Highly Water-Soluble Microneedle Patch for Short Wear Time and Rapid Drug Delivery

Treatment of acute medical conditions such as pain would benefit from rapid drug delivery and improved ease of administration of local anesthetics that currently have a slow onset of action by topical or oral administration and require expert administration by injection. To address this need, microneedle (MN) patches containing needlelike projections made from a polymer/drug matrix can be painlessly pressed into the skin for local or systemic drug delivery. To improve the speed and ease of drug delivery, we present a rapidly dissolving, highly water-soluble MN patch, which minimizes the wear time to 10 s to improve drug delivery in situations where rapid delivery with simplified administration is needed. MNs were made of polyvinylpyrrolidone (PVP), which is soluble in both water (enabling dissolution in the skin) and polar organic solvents (facilitating coformulation with lidocaine (L)). The addition of a highly water-soluble salt, sodium bicarbonate (NaB), to PVP/L MNs allowed for 60% faster MN dissolution in porcine skin ex vivo. Further addition of citric acid to generate effervescence upon reaction with NaB did not further decrease the MN dissolution time in the pig skin and led to poor shelf-life stability due to premature effervescence during storage. The PVP/L/NaB MNs delivered 23.8 ± 3.5 μg lidocaine to the skin ex vivo, well above the expected dose for local analgesic effect. Our highly water-soluble PVP/L/NaB MN design enables shorter wear time for faster delivery compared to the oral or topical route and easier administration compared to injection currently used for the delivery of drugs needing a rapid onset of action.