RESUMEN
Objective: To study the pharmacokinetic behavior of tetramethylpyrazine hydrochloride (TMPH) in plasma of rabbits after intranasal administration and the relationship between absorption and dosage, furthermore, to illustrate the effects of borneol and musk used in combination with TMPH on the plasma concentration profile of TMPH in rabbits. Methods: The concentration of TMPH was determined by RP-HPLC method. Coumarin was used as an internal standard. Sample preparation was carried out by extraction and precipitation with methanol. The pharmacokinetic parameters were computed by software program DAS.3.1.4. Results: Blood pharmacokinetics of TMPH fitted best to a non-compartment model. After intranasal administration with single dose at 10, 20, and 40 mg/kg of TMPH, the average values of Cmax were 8.075, 16.537, and 33.115 μg/mL, and the average values of AUC>0-t were 228.93, 399.273, and 728.917 mg/(L·min), respectively. Cmax of TMPH in plasma was increased by 31.136% and 38.786% compared with those without borneol and musk, and intranasal bioavailability were increased by 21.587% and 40.633% after intranasal administration of TMPH in combination with borneol, or with borneol and musk. Conclusion: Borneol and musk could enhance the intranasal absorption of TMPH and increase the concentration of TMPH in blood of rabbits, especially in the early period. This work also shows the rational compatibility between borneol and musk.
RESUMEN
OBJECTIVE: To develop an HPCE method of tetramethylpyrazine hydrochloride in rat plasma using pyramide as the internal standard. METHODS: The separation was performed on a fused-silica uncoated capillary with an inner diameter (ID) of 75 μm, an effective length of 50 cm and a total length of 60 cm. The optimum HPCE conditions were as follows: 100 mmol·L-1 SDS-30 mmol·L-1 sodium tetraborate solution (40:60) was used as the background electrolyt, the samples were injected at the anodic end at 0.5 psi for 6 s, separation voltage was 20 kV at positive power, capillary temperature was 20°C, and detection wavelength was 295 nm. RESULTS: The linear range was 1.12-286.72 mg·L-1(r=0.9996), and the inter-day and intra-day precisions expressed as RSDs were less than 4.21% and 4.74%, respectively. The average recoveries were 91.22%-97.48%, and the limit of detection was 0.16 mg·L-1. CONCLUSION: This method is rapid and accurate to quantify tetramethylpyrazine hydrochloride in rat plasma.
RESUMEN
Pharmacokinetics of Tetramethylpyrazine Hydrochloride (TMPH) in rat was studied by using Ultraviolet Spectrophotometry. After a bolus iv injection of TMPH 30 mg/kg to rat, the pharmacokinetic characteristics are found to fit a two-compartment open model. The Pharmacokinetic parameters are: t 1/2? = 0 .1441h, t 1/2? = l .6953h, K21=2.1850h-1, K10=0.8605h-1, K12= 2 .0723h-1, AUC = 83 .3660mg?L -1h, CL = 0.3599L?kg-1h-1, Yc =0 .4182L?kg-1 , Vss =0 .7975L.kg-1