An LC-MS method for determination of milbemycin oxime in dog plasma.
An HPLC-MS method has been developed and validated for the quantitative determination of milbemycin oxime (MBO) in dog plasma. The developed method has been then applied in in vivo clinical studies to obtain pharmacokinetics of MBO in blood after its oral administration. Samples were extracted using solid-phase extraction (SPE). Sample proteins were precipitated with acetonitrile (ACN) and sodium chloride (NaCl) and then diluted with methanol and water. Calibration standards were prepared by using plasma matrix and following the same SPE procedure. Chromatographic separation was performed on a Waters C18 packed column (3.5 μm particles diameter; 3 × 100 mm) with a C18 guard column (3.5 μm particles diameter; 3 × 20 mm). The mobile phase was an 85:15 (v/v) mixed solution of ACN and 5 mM ammonium acetate. The calibration curve was linear over a concentration range of 2.0-500 ng/mL with a limit of quantitation of 2.0 ng/mL. The oral administration of a pellet of 2.5 mg MBO produced blood concentrations ranging from 6.10 ± 0.92 to 78.81 ± 4.38 ng/mL within 6 h, with a terminal half-time of 11.66 ± 0.93 h. This study determined the suitability of the herein proposed method to investigate the pharmacokinetics of MBO after oral administration.
Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou 256600, China Shandong Lvdu Ante Veterinary Drug Industry Co., Ltd, Binzhou 256600, China qianqian19830125@163.com.
Qianqian
Q
Xu
College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China.
Jichang
J
Li
Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou 256600, China Shandong Lvdu Ante Veterinary Drug Industry Co., Ltd, Binzhou 256600, China.
Zhiqiang
Z
Shen
Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou 256600, China Shandong Lvdu Ante Veterinary Drug Industry Co., Ltd, Binzhou 256600, China.
Shijin
S
Guo
Department of Thoracic Surgery, Binzhou Medical College Hospital, Binzhou 256600, China.
Yubo
Y
Wang
Shandong Binzhou Animal Science and Veterinary Medicine Academy, Binzhou 256600, China Shandong Lvdu Ante Veterinary Drug Industry Co., Ltd, Binzhou 256600, China.
Feng
F
Li
D000284:Administration, Oral; D000818:Animals; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004285:Dogs; D004355:Drug Stability; D057230:Limit of Detection; D018942:Macrolides / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction
D018942:Macrolides; C078973:milbemycin oxime