ICH Q1E Evaluation of Stability Data

2.3 Extrapolation外推法

Extrapolation is the practice of using a known data set to infer information about future data. Extrapolation to extend the retest period or shelf life beyond the period covered by long-term data can be proposed in the application, particularly if no significant change is observed at the accelerated condition. Whether extrapolation of stability data is appropriate depends on the extent of knowledge about the change pattern, the goodness of fit of any mathematical model, and the existence of relevant supporting data. Any extrapolation should be performed such that the extended retest period or shelf life will be valid for a future batch released with test results close to the release acceptance criteria. 

外推法是一种根据已知数据来推断未来的数据的方法。在申报中，可用外推法建立超过长期试验数据覆盖时间范围的复验期或有效期，尤其适用于在加速试验条件下没有发生明显变化的情况。对稳定性数据进行外推的合理性取决于对变化模式的了解程度、数学模型的拟合度和相关支持性数据。任何外推法应保证外推得到的复验期或有效期对未来放行时检验结果接近放行标准的批次是有效的。

An extrapolation of stability data assumes that the same change pattern will continue to apply beyond the period covered by long-term data. The correctness of the assumed change pattern is critical when extrapolation is considered. When estimating a regression line or curve to fit the long-term data, the data themselves provide a check on the correctness of the assumed change pattern, and statistical methods can be applied to test the goodness of fit of the data to the assumed line or curve. No such internal check is possible beyond the period covered by long-term data. Thus, a retest period or shelf life granted on the basis of extrapolation should always be verified by additional long-term stability data as soon as these data become available. Care should be taken to include in the protocol for commitment batches a time point that corresponds to the end of the extrapolated retest period or shelf life.

稳定性数据的外推是假定：在所获得的长期试验数据覆盖范围外， 其变化模式相同。在考虑采用外推法时，所假定的变化模式的正确性是关键。当判断长期数据是否符合直线回归或曲线回归时，数据本身也可验证所假设的变化模式的正确性，并可用统计方法对数据与假设的直线或曲线的拟合程度进行检验。在长期数据覆盖的时间范围外，不可能进行这种相互验证。因此，由外推法得到的复验期或有效期，应及时采用后续得到的长期稳定性数据不断进行验证。尤其要对承诺的批次，在外推的复验期或有效期的最后时间点上用测得的数据进行验证。

可以啊，但是ICH Q1E里也说明了一些不能外推的条件，可以对照着译文读一下，指南里说的还是很清楚的。