Preparation of berberine hydrochloride long-circulating liposomes by ionophore A23187-mediated ZnSO4 gradient method

The aim of the study was to prepare berberine hydrochloride long-circulating liposomes and optimize the formulation and process parameters, and investigate the influence of different factors on the encapsulation efficiency. Berberine hydrochloride liposomes were prepared in response to a transmembrane ion gradient that was established by ionophore A23187. Free and liposomal drug were separated by cation exchange resin, and then the amount of intraliposomal berberine hydrochloride was determined by UV spectrophotometry. The optimized encapsulation efficiency of berberine hydrochloride liposomes was 94.3% ± 2.1% when the drug-to-lipid ratio was 1:20, and the mean diameter was 146.9 nm ± 3.2 nm. As a result, the ionophore A23187-mediated ZnSO4 gradient method was suitable for the preparation of berberine hydrochloride liposomes that we could get the desired encapsulation efficiency and drug loading.