Why should the Carbomeergel be water-free to process fluphenamic acid? If I do not anhydrous fluphenamic acid with the unguator in Carbomeergel this also does not give precipitation.

Since I never tried this preparation mode I can't contradict you  . But Fluphenaminzeuur is in the total context of the cream a competitor together with Carbomer for the present base. Normally, fluphenamic acid reacts with the base and the gel flows into less or more degree. This requires an additional amount of base to be added but as long as not all the fluphenamine is converted into its salt, the base does not react with the carbomeer. On the instantaneous of reaction with Carbopol the viscosity will rise. But then all the fluphenamine is converted to its salt, which is absorbed much less well.  

In Water-free middle do not enter acid base reactions. The carbomer swells through the presence of glycerin.