Transdermal Delivery of Nanoparticles Using Microneedles and Iontophoresis (P13-001-19)

Microneedles (MN) and iontophoresis are innovative approaches for transdermal delivery of drugs and bioactive compounds. They can make the treatment tolerable, safe, and convenient. Nanoparticles (NPs) can enhance solubility, stability and prolonged release of many drugs and bioactive compounds and deliver them to specific cells. In the present study, we determined the delivery efficacy of dye-loaded lipid NPs using MN, iontophoresis and their combination, in an in vitro skin permeation study. We have synthesized lipid NPs carrying 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N- (lissamine rhodamine B sulfonyl (Rhod PE) dye. MN derma skin rollers with different needle length were used for microneedling. Iontophoresis was applied using a patch and a constant-current power supply. The abdominal skin of porcine was initially treated by the MN derma roller and then topically treated with NP solutions. In the combined treatment (MN and iontophoresis); the NP solution was loaded into an iontophoretic patch and applied on the MN-treated skin for 2, 4, 6, 12 and 24 hours at 0.2 mA/cm². Non-treated skin (no MN or iontophoresis) was used as a control group. Fluorescent dye intensity in different skin layers were examined using a fluorescence microscopy. The penetration of fluorescent dye through the skin layers was increased and reached to the subcutaneous adipose tissue following increment of MN length (1.5 mm > 1 mm > 0.5 mm), time and combined treatments. Combination of MN and iontophoresis resulted in increased dye intensity in the dermis and subcutaneous adipose tissue over time. The combination of MN and iontophoresis can enhance subcutaneous delivery of drugs and bioactive compounds, along with enhanced efficacy and patient compliance, and reduced toxicity. We envision that combination of MN and iontophoresis could offer a clinical superiority over traditional, invasive injections for combating diseases and disorders. NIH (Grant R15AT008733).