Run time for impurities in drug product [August 6, 2004]
Posted: Sun Aug 29, 2004 6:29 pm
By Ina on Friday, August 6, 2004 - 05:05 pm:
Greetings,
Do you have knowledge of any rule according to FDA, ICH, HPB, or other, concerning the run time for HPLC quantification of the impurities in a drug products?
How long the run time should be?
Is it related to the retention time of the API in the sample?
Thank you
-------------------------------------------------------------------------------------------------------
By David Blais on Monday, August 9, 2004 - 08:31 am:
Ina,
As far as I know, there is no rule concerning the runtime. Every method is different, so a blanket rule would not be applicable. As long as you are consistent from analysis to analysis, you should not have any problem. If you need to drastically change the runtime, just make sure it is clearly documented.
-------------------------------------------------------------------------------------------------------
By JM on Tuesday, August 10, 2004 - 05:31 am:
Run the method till your last impurity eluts. it is as simpls as that!!!!
-------------------------------------------------------------------------------------------------------
By ina on Thursday, August 12, 2004 - 02:38 pm:
Hello David and JM,
Thank you for yours helpful replies.
Ina
-------------------------------------------------------------------------------------------------------
By HW Mueller on Wednesday, August 18, 2004 - 01:56 am:
Sorry for the late reply, but the dates of the various chains are all mixed up, so I didn´t find this earlier.
But: how do you know that all your impurities elute? TLC could help here also. How do people do mass balances on tiny amounts of samples? Or do you just use a definition like "impurities according to HPLC..."?
-------------------------------------------------------------------------------------------------------
By JM on Monday, August 23, 2004 - 09:17 am:
No single method can absolutly estimate the total impurities ( Inorganic, organic, solvents, water, polymorphic impurities ).
At the time of HPLC method development, The run time for impurity estimation is finalise after varifing it with gradient run with increasing solvent strength to 100 % organic. Accordingly the gradient or isocratic run time normally decided keeping in mind the last peak.This approach is good for impurities , which are detectable by the detector being used or varify by universal detectors.
Greetings,
Do you have knowledge of any rule according to FDA, ICH, HPB, or other, concerning the run time for HPLC quantification of the impurities in a drug products?
How long the run time should be?
Is it related to the retention time of the API in the sample?
Thank you
-------------------------------------------------------------------------------------------------------
By David Blais on Monday, August 9, 2004 - 08:31 am:
Ina,
As far as I know, there is no rule concerning the runtime. Every method is different, so a blanket rule would not be applicable. As long as you are consistent from analysis to analysis, you should not have any problem. If you need to drastically change the runtime, just make sure it is clearly documented.
-------------------------------------------------------------------------------------------------------
By JM on Tuesday, August 10, 2004 - 05:31 am:
Run the method till your last impurity eluts. it is as simpls as that!!!!
-------------------------------------------------------------------------------------------------------
By ina on Thursday, August 12, 2004 - 02:38 pm:
Hello David and JM,
Thank you for yours helpful replies.
Ina
-------------------------------------------------------------------------------------------------------
By HW Mueller on Wednesday, August 18, 2004 - 01:56 am:
Sorry for the late reply, but the dates of the various chains are all mixed up, so I didn´t find this earlier.
But: how do you know that all your impurities elute? TLC could help here also. How do people do mass balances on tiny amounts of samples? Or do you just use a definition like "impurities according to HPLC..."?
-------------------------------------------------------------------------------------------------------
By JM on Monday, August 23, 2004 - 09:17 am:
No single method can absolutly estimate the total impurities ( Inorganic, organic, solvents, water, polymorphic impurities ).
At the time of HPLC method development, The run time for impurity estimation is finalise after varifing it with gradient run with increasing solvent strength to 100 % organic. Accordingly the gradient or isocratic run time normally decided keeping in mind the last peak.This approach is good for impurities , which are detectable by the detector being used or varify by universal detectors.