Abstract
Hyaluronidase is clinically used in treating many skin diseases due to its good permeability-promoting effect, which may motivate the diffusion and absorption of drugs. To verify the penetration osmotic effect of hyaluronidase in microneedles, 55 nm-size curcumin nanocrystals were fabricated and loaded into microneedles containing hyaluronidase in the tip. Microneedles with bullet shape and backing layer of 20% PVA + 20% PVP K30 (w/v) showed excellent performance. The microneedles were able to pierce the skin effectively with a skin insert rate of 90% and demonstrated good mechanical strength. In the in vitro permeation assay, with the increase of hyaluronidase concentration at the tip of the needle, the cumulative release of curcumin increased, as well as the skin retention decreased. In addition, compared with the microneedles without hyaluronidase, the microneedles containing hyaluronidase in the tip exhibited a larger drug diffusion area and deeper diffusion depth. In conclusion, hyaluronidase could effectively promote the transdermal diffusion and absorption of the drug.