Qualification of Working Standards

Hello!

Could you please supply the Guideline Reference to the statement: " Existing working standard can also be used to prepare new working standard if the results of retesting of existing standard are within specified limits".

This is taken from " GUIDELINES FOR RECEIPT AND USAGE OF REFERNCE STANDARDS AND QUALIFICATION AND USAGE OF WORKING STANDARDS".

Many thanks!

Hi…

Working standard is defined as, “A drug substance of established quality and purity as shown by comparison to the reference standards.” This working standard is used for routine analysis.

For your information the working standard is qualified against the pharmacopeial reference standard or certified reference standard. Qualification of a working standard is done by using a verified or validated analytical method and its results are compared with the reference standard.

Please find the below WHO link for your reference purpose

Thanks,

Kamlesh