DEVELOPMENT AND INVESTIGATION OF A THERMORESPONSIVE CHOLESTERYL OLEYLCARBONATE-EMBEDDED MEMBRANE

Cholesteryl oleyl carbonate (COC) was embedded in a cellulose nitrate membrane for the purpose of developing a drug delivery system with a t hermal stimulus response. The thermophysical properties of COC were de termined by thermal analysis and microscopic Fourier transform infrare d spectroscopy with differential scanning calorimetry (Micro FTIR-DSC) to confirm its thermo-responsive property. The COC-embedded membrane was prepared by filtrating a certain amount of COC chloroform solution through the cellulose nitrate membrane using a vacuum filtration meth od. The thermo-responsive functions of COC-embedded membranes were inv estigated using a step-wise temperature change between 10 degrees C an d 25 degrees C (below and above the gel-liquid crystal phase transitio n temperature of COC). The results indicate that the amount of COC ads orbed increased linearly with the increase of the COC concentration us ed. The permeation rate of salbutamol sulfate through the COC-embedded membrane was controlled by the amount of COC absorbed in the cellulos e nitrate membrane, which could be confirmed by the observations of sc anning electron microscopy (SEM) and contact angle measurements. The p ermeation of salbutamol sulfate through the membrane could be sensitiv ely controlled by temperature changes. This implies the COC-embedded m embrane may be used as a thermally on-off switching membrane for a sti muli-response controlled drug delivery system.