membrane Processes

“…Studies on the characteristics and ciliotoxicity of these systems evidenced an high drug loading and encapsulation effi ciency and suggested that them should be eff ective as for sustained pulmonary drug carriers [49].…”