Hplc Method For The Determination Of The Concentration Of The Three Drugs In Human Blood And Human Pharmacokinetics And Bioequivalence Studies

Objective:To establish a HPLC method for determination of concentration of dextromethorphan hydrobromide in human serum. The pharmacokinetic profiles and the bioavailability of dextromethorphan were studied in 20 normal male volunteers.Methods:The assay was conducted on HiQsil C18 column (4.6mm×150mm,5μm) with acetonitrile-water-acetic acid (35:63:2,V/V/V) as mobile phase. The fluorescence detector measured with the excitation wavelength of 280nm and the emission wavelength of 320nm, and carvedilol was taken as internal standard.Results:The linear range of calibration curve of dextromethorphan hydrobromide was 0.27-21.90ng/ml with a regressive equation of Y-0.1334X-0.0329 (r=0.9995 n=7).The recovery was high.20 healthy male volunteers were randomly administered with an oral single dose of dextromethorphan hydrobromide plenol Asami Min drops and Tyenol liquid plenol Asami Min 20mg. The plasma concent ration of dextromethorphan and its main Metabolite, dextrorphan, were determined by HPLC fluorescene method. The pharmacokinetic parameters for dextromethorphan drops were as follow s respectively: t1/2:(20.61±13.44)h, tmax:(1.75±0.47)h, Cmax:(7.59±7.27) ng/ml; Tyenol liquid t1/2:(19.26±9.69)h, tmax:(1.7±0.57)h, Cmax:(7.06±5.75) ng/ml。Conclusion:This method is accurate, rapid and simple, and can be used for determining the concent ration of dextromethorphan hydrobromide in human serum. The relative bioavailability was (100.11±29.49)%. The results of analysis of variance, two one-sided tests showed that two formulations were bioequivalent. Objectiv:To establish a method for determination of mycophenolic acid in human plasma.Methods:Mycophenolic acid was determined by HPLC using a HYPERSIL C18(150 mm×5 mm,5μm) column and a guard column ODS(5 mm×3.9 mm,10μm), the mixture of methanoland and NaH2PO4(pH= 3.25) and acetonitrile (40:40:20, V/V/V) as mobile phase with a flow rate of 0.8 mL/min. The temperature of column was 25℃and the wavelength of detection was 254 nm.Results:The standard curve was linear in the range of 0.12-46.13 mg/L (r =0.9997),the method recovery was more than 96%, and the intra-day and inter-day RSD were all less than 7%.Conclusion:This method is reproducible, convenient and sensitive for determination of plasma concentration and can be used to study clinical pharmacokinetic mycophenolic acid. Objective To establish a method of determining serum vancomycin in human by RP-HPLC.Methods Separation was carried out on a HYPERSIL C18-ODS column, the mobile phase consisted of methanol, acetonitrile and buffer(pH 3.2) (15:85),flow rate was 1.0 mL/min, UV detector wavelength was 236 nm. Norvancomycin was used as internal standard.Results A good linearity was demonstrated between 1.25～100 mg/L by linear equation Y=0.0277X-0.0596 (n= 8, r= 0.9993). The intra-day and inter-day deviation was showed by RSD<10%.Consulsion The method is validated for determination of serum vancomyc in clinical p ractice.