The Adsorption and Release Characteristics of CPFX in Porous Starch Produced Through Different Drying Methods

The drug adsorption and release characteristics of porous starches produced through hot air drying, spray drying, and vacuum freeze drying were investigated using ciprofloxacin as model drug. A UV/visible spectrophotometer, Fourier-transform infrared spectrometer, differential scanning calorimeter, and X-ray diffractometer were used to determine the drug adsorption/release, drug/starch interaction, glass transition, and crystallinity of porous starch samples. The amount of ciprofloxacin adsorbed in three different porous starches was 5.58%, 8.91%, and 11.43%, respectively. The ciprofloxacin-loaded porous starches had glass-transition-related endothermic peaks between 55 degrees C and 65 degrees C and melting-related endothermic peaks between 120 degrees C and 150 degrees C. Up to 75% of the loaded ciprofloxacin was released from the freeze-dried sample within 30hrs. The freeze-dried porous starch also showed higher ciprofloxacin loading rate, higher glass transition temperature, and higher ciprofloxacin release rate. A two-phase dynamic drug release model was found to satisfactorily fit the release kinetics of ciprofloxacin (R-2>0.995).