How To Handle Primary and Secondary Reference Standards in A Quality Control (QC) Laboratory?
In this article, we’ll learn about multiple requirements/guidelines prescribed by sections 11.17, 11.18, and 11.19 of ICH Q7 to handle primary and secondary reference standards
Learn how to handle other standards including laboratory reagents and standard solutions
Requirements to handle primary reference standards
Section 11.17 of ICHQ7 prescribes primary reference standards that should be obtained as appropriate for the manufacture of APIs. The source of each primary standard must be recorded. Records of each primary reference standards storage and usage should be maintained by the supplier’s recommendations. It is necessary to have primary standards in the QC laboratory for testing and release of materials during manufacturing. The source of such standards has to be documented fully.
The sources generally are from USP or EP. They supply the primary standards as current reference standards (CRS). These primary standards are identified with a specific lot number. For this purpose, you have to visit the respective official website and download the COA. Document this information along with the certificate of analysis. The primary standard gets replaced with fresh slots. There should be a detailed procedure in your sop on handling primary standards. The procedure should describe how frequently the respective website is checked to find out if there is a change in the lot number.
It is necessary to replace the old standard with a new one whenever a new lot is available. Read the usage instructions carefully before using the primary standards. Appropriate storage conditions have to be followed as recommended by the supplier. Some standards may have to be stored at 2 to 8 degrees Celsius or 25 degrees Celsius or in different temperature conditions. Certain standards are hygroscopic and need to be protected from accidental ingress of traces of water unless such standards are stored well protected in a desiccator with active desiccant they can lose their potency. So, it is very important to adhere to the storage conditions as recommended.
Primary reference standards from an officially acknowledged source are normally used without testing if stored under conditions consistent with the supplier’s recommendations. The official standards are already qualified at the source hence it is not required to test once again. They are well elucidated for chemical structure impurities and purity established fully at the source. However, those sources may not provide us with such data for our records. It will be archived at the source site also the standards will not give complete analytical data on the standard. It gives only information on potency or levels of impurities etc. It's also important that they are stored as recommended to avoid any deterioration.