Development Of Transdermal Drug Deliver System

Peptides and proteins are playing an increasingly important role in modern clinical therapy with the development of bio-engineering techniques. However, these oral drugs are susceptible to enzymatic degradation of the gastrointestinal tract and first pass effect of liver, as well as their poor stability and short biological half-life, pose new challenges for clinical practice to delivered drugs to the human body. The transdermal drug delivery route is a safe, effective and convenient method of administration, which overcome these shortcomings above. Unlike other mucosa, the skin contains fews of proteolytic enzymes, which is conducive to maintaining the stability of the drug. However, due to the barrier function of stratum corneum in skin, as well as the high molecular weight of these drugs and the high water solubility, it is difficult to achieve the desired results with the aid of passive diffusion and permeability penetration agent to increase the permeability of these drugs. Until the last several decades, the physical penetration techniques were introduced to the field of transdermal drug delivery and achieved a significant development, made it possible for the transdermal delivery of macromolecular peptide drugs.As the largest organ of human body, the skin contains small amounts of proteolytic enzymes, which is conducive to maintaining the stability of the drug. The percutaneous deliver of peptides and proteins avoid the shortcomings of subcutaneous injection and the digestive tract medication, provides a convenient and effective way for the administration of protein drugs. However, the stratum corneum of the skin only allows the penetration of the lipophilic small molecule drugs, the molecular weight of protein drugs with hydrophilic can’t penetrate into the body through the skin stratum corneum. In order to overcome the barrier function of skin, chemical penetration enhancers, sonophoresis, iontophoresi and electroporation were used to increase the permeability of the skin to achieve an desire drug penetration.The purpose of this study is to design a transdermal drug delivery systerm based on microcontroller. The MCU STC12C5S60S2was used as the control core to implement functional modules design of electroporation, iontophoresis, and sonophoresis. The ions, macromolecular drugs penetrated the skin barrier with synergies in three physical methods, transported to the diseased tissue and organs in specified direction, quantity and speed, to achieve local tissue and systemic treatment. Through software and hardware design of each functional module, the transdermal drug delivery systerm with variable electroporation intensity, iontophoresis intensity, ultrasonic intensity, treatment time was completed. While deliver the drug effective, the system maintaining drug activity and drug improve bioavailability.This article describes the development of the instrument in the following aspects. The first aspect, The theoretical basis of the instrument design, including the drug transdermal penetration process, the concepts of the transdermal deliver physical techniques mechanism and influencing factors were analysis. The second aspect, the overall structure and function of the system were introduced in details from the view of hardware design. Then the designs of electroporation, iontophoresis, sonophoresis and the users’ interfaces were introduced. The third aspect, from the perspective of software design, programming environment and programming language of the instrument design were introduced. According to the modular design of the programming ideas, the main program and the function of each subroutine were designed with C language, which made the software structure clear, readable and easy to debug and maintain. The last aspect, the interference analysis instrument was done and the solutions of interference were proposed. Then the corresponding tests were performed to a variety of system output signal to determine whether the output of the system to meet the requirements. The test results were fed back to all aspects of the design process to constantly improve the design of the instrument.The microcontroller was used as the control core of transdermal drug delivery system. Enhancement techniques such as electroporation, iontophoresis, sonophoresis aid in the delivery of proteins by overcoming the skin barrier in different ways. Through reasonable design on software and hardware, achieving synergistic effect of these enhancement techniques, improving efficiency of drug delievery. The prototype of transdermal drug delivery system was developed. The system is easy to operate. Controlled non-invasive administration using more patient-friendly advanced delivery technologies may improve compliance. By adjusting the treatment parameters, it can be used for a variety of drugs, providing the potential for individualized therapy.