title: Dye-salt formation as a general method for colorimetric determination of antihistaminics. I. The use of methyl orange for the determination of chlorphenamine, diphenhydramine and chloropyramine in pharmaceutical preparations.
mesh_terms: D001593:Benzyl Compounds / Q000032:analysis; D002744:Chlorpheniramine / Q000032:analysis*; D003124:Colorimetry / Q000379:methods*; D004396:Coloring Agents; D004155:Diphenhydramine / Q000032:analysis*; D005029:Ethylenediamines / Q000032:analysis*; D006634:Histamine H1 Antagonists / Q000032:analysis*; D011725:Pyridines / Q000032:analysis*; D012492:Salts
chemical_list: D001593:Benzyl Compounds; D004396:Coloring Agents; D005029:Ethylenediamines; D006634:Histamine H1 Antagonists; D011725:Pyridines; D012492:Salts; D002744:Chlorpheniramine; D004155:Diphenhydramine