Mixtures of hyaluronic acid and liposomes for drug delivery: Phase behavior, microstructure and mobility of liposomes

Publication date: 15 May 2017 Source:International Journal of Pharmaceutics, Volume 523, Issue 1 Author(s): Naila El Kechai, Sandrine Geiger, Arianna Fallacara, Ingrid Cañero Infante, Valérie Nicolas, Evelyne Ferrary, Nicolas Huang, Amélie Bochot, Florence Agnely Hyaluronic acid liposomal gels have previously demonstrated in vivo their great potential for drug delivery. Elucidating their phase behavior and structure would provide a better understanding of their use properties. This work evaluates the microstructure and the phase behavior of mixtures of hyaluronic acid (HA) and liposomes and their impact on the vesicle mobility. HA concentration and surface properties of liposomes (positively or negatively charged, neutral, with a polyethylene glycol corona) are varied while the liposome concentration remains constant. Below the entanglement concentration of HA (0.4%), the mixtures exhibit a depletion phase separation except for positively charged liposomes that interact with anionic HA through attractive electrostatic interactions. At high HA concentration, no macroscopic phase separation is observed, except a slight syneresis with cationic liposomes. The microstructure shows aggregates of liposomes homogeneously distributed into a HA network except for PEGylated liposomes, which seem to form bicontinuous interpenetrating networks. The diffusion of liposomes is controlled by HA concentration and their surface properties. Finally, PEGylated liposomes display the ...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research