ABSTRACT
OBJECTIVE:To determine the concentration of cefdinir in rat plasma,and investigate its pharmacokinetics. METH-ODS:High performance capillary electrophoresis (HPCE) was adopted by using fused-silica capillary (75 μm,total length of 30 cm,effective length of 21.5 cm),buffer solution of 20 mmol/L citric acid,injection voltage of 10 kV for 10 s,separation voltage of -20 kV,and detection wavelength of 214 nm. 6 rats were intragastrically received cefdinir solution(20 mg/kg). 0.2 mL blood sample was taken from the tail vein before and 0.25,0.5,1,1.5,2,3,4,6,12,24 h after administration. BAPP 2.0 software was used to calculate the pharmacokinetics parameters. RESULTS:The linear range of cedinir ranged 0.2-50 μg/mL(r=0.9997), lower limit of quantification was 0.2 μg/mL. The intra-day(n=6)and inter-day RSDs of(n=3)precision test were no more than 12.2%;RSD of stability test was no more than 9.10%(n=6);method recovery rate was 95.4%-114.3%(RSD=9.0%,n=6);matrix effect was 63.5%-70.2%(RSD=10.39%,n=6). The t1/2 of cefdinir in rats in vivo was(0.54±0.01)h,MRT was(1.90± 0.14)h,cmax was(32.92±0.81)μg/mL,tmax was(1.50±0.02)h,AUC0-24 h was(46.65±0.44)μg·h/mL and AUC0-∞was(46.83± 0.44)μg·h/mL. CONCLUSIONS:The method is rapid,accurate and simple,and can be used for the determination of cefdinir con-centration in rat plasma and its pharmacokinetics research.
ABSTRACT
Objective To compare the effects of dual-wavelength spectrophotometry and HPLC on the content of trimethoprim(TMP)in Compound Dihydroartemisinin Tablets.Methods HPLC was performed in a column of C 18 with acetonitrile and 0.75% diethylamine(15∶85,adjusting pH to 2.5 by phosphoric acid)as the mobile phase and the detecting wavelength was at 271nm.The detecting wavelength was also at 271nm with reference wavelength at 366nm in dual-wavelength spectrophotomerty.Results Within 20.0～100.0 ?g/mL,TMP has a good linearity(r=0.999 94)by HPLC,and the average recovery was 100.9% with RSD being0.24%(n=5).By dual-wavelength spectrophotometry,a good linearity(r=0.999 95)of TMP was within 5.0～25.0 ?g/mL,and the average recovery was 100.0% with RSD being 0.45%(n=5).Conclusion Both dual-wavelength spectrophotometry and HPLC can be used to determine the content of TMP in Compound Dihydroartemisinin Tablets,but the former can detect the content of TMP directly without the disturbance of piperaquine phosphate and is simple,rapid and accurate.