ABSTRACT
Aim To investigate the pharmacokinetic properties and in vitro enzyme activities of D-a-to- copherol polyethylene glycol 1000 succinate-modified arginine deiminase cyclodextrin lipid nanoparticles (ACLN). Methods The diacetylmonooxime-thiosem- icarbazide colorimetric method was used to determine the ADI enzyme activity, and the double reciprocal plot method was used to determine the enzyme Michae- lis constants. After the rats were given intravenously free ADI and ACLN, rat plasma samples were taken at different time points to determine the activity of ADI, and the time-enzyme activity curve would be drawn and the pharmacokinetic data analyzed by DAS 2. 1. 1. Re¬sults The optimum temperature for ADI and ACLN was 37 °C and the optimum pH was 6. 5. The Km val¬ ues of free ADI and ACLN were 0. 87 and 0. 74 mmol • L"1, respectively. The Vmai values of free ADI and ACLN were 53.28, 62.50 fjimol • L"' • min"1, re-spectively. The V
ABSTRACT
Aim To establish a HPLC method for de-termining cimifugin in rat plasma and investigate the pharmacokinetic characteristics of cimifugin in rats. Methods The plasma concentration of cimifugin was detected by HPLC in acetonitrile protein precipitation method after intragastric administration of cimifugin. The pharmacokinetic parameters were calculated by the procedure of DAS 2 . 1 . Results The regression equa-tion of cimifugin in rats plasma was Y =0. 187 X -0. 0236 (R2 =0. 998 2),which shows a good linear re-lation at 1 - 70 mg · L-1 . The concentration-time curves conformed to two-compartment model. The main pharmacokinetic parameters of Tmax, Cmax, T1/2α, T1/2z, Vd ,AUC(0-t) and AUC(0-∞) were 80 min, 10. 359 mg ·L-1 , 93. 131 min, 2. 179 L · kg-1 , 1946. 085 mg ·L-1 · min, 2138. 57 mg · L-1 · min, respectively. Conclusions We established a HPLC method to de-termine the concentration of cimifugin in plasma. The method is so highly specified and sensitive that it can be used in quantitative analysis in vivo on cimifugin. Cimifugin can be rapidly absorbed, reach the highest concentration and produce effect.