Why we take stability sample only in first batch of any product at the start of Year.
because of the product may not be mfg. in the year ,the sample collection was missed.so we take the 1st batch in the start of the year.
There is a chance of missing to collect samples for stability and after no batch is manufactured it is better to take samples for stability from the first batch.
For suppose Paracetamol prepared 10 batches in 2020 year.
All batches Have same master formula so only first batch performed in stability. Incase Formula or description or any changes to need after changes given to another one batch for stability test but product is same,
Yes, in case of a major change in the master formula or processing steps the sample of this batch should be kept on stability to understand impact of the change(s).
That is why sample of first batch of every product manufactured in the year should be kept on stability.