The dissolution studies of both formulations were conducted using USP apparatus 2 at 50 rpm with 1000 mL of phosphate buffer solution ( pH , 6.8 ) at 37C 0.5 C. Bioequivalence was defined per Korean Food and Drug Administration 's regulatory criteria as 90 % CIs of the geometric mean test/reference ratios of AUC0-t and Cmax within the range of 0.8 to 1.25 .