Needle free monitoring of blood glucose through reverse iontophoresis

The frequent blood glucose monitoring is highly critical in order to understand the progression of diabetes mellitus and to minimize the probabilities of associated complications. This focuses to the fabrication of a new device for individual blood glucose monitoring. However, this technology turned out to be painful owing to its finger-stick technique, resulting in compromised patient compliance and inconsistent results. A paradigm shift from invasive to non-invasive technique to combat the above-stated limitations became an attractive tool for the researchers. The evolution of reverse iontophoresis to extract the essential plasma biomarkers as well as blood glucose through the skin was the result of the extensive efforts of the researchers as a means to monitor the blood glucose levels. The technology utilises delivery of small amount of electric current through the skin to extract the target molecules. This concept has received tremendous attention in the past decade; however, the technology still needs stringent validation for widespread implementation. Thus, in the present review, we aimed to elaborate the underlying mechanism of the reverse iontophoresis technique in the evaluation of blood glucose levels through skin, its unique features and its advancements towards commercialisation, the challenges faced, additional applications and the future prospects. The review also updates about the other non-invasive glucose monitoring techniques in comparison to reverse iontophoresis.