The purpose of this study was to investigate and compare the pharmacokinetic behavior and tissue distribution of paclitaxel, delivered as commercial preparation Taxol or through Span 40 niosomes, after intravenous injection to rats.Paclitaxel-loaded Span 40 niosomes were prepared using the thin-film method. An HPLC method was developed and validated for paclitaxel determination in rat plasma and tissues.The area under the curve value of the niosome-recipient group (3.22 ± 0.255 μg h/mL) was significantly higher compared to that of the Taxol group (0.725 ± 0.163 μg h/mL). The mean residence time and the elimination half-life of paclitaxel were 1.66 ± 0.133 h and 1.15 ± 0.085 h for Taxol administration, respectively. The elimination half-life (7.63 ± 0.380 h) and the mean residence time (11.0 ± 0.6 h) of paclitaxel were significantly increased, and a pronounced delay was observed in general excretion of paclitaxel from plasma (0.0925 ± 0.00490 h(-1)) after niosomal administration. The spleen was the main tissue that accumulated paclitaxel from both niosomes and Taxol.The findings of this study show that niosomal formulation might be a useful drug delivery system for intravenous administration of paclitaxel.
