To understand the quality, efficacy, and safety of liposomal drugs, it is necessary to develop a robust and accurate method for separation and quantification of free and liposome-associated drugs. Conventional methods involve separation of free and liposome-associated drug using solid phase extraction and quantification. This is a lengthy process and sometimes solid phase extraction induces drug leakage from the liposomes causing erroneous results. A capillary electrophoresis (CE) with UV-Vis detection method was developed for the simultaneous separation and quantification of free and liposome-associated drug using a doxorubicin-containing liposome formulation as the model drug. CE separates the free drug and liposomal drugs based on their electrophoretic mobility under electric field. In this study, liposomal drugs were diluted to the appropriate concentrations in running buffer before hydrodynamic sample injection with 30 mbar pressure for 10 s. Using a high-sensitivity detection cell, the doxorubicin CE detection sensitivity was enhanced about 10-fold compared to the conventional on-column UV-Vis detection with a 75 µm i.d. capillary column. The various analytical parameters including type of buffer, buffer concentration, buffer pH, and separation voltage have been investigated to explore the separation efficiency and reliability of quantification. The optimal separation of free doxorubicin from liposome-associated doxorubicin with minimal perturbation of liposomes was accomplished. The results obtained with the doxorubicin hydrochloride liposome injection demonstrate that CE with UV-Vis detection is a promising technique for the fast and simultaneous separation and quantification of free drug and liposome-associated drug formulations.

Simultaneous separation and quantification of free drug and liposome-associated drug by capillary electrophoresis with UV-Vis detection

254th National Meeting (2017)

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