» Tromethamine for Injection is a sterile, lyophilized mixture of tromethamine with Potassium Chloride and Sodium Chloride. It contains not less than 93.0 percent and not more than 107.0 percent of the labeled amount of tromethamine (C₄H₁₁NO₃), and not less than 90.0 percent and not more than 110.0 percent of the labeled amounts of potassium chloride (KCl) and of sodium chloride (NaCl).