Quantification of Doxorubicin and metabolites in rat plasma and small volume tissue samples by liquid chromatography/electrospray tandem mass spectroscopy.

The anthracycline Doxorubicin (DXR) is used widely for the treatment of human malignancies, and drug delivery technologies are under investigation to enhance antitumor selectivity and effectiveness. A liquid chromatography-tandem mass spectroscopy (LC-MS/MS) method was developed to identify and quantify DXR and key metabolites in small-volume biological samples. The assay was linear over the therapeutically relevant concentration range (0.125-10,000 nM); in brain tissue, the lower limit of quantification was 0.247 nM and the sensitivity was 1.4 pg. The ability to quantify DXR and detect metabolite formation may provide insight into the toxicity and bioavailability of drug incorporated into carriers such as liposomes.