Hi, I am doing the HPLC API Impurity Method Transfer to the contract lab.
As per method transfer protocol i made six samle preparations from a single lot of API sample, but Impurity xyz % RSD (six impurity preps) failed 17% (spec 15%).
Interesting thing here is only %RSD of impurity xyz failed but imprity xyz is still within the spec 0.2% (spec. is <0.25%) as per Certificae of Analyis (COA).
Should i initiate the oos investigation ?
or Repeat the whole testing by making six preps and if % RSD passes then just mention in the method trasfer report and labnotebook that %RSD WAS NOT ACHIEVED, CAUSES UNKNOWN, SO TESTING REPEATED.
i think impurity sample %RSD Failure is not an OOS investigation. so i should not initiate oss investigation. What do you think???