Comparative study on physicochemical properties of three kinds of novel preparations of alprostadil

HEI Yu; MA Shuang; LI Xiao-nan; ZENG Wei; WANG Gui-ling; XIE Ying

Abstract：Objective:To systematically compare the structures and physicochemical properties of three kinds of novel preparations of alprostadil,including lipid emulsion (LE),lipid nanospheres (LN),and dry emulsion (DE).Methods:Morphological characteristics was observed under transmission electron microscope (TEM),size distribution and poly-dispersity index (PDI) were determined with laser dynamic scattering instrument,and the effects of pH,ion strength and serum on the stabilities of the three preparations were studied.The structures and components were determined with FT-IR spectrum and differential scanning calorimetry (DSC) technique.The entrapment efficiency (ee％) of alprostadil in the three preparations were determined by super-filtration method.Results:LE had membrane structure and clear membrane boundary,and the particle size was around 150 nm.LN presented the pebble shape structure with particle size of 200 nm.The re-dissolution of DE were granular without membrane structure.Under the influences of different ionic strengths,pH values and serum,the stability of the preparations was as follows:LE ＞ LN ＞ DE.The formulation composition of LE was similar to that of LN,but the content was different.However,DE was obviously different from LE and LN.The entrapment efficiencies of LE,LN and DE were (92.06 ± 1.49) ％,(83.08 ± 6.05) ％,(81.99-± 6.90) ％,respectively.Conclusion:There are similarities and differences in the structures and physicochemical properties among the three kinds of novel alprostadil preparations.LE and LN,which have similar structures,are significantly different from DE.Compared with LN,LE possesses better stability and higher encapsulation efficiency.