Hydroxypropyl methylcellulose hydrogel of berberine chloride-loaded escinosomes: Dermal absorption and biocompatibility.

Aim of this work was to prepare and characterize new nanocarrier-loaded hydrogel formulations for topical application, using hydroxypropyl methylcellulose (HMPC) and special nanovesicles, the escinosomes. The combination of the two technological strategies, nanocarriers and hydrogels, was selected to circumvent some drawbacks of nanovesicles and develop stable and efficient skin-delivery platforms. HPMC is a derivative of cellulose with a wide range of physicochemical properties, forming suitable hydrogel for dermatological applications. Escinosomes, made of escin (ESN), a natural bioactive saponin, plus phosphatidylcholine, were loaded with berberine chloride (BRB), a bioactive natural product, and were entrapped in the polymeric matrix of HPMC. Release and permeation properties of aqueous ESN and BRB dispersions, escinosomes were compared with the corresponding hydrogels. Viscosity measurements evidenced their suitability for topical applications. In vitro permeation experiments showed a higher residence time of the HPMC-hydrogel. Thus, the new escinosome HPMC-hydrogel formulations combine the advantages of a modified release and increased transdermal permeability (escinosome components), with better viscosity properties (polysaccharide matrix). In addition, the developed HPMC-hydrogels also had a very good safety profile and skin biocompatibility studies showed no potentially hazardous skin irritation. Finally, the developed escinosome HMPC-hydrogel formulations were very stable with appropriate mechanical properties.