Design and optimization of a microneedle with skin insertion analysis for transdermal drug delivery applications

Effectively delivering the drugs through the human skin with less pain and reducing the chance of tissue damage are the main attributes of a microneedle. This paper presents an out-of-plane single silicon carbide (SiC) microneedle having six lumens for drug passing. The total length of the proposed microneedle is about 350 mu m with the inner diameter of 30 mu m and the outer diameter of 52 mu m. COMSOL multiphysics software is used to analyze the performances of the proposed microneedle. The simulated durability of the microneedle is investigated by applying the axial load which generates less stress and deformation. Then, an optimized microneedle tip is designed which reduce pain during insertion. The flow analyses of various viscosity based fluids inside the microneedle are also investigated. Among the selected fluids, the flow of the ibuprofen shows a lowest velocity distribution because of its high dynamic viscosity. The maximum flow rates of ibuprofen are found as 0.01 mu L/ min and 0.9 mu L/min while the inlet pressure are 10 kPa and 100 kPa respectively. On the contrary, a low viscosity fluid such as water provides flow rates of 45.24 mu L/min and 433.49 mu L/min at same inlet pressures. To verify the performances of our proposed microneedle, a skin model consisting three layers of stratum corneum, epidermis and dermis is designed. Simulation results confirm that the proposed microneedle successfully penetrated the skin model and remains unbroken.