Development and validation of a high performance liquid chromatography quantification method of levo-tetrahydropalmatine and its metabolites in plasma and brain tissues: application to a pharmacokinetic study.
Levo-tetrahydropalmatine (l-THP) is an alkaloid isolated from Chinese medicinal herbs of the Corydalis and Stephania genera. It has been used in China for more than 40 years mainly as an analgesic with sedative/hypnotic effects. Despite its extensive use, its metabolism has not been quantitatively studied, nor there a sensitive reliable bioanalytical method for its quantification simultaneously with its metabolites. As such, the objective of this study was to develop and validate a sensitive and selective HPLC method for simultaneous quantification of l-THP and its desmethyl metabolites l-corydalmine (l-CD) and l-corypalmine (l-CP) in rat plasma and brain tissues. Rat plasma and brain samples were processed by liquid-liquid extraction using ethyl acetate. Chromatographic separation was achieved on a reversed-phase Symmetry® C18column (4.6 × 150 mm, 5 μm) at 25°C. The mobile phase consisted of acetonitrile-methanol-10 mm ammonium phosphate (pH 3) (10:30:60, v/v) and was used at a flow rate of 0.8 mL/min. The column eluent was monitored at excitation and emission wavelengths of 230 and 315 nm, respectively. The calibration curves were linear over the concentration range of 1-10,000 ng/mL. The intra- and interday reproducibility studies demonstrated accuracy and precision within the acceptance criteria of bioanalytical guidelines. The validated HPLC method was successfully applied to analyze samples from a pharmacokinetic study of l-THP in rats. Taken together, the developed method can be applied for bioanalysis of l-THP and its metabolites in rodents and potentially can be transferred for bioanalysis of human samples.
Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, USA.|Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Misr International University, Cairo, Egypt.
Inas A
IA
Abdallah
Center for Substance Abuse Research and Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA.
Peng
P
Huang
Bio-Organic and Natural Products Laboratory, McLean Hospital, Harvard Medical School, Belmont, Massachusetts, USA.
Jing
J
Liu
Bio-Organic and Natural Products Laboratory, McLean Hospital, Harvard Medical School, Belmont, Massachusetts, USA.
David Y
DY
Lee
Center for Substance Abuse Research and Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA.
Lee-Yuan
LY
Liu-Chen
Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, USA.|Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Helwan University, Cairo, Egypt.
Hazem E
HE
Hassan
D000818:Animals; D001599:Berberine / Q000031:analogs & derivatives / Q000032:analysis / Q000097:blood; D001600:Berberine Alkaloids / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D006576:Heterocyclic Compounds, 4 or More Rings / Q000032:analysis / Q000097:blood; D059625:Liquid-Liquid Extraction; D008297:Male; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity
D001600:Berberine Alkaloids; D006576:Heterocyclic Compounds, 4 or More Rings; D001599:Berberine; C471057:corypalmine; C058198:corydalmine; C014215:tetrahydropalmatine
HPLC; l-CD; l-CP; l-THP; pharmacokinetic study