ABSTRACT
Objective To evaluate the rat brain pharmacokinetics of tetramethylpyrazine phosphate (TMPP) after intranasal administration.Methods The pharmacokinetic behavior of TMPP in rat brain was investigated after intranasal or intravenous administration (10mg?kg-1) of TMPP.Brain samples were collected by intracerebral microdialysis.The concentration of TMPP in the sample was measured by high performance liquid chromatography (HPLC).Main pharmacokinetic parameters were calculated and analyzed by Das 2.0 pharmacokinetic software.Results The results showed that two administration methods were all fitted to one compartment model.The absorption of TMPP from the nasal cavity to brain was rapid.The concentration-time curve showed a prolonged duration of TMPP concentration in the brain after intranasal administration.AUC0-∞values were (698.26?122.59)?g?min?mL-1 in intranasal group and (446.25?107.44)?g?min?mL-1 in intravenous group,and the difference was significant between the two groups (P
ABSTRACT
Objective To study the characteristic of in-vivo nasal mucosa absorption of tetramethylpyrazine phosphate(TMPP) liposome in rats. Methods Nasal circulatory perfusion method in rats was used to study the effects of different circulatory rates and TMPP concentrations on nasal mucosa absorption of TMPP liposome. Nasal mucosa absorption rate constants of TMPP liposomes and TMPP solutions at the same concentration were also compared. Results The absorption rate constant of TMPP liposomes was increased with the increase of circulatory rates at the range of 1.2～2.4 mL/min and with the increase of TMPP concentrations at the range of 0.245～0.98 mg/mL. Both the absorption rate constant and absorbed amount of TMPP for TMPP liposomes were higher than those for TMPP solutions at the same concentration. Conclusion The nasal mucosa absorption of TMPP liposome was complete as compared with that of TMPP solution.
ABSTRACT
Objective To detect the in-vitro recovery of tetramethylpyrazine phosphate (TMPP) in microdialysis probe and to study its stability. Methods The recovery of TMPP was detected by concentration difference method (increment method and decrement method ). The effect of flow rates and concentrations on recovery was studied. Results The recovery detected by increment method was as the same as that detected by decrement method; TMPP recovery was independent of TMPP concentration in the external medium. TMPP recovery had good stability. Conclusion Microdialysis sampling can be used for the pharmacokinetic study of TMPP and decrement method (ie. retrodialysis) can be used for the determination of TMPP recovery.
