How to calculate the retest period from the sample acceleration test data

If there is almost no change in the 6-month accelerated trial, the intermediate condition test can be omitted or the intermediate condition test that has been carried out can be cancelled, and the long-term trial can be continued. In this case, if you want to report to the authorities, the principle of validity is as follows:

the proposed retest period or shelf life can be up to twice, but should not be more than 12 months beyond, the period covered by long-term data.

If the validity period of the declaration (e.g., one and a half years) is approved, the long-term trial must be valid for this period (e.g., one and a half years) to confirm that the earlier approval was in effect at that time.

Generally speaking, new drugs will be tested for as long as possible to confirm their true expiration date, of course, if you think one year of expiration is enough, you don't have to do two years.

Does the landlord understand, I also saw that article, but I don't understand why it is related to the number of samples?

No way? What kind of aging test? Learned.

It must be within the validity period, otherwise the validity of the test data will not be reliable, and the stability test data will be unreliable, which will affect the consistency evaluation, so the preparation must be within the validity period.

A: This is a deceptively simple question, but the answer is complex. Theoretically, we can't get a simple number and multiply it by the test time of the weathering chamber to get the outdoor exposure time.

It's not that we haven't developed better test chambers, it's that no matter how advanced and expensive your weather-resistant test chambers are, you still can't find that number. In fact, the biggest problem is that the environment of outdoor exposure is complex and changeable. The test time in the test chamber and the outdoor exposure time are related to the following factors:

1. Altitude (higher altitude means stronger ultraviolet rays).

2. The geographical latitude of the outdoor exposure site (the closer to the equator, the stronger the ultraviolet rays).

3. The local geographical environment, such as wind speed will affect the degree of air-drying of the test sample or the place close to the water source will promote the formation of dew.

4. Due to the different climate of each year, the influence of the weather in the same area on the samples in the following year may be twice the influence of the season in the previous year, for example, the destructive effect of winter exposure is only 1 7 The orientation of the sample in summer.

5 degrees south and due north are very different).

5. Whether the sample is insulated or not (outdoor samples are usually aged 50% faster when placed on an insulating carrier than when not placed on an insulating carrier).

6. The test cycle of the test chamber (irradiation time and humidity time).

7. The operating temperature of the test chamber (the higher the temperature, the faster the aging).

8. Testing of special materials.

9. Spectral distribution (SPD) of laboratory light sources

Therefore, it makes no sense to logically talk about the conversion factor between the artificial accelerated aging time and the outdoor exposure length. The reason for this is that one is a fairly constant environment, while the other is ever-changing. Finding the conversion factor between the two is beyond the scope of variation.

In other words, weather data is relative.

However, you can still get excellent weathering data from the Artificial Accelerated Aging Test. But you have to recognize that the data is relative, not absolute. The reliable data you get from laboratory tests is the relative grade of aging of the tested material compared to other materials.

According to the standard of aging test, the main influencing factors are: light intensity, temperature, and humidity. If it is according to the GB GB

For experiments, 1200 hours is basically a year. In fact, there is no clear conversion method, and correlation requires a lot of data to support! Moreover, there are many factors that affect aging, and the results of outdoor exposure are definitely different between a year in Beijing and a year in Guangzhou.

So, with us.

Wuhan is still testing equipment****.

From many years of experience and frequent communication with customers, customers still want to know about the relationship between each other, or the conversion relationship, and of course, this hopes that the relevant experts and research institutions can solve this problem.