Diurnal has developed a ‘delayed and sustained release therapy’ to deliver hydrocortisone in a manner that mimics the normal physiological circadian rhythm. This clearly defined rhythm, with high levels in the morning and low levels at night, is lost in patients with adrenal insufficiency. The product, has received two related Orphan Medicinal Product designations from the European Medicines Agency, which affords ten years of market exclusivity after the grant of a marketing authorisation in Europe.