持续稳定性考察的时间应涵盖药品有效期，取样时间参照长期稳定性考察取样时间间隔。

长期稳定性考察至少与药品有效期考察时间等长，前 12个月，每 3 个月取样一次，之后与第 18 个月、24 个月、36 个月分别取样进行检测，将结果与0月比较以确定有效期。

持续稳定性考察的时间长短会影响以后延长有效期的策略，如果以后有这个打算，即使现在有效期是2年，也建议持续考察3年。

这一点， 中国也是支持的，在中国药监官网的问答中有类似的问题和解决，足够的数据至少要保持有统计分析的意义，五个点肯定是够的，不能少于3个点，比如中国药典关于加速稳定性的0.3.6设置，但3个点显得单薄了，除非你的产品足够稳定，风险可能才能接受。

可参考ICHQ1D 矩阵法设计，至少包含首次和结束点，同时前12个月至少3个测试点，对于24个月产品，需至少考察4个测试点。

In a design where time points are matrixed, all selected factor combinations should be tested at the initial and final time points, while only certain fractions of the designated combinations should be tested at each intermediate time point. If full long-term data for the proposed shelf life will not be available for review before approval, all selected combinations of batch, strength, container size, and fill, among other things, should also be tested at 12 months or at the last time point prior to submission. In addition, data from at least three time points, including initial, should be available for each selected combination through the first 12 months of the study. For matrixing at an accelerated or intermediate storage condition, care should be taken to ensure testing occurs at a minimum of three time points, including initial and final, for each selected combination of factors.