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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.
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Objective:To establish the criterion of bacterial endotoxins test for hemocoagulase atrox for injection and measure the endotoxin concentration in hemocoagulase atrox for injection by the kinetic turbidimetric technique. Methods:The limit of bacterial en-dotoxins in the product was designed according to ChP 2010. Four endotoxin concentrations were prepared to obtain the standard curve. The interfering test was done by measuring the concentration of endotoxin added into the sample solution. The endotoxin concentration in the sample solution was measured. Results:The absolute value of the correlation coefficient was 0. 988 6 (must be above or equal to 0. 980), suggesting the standard curve was valid. The recovery of the added endotoxin in the sample solution was within 50 to 200%when the concentration of the product sample was 0. 25 KU·ml-1 . The measured endotoxin concentration in the sample met the re-quirements for bacterial endotoxins. Conclusion:The bacterial endotoxins assay method for milrinone injections is established, and the kinetic turbidimetric technique is suitable for the bacterial endotoxin test of the product.
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The aim of this study was to determine the optimal experimental conditions to develop a methodology for microbiological assay of apramycin employing microplate and kinetic reading mode, and to validate the developed method, through evaluation of parameters of selectivity, linearity, linear range, limits of detection and quantification, accuracy and precision. The turbidimetric assay principle is simple: the test solution is added to a suspension of test microorganism in culture media, the mixture is incubated under appropriate conditions and the microbial growth is measured by photometric reading. Microplate with kinetic reading mode employed in antibiotic assay is of considerable interest since it allows reduction of material and analysis time and enables a large number of samples to be analyzed simultaneously, with automated reading and calculating. Established conditions considered the standard-curve of apramycin at concentrations from 5.0 to 35.0 μg mL-1, and tryptic soy broth inoculated with 5 percent Escherichia coli (ATCC 8739) suspension. Satisfactory results were obtained with 2 hours of incubation. The developed method showed appropriate selectivity, linearity in the range from 5.0 to 35.0 μg mL-1, limits of detection and quantification of 0.1 and 0.4 μg mL-1, respectively, as well as satisfactory accuracy (recuperation = 98.5 percent) and precision (RSD = 6.0 percent). Microplate assay combined the characteristics of microbiological (evaluation of antibiotic activity against sensitive test microorganism) and physico-chemical (operationally straightforward and faster results) assays.
O objetivo deste trabalho é determinar as condições experimentais ideais para o desenvolvimento de metodologia para a dosagem microbiológica de apramicina empregando microplacas e modo de leitura cinético e validar o método desenvolvido, através da avaliação dos parâmetros de especificidade e seletividade, linearidade, faixa ou intervalo linear, limite de detecção e quantificação, exatidão e precisão. O ensaio turbidimétrico é simples: a solução-teste é adicionada à suspensão de microrganismo-teste em meio de cultura, a mistura é incubada em condições apropriadas e o crescimento microbiano é medido por meio de leitura fotométrica. O emprego de método de microplacas com leitura cínética para a dosagem de antibióticos é de interesse considerável, uma vez que possibilita reduzir quantidade de material e tempo de análise necessários e permite o ensaio de grande número de amostras simultaneamente, com leitura e cálculo automatizados. As condições estabelecidas abrangem curva-padrão de apramicina com concentrações entre 5 e 35 μg/mL, e emprego de meio de cultura caldo de triptona-soja inoculado com Escherichia coli (ATCC 8739) na proporção de 5 por cento. Foram obtidos resultados satisfatórios após 2 horas de incubação. O método desenvolvido apresentou especificidade e seletividade adequadas, linearidade na faixa de 5 a 35 μg/mL, limite de detecção e quantificação de 0,1 e 0,4 μg/mL, respectivamente, exatidão (recuperação = 98,5 por cento) e precisão (DPR = 6,0 por cento) satisfatórias. O ensaio em microplaca agrega características dos ensaios microbiológicos (avaliação da atividade do antibiótico frente a microrganismo-teste sensível) e físico-químicos (facilidade operacional e maior rapidez na obtenção dos resultados).
Subject(s)
Biological Assay/methods , Microbiological Techniques/methods , Anti-Bacterial Agents/pharmacokinetics , Pharmaceutical Preparations/analysisABSTRACT
OBJECTIVE:To establish a method for the determination of the bacterial endotoxin content in isepamicin sulfate injection. METHODS: By using tinetic turbidimetric assay in which the sample was subjected to a serial dilution and the detection concentration of the sample was established by interference tests, meanwhile the standard endotoxin working curve was established for quantitative determination of the bacterial endotoxin in samples. RESULTS: The results showed that at a concentration of 6.25 mg?mL-1, isepamicin sulfate injection did no interference on tachypleus amebocyte lysate test. The bacterial endotoxin recovery ranged form 50% to 200%. CONCLUSIONS: It is feasible to use kinetic turbidimetry assay for the determination of bacterial endotoxin in isepamicin sulfate injection.
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OBJECTIVE:To discuss the relationship between the changes in pla sma endotoxin levels and use of antibiotics in patients with serious traumatic injury before and after operation.METHODS:The plasma bacterial endotoxin levels were dynamically detected by kinetic turbidimetric assay in20patients with severe traumatic injury used with different antibiotics before and after operation,at the same time the normal control group was established.RESULTS:Plasma endotoxin levels in patients with severe traumatic injury increased remarkably before and after operation,as compared with the normal control group(P0.05).CONCLUSION:Intestine-borne endotoxin induced in a stress condition can strengthen the pathological reaction of the body ,therefore dy?namic detection of plasma endotoxin can provide guidance for clinical therapy.
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OBJECTIVE:To explore the feasibility of detecting bacterial endoxins in low molecular weight heparins calcium injection LMWHC by tachypleus amebocyte lysate(TAL).METHODS:Bacterial endotoxins in samples were detected qualita?tively and quantitatively by kinetic turbidimetric assay and gel-clot method.RESULTS:Diluted to the concentration of25IU/ml,LMWHC had an obvious interference action to the TAL test,while not at the concentration of12.5IU/ml.The contents of bacterial endotoxins in all samples were less than0.01EU/IU.CONCLUSION:It is feasible to detect bacterial endotoxins in LMWHC by TAL test.