*, the estimate is based on the total peak area of detectable peptides in the identified proteins as compared to the total peak area of detectable peptides in the 0.1 µg/mL load of BSA standard on the Coomassie blue stained gel (molar ratio). BSA has a total peak area of 3.93×10⁷, the molar ratio was then converted to mass ratio (ng/mg) based on the MW difference. The detection of 0.1 µg/mL of BSA in 20 mg/mL MK-1454 API is equivalent to 5 ng/mg API.