Berberine-loaded solid proliposomes prepared using solution enhanced dispersion by supercritical CO2: Sustained release and bioavailability enhancement

In present study, berberine proliposomes (ber-PL) of powder state that can form liposomal structure via self-assemble in water was prepared using solution enhanced dispersion by supercritical CO2 (SEDS) to improve the oral bioavailability of berberine. Several important parameters were optimized using Box-Behnken design to get ber-PL with high entrapment efficacy (EE) of 90.3% +/- 4.9%. Physicochemical characterization showed the optimum ber-PL was amorphous spherical nanoparticles and could form uniform liposomes around 80 nm easily via hydration. EE was closely related to the particle morphology of ber-PL. In vitro drug release study displayed a sustained release profile, and the drug released faster in neutral condition than acid medium. The oral bioavailability for ber-PL was 22.47 times greater than raw berberine, and the mean residence time of berberine in plasma was extended from 6.82 +/- 2.99 to 10.83 +/- 2.01 h as well. The proliposome formulated using SEDS is a favorable strategy to improve the bioavailability of berberine.