Comparative Study on Pharmacokinetics and Tissue Distribution of Two Paclitaxel Injection Formulations in Tumor-bearing Mice

OBJECTIVE To compare the pharmacokinetic characteristics of paclitaxel formulated in Cremophor ethanol (Taxol) with that formulated as an albumin-bound nanoparticle (ABI) in tumor-bearing mice. METHODS ABI and Taxol were intravenously administrated with the same dosage of paclitaxel to tumor-bearing BALB/c mice, and then pharmacokinetic profiles of paclitaxel were investigated by determining drug concentration in plasma and tumor, and major tissues including heart, liver, spleen, lung, and kidney with HPLC. RESULTS The group administrated with ABI showed a significantly lower AUC of paclitaxel in plasma and greater Vd and CL. However, the AUC of paclitaxel in tumor was 23.3% higher for ABI than that for Taxol (P<0.05). The two groups had similar distribution profiles in tissues except that paclitaxel concentration in lung was much higher in the group of Taxol. CONCLUSION Compared with the conventional paclitaxel injection formulated in Cremophor ethanol, albumin-bound nanoparticle of paclitaxel showed better pharmacokinetic and tumor-targeting properties.