Ludwig J D, Avis K E
University of Tennessee, College of Pharmacy, Department of Pharmaceutics, Memphis.
J Parenter Sci Technol. 1990 Jan-Feb;44(1):4-12.
The thermal inactivation of three endotoxin preparations on the inner surface of glass capillary tubes was studied. The samples were exposed to precisely controlled dry heat conditions at study temperatures ranging from 170 degrees to 350 degrees C, and were assayed using the gel-clot method of the Limulus Amebocyte Lysate test. Plots of the log of the amount of pyrogenic material remaining versus heating time revealed apparently biphasic destruction curves. The initial slopes were linear to a minimum 3-log unit reduction, and were followed by slower destruction rates for the terminal slopes. D values were calculated from the initial slopes of the destruction data, and Z values were estimated from the D values. The D and Z values were found to vary with the initial charged amounts of endotoxin. A second-order equation was found to be an inappropriate model for the inactivation process at temperatures between 170 degrees and 250 degrees C, but was found to be suitable for temperatures between 250 degrees and 325 degrees C. The data were successfully fit to a biexponential equation for all the temperatures studied. The overall inactivation rate of the endotoxin material formulated with fillers was apparently faster than that for the pure endotoxin preparations.
研究了玻璃毛细管内表面上三种内毒素制剂的热灭活情况。将样品置于170℃至350℃的研究温度下，精确控制干热条件，并采用鲎试剂凝胶法进行检测。剩余热原性物质的量的对数与加热时间的关系图显示出明显的双相破坏曲线。初始斜率在至少3个对数单位的降低范围内呈线性，随后的终末斜率破坏速率较慢。根据破坏数据的初始斜率计算D值，并根据D值估算Z值。发现D值和Z值随内毒素的初始电荷量而变化。对于170℃至250℃之间的温度，二阶方程被证明不适用于灭活过程的模型，但对于250℃至325℃之间的温度则适用。对于所有研究温度，数据均成功拟合双指数方程。添加了填充剂的内毒素物质的总体灭活速率明显快于纯内毒素制剂。
