Determination of docetaxel in rat plasma and its application in the comparative pharmacokinetics of Taxotere and SID530, a novel docetaxel formulation with hydroxypropyl-β-cyclodextrin

Effect of the Phragmitis Rhizoma Aqueous Extract on the Pharmacokinetics of Docetaxel in Rats

BACKGROUND

Traditionally, Phragmitis rhizoma has been prescribed to relive a fever, vomiting, dysuria, and constipation, and to promote secretion of fluids. In addition, recent studies have reported its efficacy as a diuretic and antiemetic. Our previous study demonstrated that the Phragmitis rhizoma aqueous extract (EPR) ameliorates docetaxel (DTX)-induced myelotoxicity.

AIM AND OBJECTIVE

This study was aimed to investigate the effects of EPR on the pharmacokinetics of DTX in Sprague-Dawley rats.

MATERIALS AND METHODS

The animals received an intravenous injection of DTX (5 mg/kg) with or without oral EPR (100 mg/kg) pretreatment for 1 or 6 days. The pharmacokinetics of plasma DTX was analyzed using an ultra-performance liquid chromatography-tandem mass spectrometry system, and pharmacokinetic parameters were estimated via noncompartmental analysis.

RESULTS

Relative to the control group (DTX alone), EPR pretreatment did not affect significantly the overall profiles of plasma DTX levels. Consecutively pretreated EPR for 6 days slightly altered AUC0-t and Cmax of DTX by 122 and 145.9%, respectively, but these data did not reach the threshold of statistical significance (p > 0.05).

CONCLUSION

These results indicate that DTX exposure may not be affected by EPR treatment at the dose level used in this study, suggesting that oral EPR can be used safely when taken with intravenously injected DTX. However, further studies under the stringent conditions are needed when chronic treatment of EPR and anticancer drug.

Pluronic P105/F127 mixed micelles for the delivery of docetaxel against Taxol-resistant non-small cell lung cancer: optimization and in vitro, in vivo evaluation

The aim of this work was to establish a novel polymeric mixed micelle composed of Pluronic P105 and F127 copolymers loaded with the poorly soluble antitumor drug docetaxel (DTX) against Taxol-resistant non-small cell lung cancer. A central composite design was utilized to optimize the preparation process, helping to improve drug solubilization efficiency and micelle stability. Prepared by a thin-film hydration method, the average size of the optimized mixed micelle was 23 nm, with a 92.40% encapsulation ratio and a 1.81% drug-loading efficiency. The optimized formulation showed high storage stability in lyophilized form, with 95.7% of the drug content remaining after 6 months’ storage at 4°C. The in vitro cytotoxicity assay showed that the IC50 values for Taxotere^® and mixed micelles were similar for A549, while on A549/Taxol cell lines, DTX-loaded P105/F127 mixed micelles showed a superior hypersensitizing effect; their IC50 value (0.059 μg/mL) was greatly reduced compared to those of Taxotere injections (0.593 μg/mL). The in vivo pharmacokinetic study showed that the mixed-micelle formulation achieved a 1.85-fold longer mean residence time in circulation and a 3.82-fold larger area under the plasma concentration-time curve than Taxotere. In addition, therapeutic improvement of mixed micelles in vivo against A549/Taxol was obtained. The tumor inhibition rate of the micelles was 69.05%, versus 34.43% for Taxotere (P < 0.01). Therefore, it could be concluded from the results that DTX-loaded P105/F127 mixed micelles might serve as a potential antitumor drug delivery system to overcome multidrug resistance in lung cancer.