The tissue distribution and excretion of docetaxel submicron emulsion in rats were investigated.A high-performance liquid chromatog. (HPLC) with UV detection was developed to study the concentration of docetaxel in the biol. samples.Taking paclitaxel as an internal standard, 48 SD rats were randomly divided into 2 groups: test preparation and reference preparation, and each group was i.v. administered 75 mg·m-2 DTX.The rats were executed at 5, 30, 60 and 300 min, and tissues were taken in the same location to determine the content.The docetaxel submicron emulsion was widely distributed in the tissues of the body.The docetaxel concentration of the test group in the heart and lung was lower than that of the reference group, but higher than the reference group in the spleen.In the kidney, the docetaxel concentration of the test group increased quickly before 30 min and was higher than the reference group, and after that the concentration decreased even lower than the reference injection.The docetaxel concentrations of the 2 groups in other tissues and organs had no significant difference.The excretion of the parent drug in the urine and excrement amounted to 2% and 6% of the dose, resp.Submicron emulsion had no significant effect on docetaxel distribution, and the preparation was delivered effectively.In safety and pharmacodynamic evaluation, more attention should be paid to the alteration of toxicity and therapeutic effect after changing dosage forms.