Theophylline release from cellulose acetate membranes that modified by nano-SiO2

In this study, transfer of theopyhlline from biologically compatible CA membranes modified by nano-silisyumdioksit (n-SiO2) was investigated. In order to obtaine modified CA membranes that has low permeability for convenient theophylline tranfer, the n-SiO2 that was added at definite proportions were removed from the membranes by using suitable solvents and ultrasonic waves. For this aim suitable solvents that remove n-SiO2 without damaging the original membrane material were investigated. It was determined that the amount of theophylline tranfered from unit area of the membranes from which n-SiO2 was removed increased from 0.9x10-7 kg/m2s to 5.79x10-5 kg/m2s. The effect of the thickness of the membrane, the amount of n-SiO2 used in the modification process, pH, concentration of theophylline and temperature on the release of theophylline from the n-SiO2 modified CA membranes were examined. As the thickness of the membrane increased the transfer of theophylline decreased in accordance with Fick' s law. It was determined that there was no change in the transfer of theophylline with the increase in the amount of n-SiO2 used in the modification of the CA membrane. When the pH of of reciever compartment was 2.10 and 7.40 high transfer of theophylline was obtained; there was no significant effect in the transfer of theophylline when there occurs a change in the pH of donor compartment. Increse in theophyllineconcentration and temperature increased the amount of theophylline transferred from the membranes.Key Words : Cellulose Acetate, Theophylline, Nano-Silicon Dioxide, Controlled Release, Membrane