系统适用性中重复性欧洲药典的方法

小吕飞刀

file:///C:\Users\mark\AppData\Roaming\Tencent\Users\181152134\QQ\WinTemp\RichOle\%~6LUT2TX66M]$Z`@NH}O14.png请问这重复性是怎么算的 ，为什么看不明白呢？

fangyuan5

看不明白。
我现在只知道EP有规定的按规定办，没有规定的按5针RSD不得过2.0%办。

hongwei2000

按照公式计算就可以得出表中的数据
当然如果个论中有就以个论为准

Doitasyoulike

这个重复性是考虑到90%置信上限的问题，你可以不用管，只需要按照提供的计算公式计算即可
其实在USP里也有类似的计算方法

Doitasyoulike

For the Assay in a drug substance monograph, where the value is 100% for the pure substance, and no maximum relative standard deviation is stated, the maximum permitted %RSD is calculated for a series of injections of the reference solution:
%RSD = KBn/t90%, n  1
where K is a constant (0.349), obtained from the expression K = (0.6/2) × (t 90%,5/6), in which 0.6/2 represents the required percentage relative standard deviation after six injections for B = 1.0; B is the upper limit given in the definition of the individual monograph minus 100%; n is the number of replicate injections of the reference solution (3 n  6); and t90%, n  1 is the Student’s t at the 90% probability level (double sided) with n  1 degrees of freedom.
Unless otherwise prescribed, the maximum permitted relative standard deviation does not exceed the appropriate value given in the table of repeatability requirements. This requirement does not apply to tests for related substances.
Relative Standard Deviation Requirements
        Number of Individual Injections
        3        4        5        6
B (%)        Maximum Permitted RSD
2.0        0.41        0.59        0.73        0.85
2.5        0.52        0.74        0.92        1.06
3.0        0.62        0.89        1.10        1.27

albertchen

以上的讨论只针对含量。杂质另当别论。

北辰/xs天

学习了学习了