Multivesicular liposome sustained delivery of a novel synthetic electropositive GnRH antagonist LXT-101: preparation and in vitro evaluation

Using a simple method to determine the interaction between peptide and lipid bilayer and then deciding how to modify formulation from classic DepoFoam technology, multivesicular liposome of LXT-101 (DepoLXT-101) was prepared and characterized by in vitro evaluation.  The electrostatic adsorption between peptide and lipid bilayer was observed by zeta potential and fluorescence spectrum.  Anionic surfactants were added to stable the multiple emulsion and minimize the opposite effects resulted from drug.  Encapsulation   efficiency was determined by RP-HPLC.  Morphology, particle size of DepoLXT-101 particles were characterized and their in vitro release was studied in sodium chloride solution.  The DepoLXT-101 particles were prepared with good encapsulation efficiency, narrow size distribution and multivesicular construction.  Over 95% of the DepoLXT-101 particles were in a size range of 5−20 μm.  The in vitro assay in sodium chloride solution at   37 ℃ showed that 70%−90% of the peptide was released from particles slowly over 11 days.  Multivesicular liposome sustained delivery of synthetic cationic peptides could be successfully prepared by the method.