Characterization of glycerol-silicone patches for wound healing applications with advanced image analysis

Silicone elastomers and adhesives with a dispersed glycerol phase within have been proven a very efficient and controlled transdermal delivery system (TDS). The core idea of this works is the characterization of glycerol-silicone patches. Thereby, having an understanding of the diffusion mechanisms which take place as soon as the patches are in contact with the human skin. The project will be carried out in two steps: an experimental part, which consists of data collection, and a modelling one, where the acquired data will represent an input to develop a digital design tool. In this thesis, just the first phase will be considered. At first, the analysis of the patch without any drug load or water absorption is performed, to study this system without the influence of any external mass transport phenomena. Afterwards, the two diffusion mechanisms are taken into account: in particular, the sweat from the skin is absorbed by the patch while at the same time, the active substance, together with some glycerol, diffuses into the skin. In particular, the investigation of the water diffusion process from the skin to the patch is performed. To study the system and to monitor water diffusion processes, a real-time particle imaging technology, oCelloScope® (ParticleTech ApS, Farum, Denmark) is used. It is a non-invasive measurement technology that allows obtaining online images thanks to a confocal microscope combined with a high-speed camera and afterwards processed using segmentation algorithms. From that, particle features are identified and will be used later on, to develop a hybrid machine learning assisted model. In conclusion, the first goal of this work is to study a novel type of transdermal delivery system (TDS) with a completely new image analysis technology, to retrieve meaningful data, that will be the starting point for the digital design of these glycerol-silicone patches.