Cloud-point extraction combined with HPLC for determination of larotaxel in rat plasma: a pharmacokinetic study of liposome formulation.
A simple and efficient method based on cloud-point extraction combined with high-performance liquid chromatography was developed and validated for the determination of larotaxel in rat plasma. Nonionic surfactant Triton X-114 was chosen as the extraction solvent. Variable parameters affecting the cloud-point extraction efficiency, for example the nature and concentration of surfactant, NaOH concentration, incubation temperature, and time were evaluated and optimized. Chromatographic separation was accomplished on a Diamonsil C(18)  column (150 mm × 4.6 mm, 5 μm) using a mobile phase consisting of acetonitrile and 0.1% phosphoric acid with pH 4.0 (60:40, v/v). The calibration curve showed good linearity over the range of 0.05-10 μg/mL. Under the optimum conditions, the method was shown to be reproducible and reliable with intraday precision below 5.7%, interday precision below 7.2%, accuracy within ±3.5%, and mean extraction recovery of 91.8-94.2%. The validated method was successfully applied to the pharmacokinetic study of larotaxel in rat plasma after a single intravenous administration of larotaxel injection and larotaxel-loaded liposome, respectively. The results indicated that the larotaxel-loaded liposome led to significant differences in pharmacokinetic profile.
Pharmacy Department, the Fourth Affiliated Hospital of China Medical University, Chongshan Eastern, Huanggu District, Shenyang, P R China. mahaiying2011@yahoo.com.cn
Haiying
H
Ma
Jian
J
You
Yafei
Y
Liu
D000818:Animals; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008081:Liposomes / Q000737:chemistry; D059625:Liquid-Liquid Extraction / Q000379:methods*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D043823:Taxoids / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics
D008081:Liposomes; D043823:Taxoids; C531079:larotaxel