Evaluation of the efficacy and safety of a new formulation-lipid emulsion-based PTX injection: Pharmacokinetics, tissue distributions and anticancer effect on human gastric cancer cells in vitro

Paclitaxel (PTX) is one of the most widely used chemotherapeutic agents. The commercial PTX formulation was based on Cremophor EL and ethanol owing to its poor aqueous solubility. However, Cremophor EL has been shown to cause toxic effects such as life-threatening anaphylaxis. In our study, we diluted PTX in a commercially available 20% (w/v) lipid emulsion (Lip-PTX) in order to avoid Cremophor EL. The purpose of this study was to evaluate the pharmacokinetics and tissue distributions between Lip-PTX and PTX injection. We also investigated the effects of Lip-PTX and PTX injection on human gastric cancer cells HGC-27 by MTT assay. The apoptosis was detected by flow cytometry with Annexin V/propidium iodide (PI) double staining. Furthermore, the safety such as acute toxicity was also assessed. The results showed that PTX in Sprague-Dawley rats administered Lip-PTX exhibited extended half-life, increased clearance (P < 0.05) and smaller area under the concentration-time curve compared with PTX injection and there was little significant difference in the distribution of PTX in Sprague-Dawley rats or tumor-bearing mice between Lip-PTX and PTX injection. The cells treated with Lip-PTX had a higher percentage of apoptosis and a higher G(2)/M phase ratio, which indicated that the anticancer effect of Lip-PTX was significantly better than that of PTX injection. Moreover, our study highlighted the safety of Lip-PTX. This study demonstrated the feasibility and potential advantages of Lip-PTX for clinical therapy.