The design of manufacturing process of mold for producing polymeric dissolving microneedles

Introduction. Polymeric dissolving microneedles are promising way for drug delivery especially for vaccine delivery. It is an important task to create a scalable way of manufacture of dissolving polymeric microneedles. First step in this process is to create an easy and cheap way of producing negative master-molds for microneedles. Objective. To develop the laser production technology of negative master-mold for dissolving polymeric microneedles. Material and methods. Possibility of using different polymer plates (polydimethylsiloxane, polycarbonate, polystyrene, polypropylene, polymethyl methacrylate and polyethylene terephthalate) for producing negative microneedle molds and material’s surface free energy were examined. The modes of laser ablation of polymer and ways of its control were investigated. Pullulan dissolving microneedles were produced by using designed molds and examined by optical microscopy. Results. Polyethylene terephthalate was chosen as the optimal polymer for producing negative microneedle mold because it leads to producing symmetrical microneedles with desired geometry. Also the 2-step laser technology for the fabrication of polymeric microneedle molds and methods of mold’s quality control during manufacture was designed in this study. The technological scheme of polyethylene terephthalate microneedle mold’s manufacture was proposed in results of this study. The variety of manufacturing defects of polyethylene terephthalate microneedle mold and it’s causes were summarized. Conclusion. The designed laser technology of producing negative microneedle molds in combination with right mold’s material (polyethylene terephthalate) can guarantee robust producing of dissolving polymeric microneedles and gives a possibility to scale it up.