Preparation and in vitro characterization of octreotide-targeting doxorubicin liposome

The aim of this study was to develop the preparation method of octreotide-targeting doxorubicin liposome.First,doxorubicin plain liposome (P-L) was prepared by ethanol injection and ammonium sulfate gradient loading,and optimized by single-factor design regarding formulation and pharmaceutical process.Then octreotide-targeting liposome (Oct-L) was obtained by post-inserting Octreotide-PEG₄₀₀₀-HSPE into prepared liposome.Sephadex G-50 column separation and zetasizer were used to evaluate drug entrapment efficiency,size distribution and storage stability; transmission electron microscopy was used to evaluate its surface morphology and dialysis method was used to investigate the drug release profile.It was shown that octreotide-targeting liposome had a mean size of 100 nm and a drug entrapment efficiency of 100%.The liposome particle was round and only 20% of entrapped doxorubicin was released after 48h incubation in pH 7.4 PBS under 37 °C.Compared to plain doxorubicin liposome,octreotide-targeting doxorubicin liposome showed stronger cytotoxicity and higher cellular uptake on NCI H-446 expressing somatostatin receptor.Therefore,ethanol injection,ammonium sulfate gradient loading and post-insertion method can be utilized to construct doxorubicin liposome and to achieve octreotide targeting modification.