A high‐performance liquid chromatographic method for determination of mitragynine in serum and its application to a pharmacokinetic study in rats

Abstract

A simple HPLC technique for determining mitragynine levels in serum was developed. The separation system consisted of a C18 column heated to 35 degrees C, a methanol-water (80:20, v/v) mobile phase, a flow rate of 0.8 mL/min and detection in the ultraviolet at 225 nm. Mitragynine, with a retention time of 10.09 min, was well resolved from any interferences in human serum and the internal standard peak. The calibration curve was linear from 0.1 to 10 microg/mL (r = 0.9995). Extraction of mitragy-nine from alkalinized serum using diethyl ether gave a high recovery (>or=85%). The intra- and inter-day precisions of the method were 4.29-5.88%RSD and 7.06-8.45%RSD, respectively. The accuracy ranged from -9.54 to +0.67%DEV. The limit of detection was 0.03 microg/mL and the lower limit of quantification was 0.1 microg/mL. Mitragynine in the stock solution was stable during 30 days of storage at 4 degrees C. This method was successfully applied to determine the pharmacokinetic characteristics of mitragynine levels in the serum of rats after it was administered orally.

Intrahepatic Cholestasis Following Abuse of Powdered Kratom (Mitragyna speciosa)

“…Thus, the shortest latency could be 2-3 days between the last kratom use and the first sampling of urine (on day 3 after admission to the hospital), though was more likely to be 10-14 days. So far, the elimination half-life (serum and plasma) was only studied for mitragynine in rats and was found to be approximately 4-9 h after a single dose [25,26]. Considering the described half-life, the finding of mitragynine in the serum and in the urine of the patient after the assumed interval suggests a severely prolonged elimination half-time of the alkaloids.…”

Enantioselective HPLC‐UV method for determination of eslicarbazepine acetate (BIA 2‐093) and its metabolites in human plasma

“…Besides the specific chromatographic conditions, the SPE procedure used here in sample pretreatment offers many other benefits over the traditional liquid-liquid extraction methods, such as faster sample preparation, lower cost, greater recoveries, less sample handling, improved safety and easy automation (Soriano et al, 2001;Camel, 2003). Even though ESL and its metabolites could be analyzed using MS detection systems (Hainzl et al, 2001;Almeida et al, 2005), most hospitals and laboratories are not equipped with such high-cost instruments (Velpandian et al, 2004;Janchawee et al, 2007). Therefore, the availability of the current method will be important and it may be easily adopted to perform clinical studies.…”

Seizure and Coma Following Kratom (Mitragynina speciosa Korth) Exposure

“…As this is the first biologic human specimen obtained in a clinically ill patient following kratom use, it is presently impossible to correlate a urinary concentration with clinical effects. Preliminary pharmacokinetic (PK) analysis of mitragynine in rats suggest a time to maximum concentration of 1.2-1.8 h, an elimination half-life of 3.85-9.43 h, and a volume of distribution 37.9-89.5 L/kg [7,8].…”