How to Handle Laboratory Reagents and Standard Solutions Prescribed by Section 11.16 of ICH Q7 Guidelines?
Section 11.16 of ICH Q7 Guidelines
It prescribes laboratory reagents and standard solutions should be prepared and labeled following written procedures. Usage of analytical reagents or standard solutions should be applied by dates appropriately. This is another important section handling of reagents and standard solutions have to be described in detail in the SOP. There is a requirement to indicate the use-by date which means the expiry date of the reagent.
If you are handling primary and secondary reference standards in a QC lab then read about the handling guidelines of ICH Q7 for primary and secondary reference standards
How do we handle this if it is a standard solution or a volumetric solution? The solutions are evaluated with a definite frequency like once a week or so and confirm that the strength of the stated standard is within the acceptance criteria. The general thumb rule is that the strength should be within 10 percent of the prescribed strength always. For example, for a 1.0 normal volumetric solution, the strength should not vary more than 10 percent on either side which means one normal solution can vary between 1.1 on the higher side and 0.9 on the lower side 0.1 is ten percent of one.
So, the SOP should describe this requirement. In the same example as above carry out the standardization every week if the normality varies beyond 1.1 to 0.9. After four weeks as saying the shelf life is used before the date for that particular volumetric solution as three weeks. Because up to three weeks the normality was within 1.1 and 0.9. So, the stability of the volumetric solution is only three weeks.
This is a much simpler approach consider the same approach for all volumetric solutions and assign the use by dates accordingly record all these details fully. As per the laboratory reagents it is recommended to use the supplier’s recommendation as given on the label if it is not a part of the label you may have to get the data from the supplier’s database you cannot give some arbitrary date. There is another way also the use by date may be assigned a minimum of one year again it is assumed that it is fine within one year. A suitability test of the lab reagents could be done after the use-by date.
A simple test to establish the suitability could be for instance, if you have a phenolphthalein indicator prepare a solution and check with sodium hydroxide solution and confirm if the indicator is responding to give a pink color it is a suitability test. Similarly, you can have different types of methods to establish suitability. Use appropriate methods for standardization as per any official compendia. You can use any other standardization procedure as far as it gives at least the same degree of accuracy as the method described in the compendia like USP, EP, or IP. It is recommended to carry out the standardization in triplicate, 3 is the minimum number required for statistical evaluation.
Material safety data sheets (MSDS) for critical sensitive and toxic reagents should be handy while handling. This is required to get complete knowledge about the chemical that is being handled in the laboratory necessary PPEs how to be used while handling the lab reagents or standard solutions. Use always rubber bulbs to pipette out any volumetric or standard solution, never put out with mouth this is a very dangerous practice.