ABSTRACT
Aim To establish a batch of endotoxin standard for baeterial endotoxin detection of insoluble samples.Methods Candidate A and candidate B were prepared by freeze -drying bacterial endotoxin without excipient.The two batches of candidates were calibrated by three methods, including 13 laboratories for gel method, 9 laboratories for kinetic-turbidimetric assay and 5 laboratories for kinetic chromogenic assay.Results After statistical analysis, the geometric mean values of gel method, kinetic-turbidimetric assay and kinetic chromogenic assay calibration of candidate A were 680.1 EU, 827.0 EU and 800.8 EU, with RSD of 22.4%, 16.2% and 16.7%, respectively.The P value of variance analysis of calibration results of the three methods was 0.067, showing no significant difference.The weighted mean of potency was 774.0 EU (95% confidence interval 721.0 - 831.0, FL% 7.10).The geometric mean values of the calibration of candidate B by gel method, kinetic-turbidimetric assay and kinetic chromogenic assay method were 1 640.6 EU, 1 828.6 EU and 3 224.8 EU, with RSD of 33.9% , 47.0% and 54.4% , respectively.The P val¬ue of variance analysis of the calibration results of the three methods was 0.030, showing significant differ¬ence.Chi-square test was used to correct the weight of each method , and weighted average of the results of the three methods was used to obtain a corrected weighted average efficiency value of 1 822.7 EU (95% confi¬dence interval 1 548.7 -2 145.2, FL% 16.4).Can¬didate B was eliminated based on the results.Conclu¬sion Candidate A has become the first batch of na¬tional standard bacterial endotoxin (for insoluble sam¬ples only) approved by National Standard Substance Committee of China, and the potency is 700 EU.
ABSTRACT
Aim To evaluate the equivalence between micro kinetic chromogenic assay anrl kinetic chromogenic assay in order to provide data support for the use of alternative methods.Methods Detection conditions; micro kinetic chromogenic assay and kinetic chromogenic assay limulus reagent were used, sample amount of each well and limulus reagent was 25 jxL ( kinetic chromogenic assay was 100 jxL) , detection wavelength was 405 nm, ONSET OD value was 0.03, and half- well elisa plate was used for detection ( kinetic chromogenic assay was ordinary ELISA plate).The equivalence of the two methods was evaluated by various statistical methods, such as equivalence test, in collaboration with four laboratories in China.Results The results of one-way an OVA, paired T test and equivalence test were consistent, indicating that there were some differences between the existing kinetic chromogenic assay of different manufacturers, while there was no significant difference between the trace or conventional amount of reagent used by each manufacturer.Conclusions Micro kinetic chromogenic assay is e- quivalent to existing reagents in terms of accuracy and recoverv.J.
ABSTRACT
Abstract; Aim To solve the problems in the appliea- tion of egg yolk leeithin endotoxin test method, and and to establish the baeterial endotoxin examination method for egg yolk lecithin (for injeetion). Methods The ethanol solution of Tween 80 ( the volume ratio of tween 80 to anhydrous ethanol was 2. 5 • 2. 7, mixed for 4 min) was used to prepare lecithin solution of egg yolk at 0. 1 kg • L 1 , and 10 test water was added to 1 mL lecithin solution of egg yolk (500 EU • mL 1 standard solution of endotoxin IOjxL was added for pos¬itive control). After diluted 20 times with endotoxin test water, the standard curve range was 10 ~0. 01 EU • mL 1 by kinetic-turbidimetrie assay. Methodology of endotoxin test was studied using limulus lysate from two manufacturers and eight hatches of samples. Results The recoveries of eight hatches of samples all met the requirement of interference test between 50% and 200% stipulated in the pharmacopoeia, which solved the problems of the current endotoxin test method in practical application. Conclusions The bacterial en¬dotoxin test method of egg yolk lecithin with good dura-bility is established to provide the basis for the revision of pharmacopoeia.