OBJECTIVE: To establish a high performance liquid chromatography (HPLC) method for the determination of 8-methoxypsoralen (8-MOP) in mouse plasma and apply it to a pharmacokinetic study of 8-MOP. METHODS: 8-MOP was separated on a Waters Symmetry18 column (250 mm × 4.6 mm, 5 μm) and determined by HPLC using isocratic elution, and 5-methoxypsoralen was used as internal standard. The mobile phase consisted of methanol-water (55:45, V/V) at a flow rate of 1.0 mL/min. The excitation and emission wavelength of fluorescence detector were set at 334 nm and 484 nm respectively, and the internal standard method was used for quantitative analysis. In the study, 60 healthy ICR male mice were randomly divided into twelve groups. The mice in control group were administered intragastrically with 1% Tween 80, and the mice in the other eleven groups were administered intragastrically with 8-MOP (40 mg/kg). Plasma concentrations of 8-MOP in the mice at different time points after treatment were determined by HPLC. Pharmacokinetic parameters were calculated by DAS 2.0 software. RESULTS: The calibration curve of 8-MOP was linear with a correlation coefficient of 0.999 3 over the concentration range of 0.05 to 10 mg/L, and the limit of detection was 0.015 mg/L. The average recoveries of 8? MOP at three different concentrations (0.10, 0.50, 2.5 mg/L) were from 92.5% to 100.6%. The intra-day precision of 8-MOP was from 3.3% to 8.2%, while the inter-day precision was from 3.4% to 6.7% at three spiked concentration levels. The extraction recoveries of 8-MOP were from 90.9% to 92.0%, and the plasma samples could be stored at -80°C for 15 days at least at three spiked concentration levels. 8-MOP could be detected in mouse plasma 5 min after intragastrical administration to the mice (1.4 mg/L). The concentration of 8-MOP in the mouse plasma reached a maximum 2 h after administration, and 8-MOP could still be detected 24 h after administration (1.1 mg/L). t_1/2 was (39.21±3.65) h, C_max was (2.31±0.02) mg/L, t_max was (2.00±0.00) h, and AUC0-t was (33.34±1.19) (h×mg)/L. CONCLUSION The proposed method is accurate and simple,suitable for pharmacokinetics of 8-MOP in mice.
Animals ; Calibration ; Chromatography, High Pressure Liquid ; Male ; Methoxsalen/pharmacokinetics* ; Mice ; Mice, Inbred ICR ; Photosensitizing Agents/pharmacokinetics* ; Plasma ; Random Allocation

OBJECTIVETo determine bergapten's concentration in plasma and observe its pharmacokinetics in rats using a combined LC-MS/MS analytical method.

METHODBlood samples were separated on a Hypersil ODS column (4.6 mm x 250 mm, 5 mm) at a temperature of 30 degrees C, and mobile phase consisted of water and methanol (22.5: 77.5) at a flow rate of 0.8 mL x min(-1).

RESULTThe methodological study showed a good linear relationship of 8.12-162.4 g x L(-1) (r = 0.9999). The inner and inter-days relative standard deviations were both less than 10% , indicating legitimate precise and accuracy to the requirement of biological sample analysis.

CONCLUSIONThe method is suitable for in vivo quantitative analysis for bergapten due to its accuracy, sensitivity and specificity. The pharmacokinetic process in rats forms a two-compartment model with first-order absorption.

Animals ; Chromatography, Liquid ; Male ; Methoxsalen ; analogs & derivatives ; blood ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley ; Reference Values ; Reproducibility of Results ; Sensitivity and Specificity ; Tandem Mass Spectrometry ; Time Factors

AIMTo investigate the penetration kinetics of xanthotoxin in human skin and stratum corneum.

METHODSThe penetration experiments were accomplished by the deposit of ethanolic xanthotoxin solution onto human skin and stratum corneum mounted on Franz cells. The diffused xanthotoxin in the receptor solution (1.4% human serum albumin) and the retained amount in the skin and in the stratum corneum after 24 h exposure were quantified by using high performance liquid chromatography.

RESULTSXanthotoxin flux was increased with the concentration deposited onto the human skin, and when the concentration is above 2.5 mg x mL(-1), there is no influence on the xanthotoxin flux. Similar results were obtained from the stratum corneum. And the peak time for the flux in the stratum corneum was preceded about 6 h earlier than that of the whole human skin. The retained xanthotoxin amount after 24 h exposure in the skin and in the stratum corneum increased according to the concentration deposited and has the tendency to saturate. The lag time of ethanolic xanthotoxin solution in the whole human skin is significantly higher than that in the stratum corneum (P < 0.05).

CONCLUSIONThe characteristics of penetration kinetics of xanthotoxin will provide the information for concentration choice of topical formulation and give a reference for ultra violet A (UVA) irradiation time confirmation.

Administration, Cutaneous ; Dose-Response Relationship, Drug ; Epidermis ; metabolism ; Female ; Humans ; In Vitro Techniques ; Methoxsalen ; administration & dosage ; pharmacokinetics ; Middle Aged ; Photosensitizing Agents ; administration & dosage ; pharmacokinetics ; Skin ; metabolism ; Skin Absorption ; Time Factors