First of all, measurement fo the pH of a powder is preposterous. The whole "concentration of H+" (or "inverse concentration of OH-") per se does not even arise until the compounds are in solution, whence they are ionized into H+ & Cl- or Na+ & OH- for instance..
As such, it is not necessary to think of the dry basing issue in terms of the active ingredient. You just need to be confident that all grains of the active ingredient have adequate opportunity to come into contact with the base. That is the logic behind adding roughly equal volumes of dry base to pill mass. You must bear in mind that when someone, for instance, has 100 30mg pills, there may be 3g of active ingredient, but the after all the fillers the total pillmass may be 10-20x more than that. Put another way, if I had a 30mg pill the size of a lightbulb with 500g filler I would NOT still put 30mg base in there, it would be more.. In all cases, an excess of base vs. active ingredient is used.
As for the paracetamol, I don't know. Read the original Tetra Trap thread.