They are the same amounts of hydro and APAP if the Endo 10
is E712. If the ENDO 10
then the content is 10
/650 so 325 MORE mg of APAP. The M523 are always 10/325. Quality wise you may be right may not on the difference. I have never used the Endo, so can't comment. I found the M523 to be adequate.....as they are the equivilent of Norco-10/325. Strictly from a technical pov, the only other difference would be whether you posses a legal prescription for either of them.