The selection of standard sample stability research program is based on the internal mechanism of stability research and analysis. So far, two basic stability testing programs have been proposed in the field of standard sample technology. The following is a small edition of Bolinda to give you a detailed introduction.

The first is the traditional stability study scheme. This scheme is: under ideal conditions, the samples prepared at the same time according to the pre-specified time order, bottle by bottle testing, and through the statistical analysis of the test data to determine the validity of the standard sample. Obviously, there are two problems with this approach:

First, because the detection is carried out at different times, the detection conditions at this time can basically be said to be repeatability conditions. That is, although the use of the same detection method, the same operator, the same instrument; However, due to the change of time, the accuracy level of the instrument, the operator's operating techniques, and the detection environmental conditions are also changing, so the measurement uncertainty of the detection method is also changing.

Therefore, even if the sample is stable, at each specific detection time point, the measurement uncertainty obtained by detecting the sample may be larger than that obtained when the measurement uncertainty is fixed. At this time, it is difficult to determine whether the increase in measurement uncertainty is caused by the change of sample material or the change of detection method conditions.

Second, the prerequisite of this scheme is that the sample change must be uniform, if the sample change is not uniform in the bottle or between the bottle and the bottle, the test data obtained by the test sample may not be representative at each specific test time point. When the sample obtained at a certain detection point is exactly the same as the sample, we may misjudge the whole batch of samples with unqualified stability as qualified.

In order to solve the defects of these traditional stability research schemes, a new stability research scheme, synchronous stability research scheme, has been proposed internationally.

The synchronous stability research scheme can solve the above two defects theoretically. The difference between the synchronous stability study scheme and the traditional stability study scheme is that in the synchronous stability study scheme, several bottles of samples are tested simultaneously at each specific testing time point. In this way, the testing of these bottles of samples is a repeatable condition for each testing time point.

Because at any given point in time, the interference introduced by the time change is the same for each bottle sample and measurement method. Because several bottles of samples are tested simultaneously at each specific testing time point, the problem of unrepresentative sampling is avoided.

The above content is the introduction to the selection of standard sample stability test scheme, from which it can be seen that the synchronous stability research scheme, theoretically speaking, can indeed overcome the two defects in the traditional stability research scheme, and reflect the actual situation more scientifically and reasonably. However, the research scheme of synchronous stability is short in time and lacks practical experience. At the same time, in the process of implementation, due to the need for more samples, the cost is relatively large.