Development of a Wireless Controlled Iontophoretic Drug Delivery System

Introduction

The term iontophoresis has become a common terminology in the medical fraternity. The process involves delivery of drug molecules (having a physiological activity) for the treatment of a disease by passing an electric current through the human body. For this purpose, the human body is connected with a current injecting electrode and a reference electrode (required for the completing the electrical path). These electrodes are connected to an electrical circuit, which is capable of providing a voltage gradient across the electrodes. This voltage gradient is responsible for pushing the ionic drug molecules into the body. This process was first described by LeDus (1900) (Ciach & Moscicka-Studzinska, 2011; Leduc, 1900). The movement of the charged drug molecules occurs in such a fashion that they move towards the electrode, which is oppositely charged. Hence, care should be taken to place the drug under a suitable electrode. Mistakenly, if the drug molecules are placed under the electrode, which is counter charged, then no delivery of drug will happen. As a matter of fact, the cationic and the neutral drug molecules should always be placed under the positive electrode, whereas, the anionic drug molecules should always be placed on the negative electrode. The delivery of a drug by this method is governed by two phenomena, namely, electromigration and electroosmosis. Electromigration is a mass transfer process, which occurs due to the electrostatic interaction. As per this process, the charged drug molecules are electrostatically repelled by the active electrode (having the same charge) into the body. This process is predominant if the drug molecules are charged species. The process of electroosmosis has predominant effect in tissues, which are negatively charged (e.g. skin and buccal mucosa). As the ionic drug molecules move through the tissues under the electric field, the movement of the cationic molecules will be enhanced, whereas, the movement of the anionic molecules will be retarded. This influences the movement of the solvent molecules and other uncharged molecules. Such transfer is reported to occur by simple momentum transfer (Ciach & Moscicka-Studzinska, 2011). This phenomenon allows delivery of neutral drug molecules. Since the tissues are negatively charged, the delivery efficiency of cationic molecules has been found to be much higher as compared to the anionic drug molecules.

In the last two decades, there has been a considerable advancement in the technologies associated with the microcontroller design. This has allowed in developing current injecting devices at affordable prices. Due to this reason, along with the smooth delivery of drugs into the systemic circulation in a non-invasive manner, the use of these devices has been explored for personal healthcare, which was previously mainly confined to the treatment of the patients in the hospitals. The iontophoretic devices can find the application in the management of the patients in the hospitals. In most of the hospitals, there is a shortage of nursing staff. This issue is valid not only for developing countries but also for developed countries. Due to this reason, many scientists are working on the development of medical devices which are capable of reducing the workload of nursing staff. Herein, we propose to develop a wireless controlled iontophoretic delivery system. The control system will be able to manipulate the operation of the iontophoretic device from a remote location (e.g. nursing station of an intensive care unit (ICU)). The controlled system has been made to control multiple iontophoretic devices.