effect of parameter not being part of design, how to evaluate, treat it as covariate or something else

[#1]

We would like to do response surface design for optimization of two formulation factors… we would like to consider compression force as well as it might have an effect, but could we not have it to be part of the design because it may be adjusted differently for different formulations… in that case could we treat compression force as covariate then, and how?

Or what else we could do…?

@Ben_Ingham

[#2 · Accepted solution]

Hi @TM,

For more context, what reason would there be for adjusting the compression force based on the formulation? Is it to ensure you get some form of material/success at the end (i.e. Compression Force of 1 wont work when Factor A is set to 0, but work when set to 10).

Thanks,

Ben

[#3]

Hi @Ben_Ingham ,

Compression force would be adjusted to get acceptable friability, and for different formulations different ranges of compression force might be considered acceptable. However, compression force might be important factor for dissolution, our primary response of interest. We might generate for each formulation samples on two levels of compression force but they maybe won't be always same low and high values for all formulations.