High-performance liquid chromatographic analysis of nitroglycerin ointment

The assay of ointments containing nitroglycerin is described. Sample preparation by direct dissolution in warm dimethyl sulfoxide appeared to be more accurate than extraction. Anisole was used as an internal standard. Chromatographic conditions included a C18 microporous silica column and a methanol-water mobile phase (40:60). Detection of 215 nm was superior to detection at 254 nm.