Procedure Proceed as directed for Procedure in the Assay under Acetaminophen Capsules. Calculate the quantity, in mg, of CH9NO, in the portion of Tablets taken by the formula: 10,000 in which C is the concentration, in mg per mL, of USP Aceta- minophen RS in the Standard preparation, and ru and rs are the aceta minophen peak responses obtained from the Assay preparation and the Standard preparation, respectively.