(Sharecast News) - Specialty pharmaceutical company Diurnal Group announced on Wednesday that its 'Alkindi' product - hydrocortisone granules in capsules for opening - had been granted orphan drug designation in Australia by the Therapeutic Goods Administration, for the indication 'replacement therapy of adrenal insufficiency (AI) in infants, children and adolescents from birth to 18 years old'.The AIM-traded firm said orphan drug designation in Australia provided "significant" benefits, including a waiver of application, evaluation and annual registration fees.Separately, it also announced the grant of its second patent for Alkindi in Australia, number 2014267041, entitled 'Composition Comprising Hydrocortisone' - a pharmaceutical composition-of-matter patent protecting Alkindi's proprietary formulation as a treatment for all forms of AI, which the board aid was in addition to the already granted patent, number 2012338583.The board said the patents afforded in-market protection until 2034, providing a "long and robust" exclusivity position in Australia for Alkindi.Diurnal's marketing and distribution partner in Australia and New Zealand for Alkindi and its second product, 'Chronocort' - modified release hydrocortisone - is Emerge Health, which was currently pursuing registration for Alkindi in those markets.Australia and New Zealand represented "significant" market opportunities for Diurnal, with around 1,750 patients in the territories suffering from paediatric AI and the genetic condition congenital adrenal hyperplasia (CAH), providing an estimated total market opportunity for Alkindi and Chronocort of approximately $10m per annum.Alkindi was already approved and marketed in Europe, and was the first preparation of hydrocortisone specifically designed for use in children suffering from AI, including the related condition CAH."We are pleased to have obtained orphan drug designation for Alkindi in Australia, highlighting the importance of this product as the first specifically developed and licensed replacement therapy of paediatric adrenal insufficiency designed to address the unmet need in these young patients," said Diurnal chief executive officer Martin Whitaker."This continued progress exemplifies Diurnal's ambition to build our marketing and distribution capabilities in high value markets outside our core territories."