Liposomes modified with borneol-containing surfactants for transdermal delivery of hydrophilic substrates

New surfactants based on borneol (BA-n) with various alkyl tail lengths (n = 10, 12) were synthesized and studied as permeation enhancers for transdermal delivery of hydrophilic substrates. New modified liposomes based on BA-n and the lipid phosphatidylcholine (PC) were obtained and characterized by various physicochemical methods. The composition of liposomes was optimized by varying the surfactant/lipid molar ratio. It was shown that modification of PC liposomes with borneol surfactants increases their stability over time. The modified liposomes were loaded with a hydrophilic probe, rhodamine B. The release of the substrate from the resulting systems was monitored in vitro. The liposomal forms with the encapsulated probe were evaluated as potential systems for transdermal delivery using Franz cells. The application of the modified liposomes was found to enhance the transdermal diffusion.