Thanks for the advice, I'm pretty sure the regex runs pretty quick - the reason being if I only run a couple profiles (20) the whole routine runs at 0.07 seconds per profile. However if I run a large number (300+) it slows down to ~1.0 seconds per profile (average). I assume this means that something with initializing/re-allocating memory to the hash is what is slowing me down, not the regex.

Either way I took your advice and removed some unnecessary parts of the regex. But it still runs at approx the same speed.