Does anyone here combine different powders into the same gel cap such as L-Theanine and Caffeine?

*Warning, don't do anything like this without researching first as you should always know what your dose is even when taking harmless substances. I'm still researching if this is even possible.

I have a digital scale and a gel capping machine and since I use 200mg caffeine and 200mg Theanine, I thought it may save some time to pre-mix the two powders before capping into the same cap assuming they would mix properly?

http://en.wikipedia.org/wiki/Powder_mixture is very informative as to how powders mix. Smart Powders seems to have the same consistency but I didn't want to risk having inaccurate doses... I like to know exactly what I am getting.

Wondering if anyone had any advice or had any other shortcuts for combining nootropics into the same gelcaps. Thx