PurposeThe purpose of this work is to demonstrate rapid intradermal delivery of up to 1.5 mL of formulation using a hollow microneedle delivery device designed for self-application.Methods3M’s hollow Microstructured Transdermal System (hMTS) was applied to domestic swine to demonstrate delivery of a variety of formulations including small molecule salts and proteins. Blood samples were collected after delivery and analyzed via HPLC or ELISA to provide a PK profile for the delivered drug. Site evaluations were conducted post delivery to determine skin tolerability.ResultsUp to 1.5 mL of formulation was infused into swine at a max rate of approximately 0.25 mL/min. A red blotch, the size of the hMTS array, was observed immediately after patch removal, but had faded so as to be almost indistinguishable 10 min post-patch removal. One-mL deliveries of commercial formulations of naloxone hydrochloride and human growth hormone and a formulation of equine anti-tetanus toxin were completed in swine. With few notable differences, the resulting PK profiles were similar to those achieved following subcutaneous injection of these formulations.Conclusions3M’s hMTS can provide rapid, intradermal delivery of 300–1,500 µL of liquid formulations of small molecules salts and proteins, compounds not typically compatible with passive transdermal delivery.

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Dielectric elastomer actuators (DEAs), unlike traditional actuators, are lightweight, soft, smart materials that are proving to be attractive in a broad range of potential applications such as robotic arms, artificial muscles, medical devices, stretchable sensors, grippers, loudspeakers, and automotive lightweighting. Though they have been known and studied for decades, their use is not widespead in part due to a number of practical implementation difficulties including the need for and handling of thin dielectric layers to reduce operating voltage, strechable and stackable electrodes that don’t overly degrade performance, and poor longevity due to electrical breakdown contributed by potential flaws in the thin film and material inclusions/irregularities. This paper investigates the construction of DEA multi-layer and single-layer articles, exploring the effect of non-negligible elastomer-based electrodes with various dielectric/electrode layer thickness ratios as well as the influence of stacked dielectric layers on breakdown voltage. A balance between actuator performance and the level of required voltage for operation is shown given a set of assumptions. Furthermore, the influence of stacked dielectric layers on breakdown voltage is demonstrated, confirming previous results performed with polyvinylidene fluoride (PVDF).