[Pharmacokinetics of (-)-clausenamide and its major metabolite 6-hydroxyl-clausenamide in beagle dogs by HPLC/MS].
To establish a sensitive and accurate method to study the pharmacokinetics of (-)-clausenamide [(-)-clau] and its major metabolite 6-hydroxyl-clausenamide (6-OH-clau) in the plasma of the Beagle dog.


METHODS
(-)-Clau was orally administered to six Beagle dogs at the dose of 30 mg x kg(-1), venous blood from front leg was sampled and plasma was separated for analysis. After extraction with ethyl acetate, the plasma samples were analyzed by HPLC/MS and the mobile phase was a mixture of methanol-water-acetic acid (60: 40: 0. 8) at the flow rate of 1.0 mL x min(-1). The API-ES positive ion SIM detection was carried out for the detection of both (-)-clau ([M + H] (+), m/z 298 ) and 6-OH-clau ([M + H - H2 O](+), m/z 296) with glipzide (glip) ([M + H](+), m/z 446) as internal standard. The pharmacokinetic parameters were calculated by 3P97 software.


RESULTS
There was good linear relationship ( r > 0. 999) between the SIM responses and the concentrations for (-)-clau and 6-OH-clau at the range from 1.0 to 200 ng x mL(-1) and 0.2 to 40.0 ng x mL(-1), respectively. The absolute recovery was greater than 85%. The plasma concentration-time curves of (-)-clau and 6-OH-clau were both best fitted to a two-compartment model. The C(max) of (-)-clau and 6-OH-clau were (21 +/- 10) ng x mL(-1) and (3.9 +/- 2.2) ng x mL(-1), T(max) were (0.8 +/- 0.5) h and (1.3 +/- 0.5) h, T 1/2 alpha were (0.9 +/- 0.6) hand (1.4 +/- 0.6) h, T 1/2 beta were (19 +/- 23) hand (13 +/- 12) h, AUC(0-24 h) were (69 +/- 14) h x ng x mL(-1) and (12 +/- 7) h x ng x mL(-1) respectively.


CONCLUSIONS
The established HPLC/MS method was sensitive and specific for the determination of (-)-clau. It was shown that the absorption and first phase elimination of (-)-clau were very quick in Beagle dogs, but the terminal elimination was very slow. The plasma concentration profile of its major metabolite 6-OH-clau was similar to (-)-clau and the AUC was relatively small in comparison with (-)-clau.
Song
Min
M
Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China.
Qian
Wen
W
Hang
Tai-Jun
TJ
Zhang
Zheng-Xing
ZX
D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004285:Dogs; D005260:Female; D007769:Lactams / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000493:pharmacokinetics*; D017705:Lignans / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000493:pharmacokinetics*; D008297:Male; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D027821:Rutaceae / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013237:Stereoisomerism
C519424:6-hydroxyl-clausenamide; D007769:Lactams; D017705:Lignans; C053048:clausenamide