Novel nanoliposomal delivery system for polydatin: preparation, characterization, and in vivo evaluation

BACKGROUND The objective of this study was to develop a novel polydatin (PLD)-loaded liposome system using the thin film hydration technique. METHODS The delivery system was characterized in terms of morphology, size, zeta potential, encapsulation efficiency, and in vitro release. In addition, a pharmacokinetic study was carried out in rats after oral administration of PLD-loaded liposomes in vivo. RESULTS Transmission electron microscopy revealed that the PLD-loaded liposomes had a homogeneous size and spherical shape. Dynamic light scattering showed that the PLD-loaded liposomes had a smaller size with a mean value of 80.2±3.7 nm and a polydispersity index of 0.12±0.06. The encapsulation efficiency of the prepared liposomes was 88.4%±3.7%. During the release process, liposome showed two distinct phases. The first was characterized by rapid release during the first 2 hours, which could be related to the release of the drug adsorbed on the surface of liposomes. In the second phase, the release rate slowed down, demonstrating a typical sustained and prolonged drug-release behavior. The release kinetic model for the PLD-loaded liposomes fitted well with the Weibull distribution equation. In vivo, relative oral bioavailability of the encapsulated PLD was 282.9%, ie, significantly enhanced (P<0.05) compared with the free drug. No histological changes occurred in the organs after administration of PLD-loaded liposomes. CONCLUSION PLD-loaded liposomes could significantly prolong the drug circulation time in vivo and increase the oral bioavailability of the drug.