HPLC quantification of doxorubicin in plasma and tissues of rats treated with doxorubicin loaded poly(alkylcyanoacrylate) nanoparticles.

The long-term clinical use of doxorubicin (Dox), one of the most important anticancer agent in use, is limited by dose-related acute cardiotoxicity, myelo-suppression and multidrug resistance developed by cancer cells. To improve the antitumor efficacy and reduce the toxicity of Dox, many drug delivery systems have been developed, including poly(alkylcyanoacrylate) (PACA) nanoparticles. A new formulation of PACA nanoparticles with potential stealth properties were prepared by redox radical emulsion polymerization and associated to Dox in our laboratory. To comparatively investigate the pharmacokinetics and the biodistribution of different formulations of Dox associated PACA nanoparticles, a simple and rapid high performance liquid chromatographic method (HPLC) was developed for the quantification of Dox in plasma and tissues of rats treated with Dox loaded PACA nanoparticle (Dox-PACA). Dox was eluted at 4.4 min and it was well separated from its main metabolites doxorubicinol (Doxl) and doxorubicinon (Doxon) and idarubicin (Ida) used as internal standard (IS). Extraction of Dox from biological media was achieved by liquid-liquid extraction. The recovery of total Dox (i.e. free Dox and Dox associated with nanoparticles) from plasma and tissues (liver, spleen and heart) spiked with Dox-PACA were 71 and 78% for 0.05 and 1 μg/mL in rat plasma, respectively, and 73% and 80% for 0.5 and 10 μg/g in tissues, respectively. The method is linear from 0.05 to 1.5 μg/mL of Dox in plasma. The limit of detection of the method is 0.5 ng of Dox per injection (50 μL). The between-day and within-day precisions of the method were 97.1-102.9% and 97.3-101.7% for concentrations ranging from 0.05 to 1 μg/mL, respectively. Preliminary data suggested that this method can be applied to determine the pharmacokinetic and biodistribution of Dox associated with PACA nanoparticles after intravenous administration to rats.