A Robust Chromatographic Method for Drug Release Profiling of Liposomal Doxorubicin HCl

Liposomes are excellent drug delivery vehicles for chemotherapeutics as they may change the pharmacokinetics of therapeutic compounds, resulting in altered tissues distribution, and in some cases, reduced cytotoxicity and enhanced distribution and efficacy of the active pharmaceutical ingredient (API) at target tissues. Drug release profiles of liposomal formulations are crucial to support equivalence evaluation and quality control in pre- and post-approval stages. We developed an automated chromatographic method for quantifying the drug release profile of liposomal formulations containing doxorubicin to overcome the shortcomings of currently available methods. The newly developed method employs nanoparticle exclusion chromatography (nPEC), using a monolithic silica column coated with polyvinylpyrrolidone to separate the released drug from liposomal encapsulated drug. We evaluated the effects of pH, temperature, and ammonium formate concentration on the drug release rate. The optimized release buffer consisting of 5 % sucrose, 20 mM l-histidine, and 200 mM ammonium formate was selected for the drug release profiling of five liposomal formulations at 47 °C. The drug release profiles of five liposomal doxorubicin formulations were similar. Our automated method requires very small amounts of the sample and provides release profiles with high sensitivity and accuracy. In addition, this method can be applied to other liposomal products to allow for simple, fast, and accurate analysis of in vitro drug release profiling.