Principles And Mathematical Modeling Of Transdermal Drug Delivery

With the development of technology and the improvement of people's living standards, health is paid more and more attention now. And people have much higher requirements on biomedical technology and medical products than before. In the therapeutic process of diseases, people not only require a good therapeutic effect, but also to minimize the negative effects and discomfort. Meanwhile, the development of biomedical engineering technology promotes the emergence of new medicinal preparation, such as protein-based and DNA-based drug or other biological synthesis preparation. Common ways, such as oral agents or intravenous injection can not play a good therapeutic effect on diseases. To meet these requirements, medical researchers begin to focus on transdermal drug delivery methods that have its unique advantages over other methods. Drugs in the transdermal drug delivery systems can avoid the metabolism because the liver is initially bypassed. Also, the risk of overdosage when drug enters the plasma is avoided. It helps to maintain a stable plasma drug concentration. Besides, transdermal drug delivery systems have smart shapes and it is easy to use by the patients themselves. Therefore, extensive researches on transdermal drug delivery are under way both at home and abroad.At the beginning, this paper summarizes the development history and hot research areas of transdermal drug delivery. Then introduces the principles of transdermal drug delivery process, and briefly describes the existing enhancing osmosis methods, including their principles and applications.There are two kinds of models in the field of transdermal drug delivery, they are mechanical models and empirical models. In this paper, we first simplify and abstract the diffusion process of drugs in the skin according to establish a mechanical model on the basis of the Fick's Law of Diffusion. And then solve the equation with restrictive initial conditions and boundary conditions. At last we analyze the influence of diffusion coefficient and surface drug concentration on the diffusion process and.absorption of drugs. The fourth chapter mainly discusses QSAR. We choose four structural parameters of drug, including molecular weight, octanol-water partition coefficient, the number of hydrogen bond donor and the number of hydrogen bond acceptor, as the input BP artificial neural network, while the percutaneous permeability coefficient as output. The established empirical model is used to predict the percutaneous permeability coefficient of a given drug. Compare with the measured values, it shows that the model is reliable.Discuss on transdermal drug delivery in this paper is limited to theoretical level, but the results of the models and analysis can provide necessary data reference for clinical trials. Especially at the beginning of development of transdermal drug formulations, it can help to reduce the number of tests, improve test efficiency and reduce consumption of experimental drugs and devices. At the same time, the results of the models can also promote and optimize the research of enhancing osmosis methods.