Glucocorticoid steroids work by suppressing various aspects of the human immune system in conditions where hyperactivity can cause poor health through allergies, inflammation and autoimmune dysfunction. Betamethasone dipropionate belongs to this class of steroids. It is used for its high potency as an anti-inflammatory and immunosuppressant in the treatment of diseases such as eczema, dermatitis and psoriasis. Betamethasone dipropionate is classified as a ‘super-potent’ steroid in the treatment of psoriasis in comparison with betamethasone valerate (another common analogue of betamethasone) which is rated as upper mid-strength. This application brief describes the use of a Quasar C18 column for the analysis of betamethasone dipropionate in accordance with the official USP monograph.