Influence of probe-sonication process on drug entrapment efficiency of liposomes loaded with a hydrophobic drug

Since probe-sonication is commonly used to homogenize liposomal formulations, it is necessary to investigate its influence on drug entrapment efficiency (EE) of liposomes. In this study, ibuprofen-loaded liposomes (IBU-Lip) dispersion was prepared from ibuprofen (IBU), soy phosphatidylcholine (SPC) and cholesterol (Chol) by thin film hydration and probe-sonication process. The influences of sonication time and power on EE were studied. Also, the effects of SPC-to-Chol ratio and drug-to-lipid ratio on EE were demonstrated. The results indicated that increasing sonication time or decreasing drug-to-lipid ratio could increase EE. Additionally, EE first increased then decreased as sonication power increased or SPC-to-Chol ratio decreased.