RESUMO
【Objective】 To develop and verify high performance liquid chromatography (HPLC) detection for tromethamine (Tris) residues in human coagulation factor Ⅷ. 【Methods】 Alanine was used as internal standard, and AQC for pre-column derivation. Inertsil® ODS-SP was adopted, and acetic acid-sodium acetate buffer and acetonitrile were used for gradient elution at the flow rate of 1 mL/min and column temperature of 37℃. The 25 μL sample was loaded and determined by UV-detector with detection wavelength at 248 nm. This method was then verified. 【Results】 Glycine, sodium citrate and calcium chloride showed no interference with the detection of tromethamine (Tris) residues. The recovery rate of spike samples was within 90.0%~100.8%. The RSD in repeatability test were 2.5%, 0.7% and 1.2%, respectively, and in intermediate precision test 0.8%. The tromethamine (Tris) at concentrates of (0.5~4.0)μg/mL showed good linear relationship to the peak area to internal standard, of which the regression equation was Y=0.012 9X-0.000 782, R=0.999 97.The quantitative detection limit was 0.04μg/mL. 【Conclusion】 The HPLC for determination of tromethamine (Tris) residues in human coagulation factor Ⅷ was successfully developed, which showed good linearity as well as high specificity, precision and accuracy.
RESUMO
【Objective】 To develop and verify a kinetic method for the determination of prekallikrein activator (PKA) content. 【Methods】 The optimal reaction conditions were determined by comparing the factors of pH and ionic strength of different sample dilution buffers, incubation time of each procedure, and incubation temperature. The accuracy, specificity, precision, linearity, stability and durability of the method were validated. 【Results】 The sample was diluted with 0.05 mol/L Tris-HCl buffer (pH8.5, containing 0.15 mol/L NaCl) and incubated by prekallikrein (PK) at 37℃ for 20 min. After that, the substrate S-2302 was added. Within 10 min before the measurement, the absorbance change rate reached △A405/min. The validation results indicated that the linear range of the method was (0.5~4.0)IU/mL, while the recovery of calibration standard was 96.9%~103.7% with the R2 value more than 0.99. The specificity test showed that human serum albumin, excipients of intravenous human immunoglobulin (pH4), low pH and protein content had no significant effect on the detection of PKA, The recovery rates of standard sample solution in the specificity experiment were 98.0% (0.9% sodium chloride solution), 95.3% (0.46% sodium caprylate solution), 96.7% (10% maltose solution, pH4.0), 94.0%(20%BSA), and 94.0%(5%BSA, pH4.0), respectively. The accuracy and precision of the method can meet requirements in the range between 0.5 and 4.0 IU/mL. The inter-batch recovery rate of quality control samples were between 96.4%~109.5% with the coefficients of variation(CV) between 0.2%~6.9%, while the intra-batch recovery rate were between 101.5%~102.9% with the CV between 2.6%~5.9%. The linearity, accuracy and precision of the assay can meet the requirements when PK and S-2302 were placed at room temperature for less than 6 hours, with the recovery rate of quality control samples between 94.9%~109.9%. The end-point method and kinetic method were used to determine the PKA in 20 batches of human serum albumin, and the consistency showed that there was no significant difference between the two methods(P>0.05). 【Conclusion】 A kinetic method for determination of PKA content with good linearity, specificity, accuracy, precision, stability and durability has been established. Compared with the method in ChP, the new method is more convenient, accurate and rapid to determine the content of PKA in human albumin and human immunoglobulin (pH4) for intravenous injection.