Technique to encapsulate a low molecular weight hydrophilic drug in biodegradable polymer particles in a liquid-liquid system

► Preparation of PLGA particles encapsulated hydrophilic drug of a low molecular weight was tried. ► PLGA particles with 8.0% loading efficiency were prepared from w/(o1 + o2)/o3 emulsion. ► To improve drug loading efficiency, preparation technique of particular emulsion was suggested. ► By applied particular emulsion, drug loading efficiency of resulting particles was improved. ► The prepared particle from particular emulsion was spherical and smooth surfaces.