Preparation And Characterization Of The Controlled Release Membrane For Transdermal Drug Delivery Systems

As a new route of administration, transdermal drug delivery has obvious advantages compared with the conventional drug delivery methods of oral administration and injection. Controlled release membranes play an important role in the transdermal drug delivery system, because of the drug diffusion is controlled by the Controlled release membrane in many transdermal delivery systems.This thesis attempts to study two controlled release membrane for transdermal drug delivery systems, one is a piezoelectric PVDF porous membrane, which control the drug release by an electrical signal; the other one is TPU porous membrane, which control the drug release by mechanical stretch.Although there are many literatures report on the Polyvinylidene Fluoride(PVDF) ultrafiltration, microfiltration membrane or the piezoelectric PVDF film, but studies combined the piezoelectric properties of PVDF with the PVDF porous membrane are scarce. Piezoelectric PVDF porous membranes with the purpose of combining the piezoelectric properties with the PVDF porous membrane together have been prepared in this thesis. Six groups of piezoelectric PVDF porous membranes have been prepared, and the result of the water flux test reveal that the water flux of piezoelectric PVDF porous membranes will be larger when giving a positive-going electrical signal, and the water flux will be smaller after removing the electrical signal.The study result suggest that the piezoelectric PVDF porous membrane could be used as the controlled release membrane for transdermal drug delivery systems, and the release of drug molecules is controlled by an electric signal.The pore size of TPU porous membrane is controlled by mechanical stretching as the high flexibility and good elastic recovery rate of TPU. TPU porous membranes were prepared by immersion precipitation with five different mass fraction in casting solution. With the increasing mass fraction of TPU in casting solution,there is a decreasing in the pore size and the porosity, but an increasing in the mechanical strength. The water flux increased significantly when the TPU porous membrane was subjected to3times area of the original membrane in the tensile test. And after removal of the external force, the water flux was restored to the level of the same membrane before stretching. Therefore the TPU porous membrane may be used as the controlled release membrane for transdermal drug delivery systems, and the drug diffusion is controlled by mechanical stretching.In the end, the PVDF/TPU composite membranes were explored. Experiment results indicated that the poor miscibility of PVDF and TPU lead to inefficient performance of the PVDF/TPU blend membrane, as the casting solution is not uniform and the TPU or PVDF cast from the solution separately in some part of the blend membrane. In order to acquire high performance PVDF/TPU blend membrane, further study should focus on the improvement of miscibility of PVDF and TPU.