Ondansetron is a competitive serotonin type 3 receptor antagonist. It is used to prevent nausea and vomiting caused by chemotherapy by reducing the activity of the vagus nerve and blocking of serotonin receptors. Some of the drug’s most common side effects are headaches, constipation, and dizziness. Primesep 200, a reverse phase column, contains embedded acidic ionizable groups and can retain Ondansetron. The method is UV compatible and can be used as a general approach for analyzing similar compounds.