ABSTRACT
A high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed and validated for the determination of mizoribine in human serum using thiamphenicol as internal standard (IS). The serum samples of mizoribine were precipitated with acetonitrile and separated by HPLC on a reversed phase C18 column with a mobile phase of 0.1% ammonium acetate water solution-methanol (47:53, v/v). Mizoribine and IS were detected in the multiple reaction monitoring mode with precursor/product ion transitions of m/z 258.2/126.0 and 354.1/185.2, respectively. The calibration curves were linear over the range of 0.02-2 microg mL(-1) for mizoribine. The limit of quantification (LOQ) was 0.02 microg mL(-1) with acceptable precision and accuracy. The validated method was successfully applied for the evaluation of a bioequivalence study on Chinese healthy volunteers. The main pharmacokinetics parameters after oral administration of 100 mg mizoribine test or reference formulation were as follows: Cmax (1.00 +/- 0.21), (1.00 +/- 0.22) microg mL(-1); AUC(0-infinity) (6.72 +/- 1.39), (6.48 +/- 1.44) microg h mL(-1); t1/2 (2.77 +/- 0.26), (2.66 +/- 0.29) h; tmax (2.95 +/- 0.78), (2.84 +/- 0.50) h.
Subject(s)
Adult , Humans , Male , Young Adult , Area Under Curve , Asian People , Chromatography, High Pressure Liquid , Methods , Confidence Intervals , Enzyme Inhibitors , Blood , Pharmacokinetics , Immunosuppressive Agents , Blood , Pharmacokinetics , Ribonucleosides , Blood , Pharmacokinetics , Spectrometry, Mass, Electrospray Ionization , Methods , Therapeutic EquivalencyABSTRACT
<p><b>AIM</b>To establish an HPLC-fluorescence method for determination of loratadine in human plasma and evaluate its relative bioavailability.</p><p><b>METHODS</b>An Alltech-C18 column and a mobile phase of acetonitrile-water-glacial acetic acid-triethylamine (90:100:6:0.15) were used. The fluorescence detector was set at Ex 274 nm, Em 450 nm. The flow rate was 1 mL.min-1.</p><p><b>RESULTS</b>The calibration curve was linear over a concentration range of 0.2-30 micrograms.L-1. The limit of quantification was 0.2 microgram.L-1. The average method recoveries varied from 96% to 98%. The results showed AUC, Tmax, Cmax and T1/2 beta between the testing tablets, testing capsules and reference tablets had no significant difference (P > 0.05). Relative bioavailabilities were 107% +/- 17% and 100% +/- 14% respectively.</p><p><b>CONCLUSION</b>The three formulations were bioequivalent.</p>
Subject(s)
Humans , Male , Area Under Curve , Biological Availability , Chromatography, High Pressure Liquid , Methods , Fluorescence , Histamine H1 Antagonists, Non-Sedating , Blood , Pharmacokinetics , Loratadine , Blood , PharmacokineticsABSTRACT
Aim To study relative bioavailablity of cefaclor effervescent tablets in healthy volunteers. Methods According to the crossover design, A volunteers were each orally given a single does of the 0.75 g cefaclor effervescent tablets and cefaclor capsules with an interval of 5 days between the two formulations.The plasma concentrations of the drug were determined by RP-HPLC.Pharmacokinetic parameters were obtained by ATPK programe,and calculated on the basis of open single compartment model.Results After a single oral dose, the peak levels in plasma averaged Cmax(31.27?5.81)?g?ml-1 and(30.56?5.25) ?g?ml-1 at (0.58?0.12)h and(0.73?0.17)h and AUC0～4(35.48?4.65) ?g?h?ml-1 and (35.89?2.90) ?g?h?ml-1 for tablet and capsule,respectively. Conclusion The result shows that two formulations are bioequivalence.
ABSTRACT
0. 05). Conclu-sion The THT and THC have bioequivalence.