About Mucinex Extended-Release Bi-Layer Tablets contain an immediate-release layer on one side and an extended-release layer on the other side. Relieves the following symptom: Chest Congestion Chest Congestion Product Highlights: 12 Hour Dosing 12 Hour Dosing Day Time Day Time Night Time Night Time Active Ingredients Directions Adults and children 12 years of age and over: 1 or 2 tablets every 12 hours; do not exceed 4 tablets in 24 hours. Children under 12 years of age: Do not use. - Do not crush, chew, or break tablet. - Take with a full glass of water. - This product can be administered without regard for the timing of meals.