Simultaneous analysis of liposomal doxorubicin and doxorubicin using capillary electrophoresis and laser induced fluorescence

A method based on a capillary electrophoresis with laser induced fluorescence detection was developed and validated for simultaneous separation of doxorubicin (DOX) and liposomal encapsulated DOX. The separation was accomplished using a fused silica capillary (60 cm in total length, 75 μm I.D.) and potassium phosphate buffer [12.5 mM, pH 7.4] as the running buffer. The effect of sample preparation conditions on maintaining liposomal integrity was also investigated. The limit of detection for DOX was 0.1 μg/ml and the precision and accuracy of CE/LIF method was within the ranges of FDA guidelines. The validated method was successfully used to quantify DOX in human plasma using a direct injection of a 4-fold dilution of spiked liposomal DOX in human plasma.