5-Fluorouracil-Loaded Hyaluronic Acid-Coated Niosomal Vesicles: Fabrication and Ex Vivo Evaluation for Skin Drug Delivery.

5-Fluorouracil (5-FU) is one of the most potent drugs against solid tumors. However, its parenteral administration is associated with systemic toxicity, while its topical application has limited percutaneous absorption. To overcome these limitations, the current study undertakes the formulation of 5-FU as niosomal vesicles that were coated with hyaluronic acid to improve its targeting efficiency for cancer cells. The niosomes were prepared by the thin-film hydration method using cholesterol as physiological lipid and nonionic surfactants (Tween 80 and Span 80) in the ratio of 1:1. The niosomal vesicles were characterized for their size, size distribution, viscosity, surface tension, density, and drug entrapment efficiency. The vesicles were within the particle size range of 337-478 nm with relatively homogeneous particle size distribution (PDI ≤ 0.5). The ζ-potential and drug entrapment efficiency of coated formulations (F2 and F4) were comparatively higher than corresponding noncoated formulations (F1 and F3). The release behavior of 5-FU from niosomal vesicles using a dialysis membrane depicts that initial burst drug release was higher for F1 and F3 due to their smaller particle size in comparison to their coated counterparts. However, the release was more controlled for F4 due to the larger particle size, higher viscosity, and entrapped fraction of the formulation. The permeation of the drug through the rat's skin was comparatively higher in the case of noncoated formulations than their coated counterparts (