What is a Drug Stability Test?

The drug stability refers to the ability of raw materials and preparations to maintain their physical, chemical, biological and microbiological properties. The purpose of stability research is to investigate the law of change of the nature of the drug substance or preparation over time under the influence of temperature, humidity and other conditions, to provide a scientific basis for the production, packaging, storage, transportation conditions and determination of expiration date of the drug to ensure the safety and effectiveness of clinical drug use.

Test methods for stability research: long-term test, accelerated test, and influencing factor test.

The long-term test is conducted under the storage conditions prescribed by the marketed drugs. The purpose is to investigate the stability of the drugs during transportation, storage, and use. It can directly reflect the stability characteristics of the drugs and is the ultimate basis for determining the validity period and storage conditions.

The accelerated test is carried out under abnormal conditions. The purpose is to investigate the stability of the drug by accelerating the chemical or physical change rate of the drug in the commercial packaging. It aims to simulation study the stability of the drug under short-term abnormal conditions that may be encountered during transportation and storage, and preliminarily predict the long-term stability of the sample under the specified storage conditions.

Ⅰ. How to test drugs in the stability test chamber

The test of influencing factors is conducted under severe conditions. The purpose is to understand the factors affecting stability, possible degradation pathways and degradation products, and to provide basis for preparation process screening, packaging materials and container selection, and storage conditions determination. At the same time, it provides a basis for the temperature and humidity conditions that should be used in the accelerated test and the long-term test, as well as the basis for the selection of analysis methods.

Both temperature and humidity tests belong to influencing factor tests. Generally, the test substance of the bulk drug is placed in a suitable container (such as a weighing bottle or a petri dish) and spread into a thin layer ≤5mm thick, and the loose bulk drug is spread into a thin layer ≤10mm thick for testing. For oral solid preparation products, generally use the smallest preparation unit with the inner packaging removed, and disperse into a single layer under suitable conditions. If the test result is not clear, two additional batches of samples should be tested.

Ⅱ. Temperature and humidity test of medicine in the stability chamber

1. High temperature test

The test product is placed in a sealed clean container, placed in the stability chamber at 60°C for 10 days, and samples are taken on the 5th and 10th days to test the relevant indicators. If the test product changes significantly, perform the test in the same method at 40°C in the stability chamber. If there is no significant change at 60°C, 40°C test is not necessary.

2. High humidity test

The test product is placed in a constant humidity airtight container, placed at 25℃, RH70%±5% for 10 days, and samples are taken for testing on the 5th and 10th days. The test items should include moisture absorption and weight gain items. If the weight gain by moisture absorption is more than 5%, the test should be carried out in the same way at 25℃ and RH75±5%; if the weight gain by moisture absorption is less than 5%, and other inspection items meet the requirements, the test shall not be carried out. Liquid preparations may not be subjected to this test.

Guangdong Yuanyao Test Equipment Co., Ltd. focuses on the R&D and production of drug stability test chamber, and provides the most suitable solution according to the actual needs of customers. We support various non-standard custom requirements, including dimensions, specific test conditions, control systems, etc. We provide software systems and stylus printers that comply with FDA 21 CFR part 11 standards, and customers can print real-time test curves. The controller is equipped with R232/R485 communication interface, which can be connected to a computer to operate the machine.