Guaifenesin, a highly water-soluble active (50 mg/mL), classified as a BCS class I drug.Owing to its poor flowability and compressibility, formulating tablets especially high-dose one,may be a challenge. Direct compression may not be feasible. Bilayer tablet technology appliedto Mucinex®, endures challenges to deliver a robust formulation. To overcome challengesinvolved in bilayer-tablet manufa...