I am currently discussing issues with some coworkers related to column heater use.

What are the regulations concerning column heater use on HPLCs with validated methods? Are they required to validate a method and where can I find these regs?

How can one define method robustness if column heaters aren't used?

If an HPLC is used in a lab that doesn't have a validated HVAC system how can one say that an assay is run at room temperature if room temperature isnt defined because the HVAC system isnt validated?

Your imput is greatly appreciated.

Agilent online course about HPLC Validated methods (To tweak or not to Tweak) suggested +/- 20 C would be considered tweaking and would not require revalidation. That would cover differences in non-controlled lab environment.

What about methods that are being validated in a non-controlled environment? Anonomous (above) covered a method that has been validated and already has specified limited of temperature robustness. A mere method transfer is all that is then required and you can rely on the validated method because its robustness has already been defined, as you say...+/-20degrees C. Not all methods will have a robustness that allows a temperature variance like the one you stated. Therefore, especially if the method is being validated in a non-controlled environment, how can one establish a limit to the allowable temperature vaiances that a method can be run under without the help of a column heater?

Consistant temperature is the main use of a column heater. It is not a matter of it being validated at 40C and want to use it at room temp 20C. That does bring up concerns. But, the main concern when not using a column heater is the variation of temperature through out the run. Will that variation in temperture effect the resolution and area counts? Will it shift peaks enough that you can not identify them?

If you wanted to prove that the method was rugged over a range of temperature, typical of room temperature. Then, you must validate that no significant change happens to the chromotagraphy when the temperature changes.

If you are working in the pharmacutical industry, this issue is addressed in the USP Pharmacopeal Forum under Chromatography {621}. This revision discusses reasonable changes that do not require full validation. It would be important to still show that your method is appropriate for the intended use.

Anonymous on Saturday...

The USP chapter is relavent to USP methods as they are used out of the USP and as they will be tranferred into the laboratory. You still have to define the temperature range within which a method can suitably be run when validating it as a USP or Non-USP method. You can't just assume that if it works at what happens to be room temperature one day that it will work at what may be room temperature another day. You must prove that it can handle the temperature range without sacrificing any quality requirements.

Yes, the USP says that +/-20 degrees Celsius is an acceptable temperature range, but +/-20degrees Celsius from what? What temperature have you defined as the reference point. If you haven't qualified/validated your HVAC you have no defined reference point. If you use no column heater you have no control over temperature variations. If you haven't included a defined temperature variance analysis in the robustness portion of your method validation you do not know at what temperatures you "method is appropriate for its intended use".

So lets play it smart here; use a qualified column heater in conjunction with you method validation, (in the temperature robustness section), and a method can be run under routine use without a column heater, at what is defined as room temperature and with a temperature variance that is defined by the temperature robustness portion of your method validation.

There are so many questions left wide open for auditors to ask if you rely on what may be room temperature one day for the method validation and apply the +/-20 degree Celsius rule for acceptable temperature variations for normal method use. Define and validate according the temperature range. It'll make life easier in the long run.