Abstract

Presented in this abstract is the reconsideration of various important factors in the measurement of the drug loading content (DLC) and drug loading efficiency (DLE) based on an ‘instant’ biocompatible and biodegradable polymer vesicle which can be directly ‘dissolved’ in water, with a focus on the study of the time for removing the free drug. A detailed dialysis methodology to remove the free drug before starting the drug release experiment was established. Specifically, the water outside the dialysis tube was renewed every 30 min at 20 °C and the magnetic stirring rate was set at 190 rpm. We found that the time for efficiently removing the free drug was 7.5, 4.5 and 4 h when the drug feed was 1.0, 3.0 and 5.0 mg, respectively. This time is important for the subsequent calculation of DLC and DLE. When the DOX feeds were 1.0, 3.0 and 5.0 mg, the DLCs were 0.96%, 6.51% and 9.76%, respectively. The corresponding DLEs were calculated as 9.8%, 22% and 20%, respectively. The hydrolysis of the PCL membrane in acidic condition leads to a faster DOX release rate (55%) when compared to 40% in neutral condition after 24 h. The great significance of using a correct calibration curve in dealing with UV absorbance data was emphasized. The above findings provide new insights regarding the determination of more accurate DLC and DLE by dialysis method [1].

Keywords: Block copolymer vesicles, Drug delivery, Doxorubicin, Dialysis  

文章链接：Journal of Controlled Release 2013, 172, e41.