Berberine (BRB) is a natural isoquinoline alkaloid, used for many therapeutic activities by the Traditional Chinese Medicine, from the ancient times. Escin (ESN) is a mixture of triterpenic saponins that exhibits anti-inflammatory properties [1] and it was selected for both structural and functional activity [2]. Different liposomes, loaded with BRB HCl, were prepared according to the lipid film hydration method. All liposomes showed optimal sizes, low polydispersity and spherical shape. The dialysis bag method, followed by HPLC-DAD analysis, was used to define the Encapsulation Efficiency (EE%) and to investigate the in vitrorelease of BRB HCl and ESN. EE% were about 67% for the first one and 94% for the second one. Concerning the kinetic release, it was found a maximum delivery around 75% and 25% respectively, within 24 h. Liposomes had chemical-physical stability, until a month storage period, at 4°C. Deformation capability of the vesicles was evaluated by extrusion. Then, the formulations were tested by a system of parallel artificial membranes (PAMPA), miming the stratum corneumand the ex vivopermeation assay was made on rabbit ear skin, using vertical diffusion Franz cells .Passive transport through PAMPA and skin permeability were higher for BRB HCl loaded in ESN-based liposomes than BRB HCl loaded in the conventional liposomes formulated with phosphatidylcholine and cholesterol, or respect to the free molecule. In conclusion, ESN-based liposomes loaded with BRB HCl are deformable vesicles, able to cross the skin until the deepest layers of epidermis and suitable for dermatological applications to achieve a therapeutic synergy.
References:
[1] Xin W, et al. Escin exerts synergistic anti-inflammatory effects with low doses of glucocorticoids in vivo and in vitro. Phytomedicine 2011 ; 18 : 272-277.
[2] Tsibranska S, et al. Self-Assembly of Escin Molecules at the Air–Water Interface as Studied by Molecular Dynamics. Langmuir 2017 ; 33 : 8330-8341.