Development and characterization of ivermectin loaded microneedle formulations using 3D printed molds

Rosacea is a chronic inflammatory disease that predominantly affects the midface area (cheeks, chin, nose, and forehead) and the eyes. Ivermectin is a broad-spectrum antiparasitic semi-synthetic molecule and has low solubility in water and poor ability to penetrate the skin. In this study, it was aimed to develop low-cost microneedle formulations with high standardization and achieve easy penetration into skin for enhanced drug permeability. Microneedle formulations containing ivermectin, polyvinylpyrrolidone (PVP) with different molecular weights, and PEG 400 were produced using polydimethylsiloxane (PDMS) molds fabricated matching 3D-printed master molds. To evaluate the mechanical strength of microneedles, the vertical hardness value (N) per needle was determined. in vitro drug release study, ivermectin release was examined in pH 7.4 buffer environment containing 1 % Tween 80 at 37 °C. The skin penetration properties of microneedles were evaluated in vitro and ex vivo penetration studies using fluorescence and scanning electron microscopy. F3 formulation containing 3 g of PVP K90 and 1 g of PVP K30 was selected for use in future studies due to its more suitable characteristics and ex vivo performance. As a result, highly standardized microneedles were obtained suitable for the use of ivermectin in various dermal diseases such as rosacea.