Nanostructures from alkyl vitamin C derivatives (ASCn): Properties and potential platform for drug delivery

Alkyl vitamin C derivatives (ASCn) combine in their structure a lipophilic and a hydrophilic moiety and exhibit properties of typical surfactant molecules. Self-assembly properties of ASCn depend on the length of n-alkyl fatty chain. ASCn start to aggregate at temperatures (CMT, Krafft point) in which the solubility reaches the critical micellar concentration (CMC). Above this temperature, ASCn can aggregate in micelles or gel phase, depending of alkyl side chain. Upon cooling, for less soluble derivatives (ASC12, ASC14 and ASC16) liquid-crystal structures named coagels are obtained. They are able to solubilized insoluble and unstable drugs, protect them from any possible aggressive environment and promote their permeation through skin. Besides, the rheological properties of the coagels would be adequate for topical administration of pharmaceutical. These systems possess very interesting properties making ASCn coagels promising pharmaceutical platforms for drug delivery. Results from investigations about all these properties are described and analyzed. Also, the perspectives of these systems as drug delivery systems are discussed.