OBJECTIVE: To develop a high-performance liquid chromatographic method for determination of ketamine and norketamine in blood and urine. METHODS: The compounds were extracted from blood or urine by liquid-liquid extraction using toluene after blood or urine was adjusted pH to 14. The extracts were analyzed by HPLC. RESULTS: Linear limits of ketamine and norketamine determination in blood ranged from 0.05 microg/mL to 10 microg/mL (R2 > 0.9993) and in urine ranged from 0.01 microg/mL to 200 microg/mL (R2 > 0.9995). Limits of detection (LODs) for ketamine and norketamine were 0.006 microg/mL and 0.003 microg/mL (S/N > or = 3), respectively. The mean extraction recovery was over 82.4% and its coefficients of variation were less than 10.0% for ketamine and norketamine. Concentration-time curves and urinary drug velocity curves of ketamine norketamine were obtained by determinations of them in blood and urine in rat using the developed method. CONCLUSION The method is sensitive, simple, rapid and suitable for determination of ketamine and norketamine in blood and urine for toxicological and clinical pharmaceutical analysis.
Animals ; Chromatography, High Pressure Liquid ; Female ; Ketamine/urine* ; Male ; Rats ; Rats, Wistar

OBJECTIVE: To investigate the toxicokinetics profiles of ketamine and its main metabolite norketamine in rabbits. METHODS: The rabbits were administered orally the hydrochloride of ketamine with a dose of 0.15 g/kg. The serum and urine samples were collected before administration and at different time points after drug administration. The concentrations of ketamine and norketamine were determined by GC-NPD and GC-MS. Compartment model and toxicokinetics parameters were simulated and calculated by WinNorLin program. Changes of important vital signs of rabbits were recorded during the experiment. RESULTS: The mean serum concentration-time profile of ketamine and norketamine were fitted to a two-compartment open model with first order kinetics. The kinetic equation of ketamine and norketamine were p(t) = 121.760 e(-0.0025t) +0.980 e(-0.002t) +4.579 e(-0.021 t) and p(t) = 640.919 e(-0.03 t) +1.023 e(-0.001 t) +9.784 e (-0.031 t), respectively. The peak time and the peak concentration of ketamine in serum were (40.950 +/- 12.098) min and (9.015 +/- 1.344) microg/mL, respectively. The elimination half-time of ketamine in rabbits was (430.370 +/- 28.436) min. The serum and urine showed a middle relation in concentrations of ketamine during 30-240 min after drug administration. After oral administration ketamine to rabbits, the toxic symptom on the rabbits occurred at 30 min and disappeared after 120 min. CONCLUSION The toxicokinetics parameters and kinetic equation of ketamine and norketamine in rabbits may provide the theoretical basis for forensic identification of reasonable specimen collection and inferring the time of oral administration ketamine from the ketamine concentration in serum.
Administration, Oral ; Anesthetics, Dissociative/toxicity* ; Animals ; Blood Pressure/drug effects* ; Gas Chromatography-Mass Spectrometry/methods* ; Heart Rate/drug effects* ; Ketamine/urine* ; Male ; Perceptual Disorders/etiology* ; Rabbits ; Random Allocation ; Time Factors