Rapid Intradermal Delivery of Liquid Formulations Using a Hollow Microstructured Array

Purpose The 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. Methods 3M'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. Results Up 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. Conclusions 3M'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.