Development and Validation of a Method for Determination of Encapsulation Efficiency of CPT-11/DSPE-mPEG2000 Nanoparticles

Herein we report development and validation of the method for evaluating the encapsulation efficiency of a micelle-based nanosystem composed of irinotecan hydrochloride (CPT-11) and an amphiphilic molecule DSPEmPEG2000. The results showed that the centrifugation method can be used for separation of free drug, a critical step in measuring encapsulation efficiency, and the EE of three batches of CPT-11/DSPE-mPEG2000 micelles was 90.0% ± 1.0%. The results also indicated that the conditions used in the process have to be optimized to acquire reliable data.