P1-185

P1-185, also known as progesterone 3-"O"-(-valine)-"E"-oxime or as pregn-4-ene-3,20-dione 3-"O"-(-valine)-"E"-oxime, is a synthetic progestogen and neurosteroid and an oxime ester analogue and prodrug of progesterone (and by extension of allopregnanolone). It was developed as an improved water-soluble version of progesterone such that it could be formulated as an aqueous preparation and easily and rapidly administered intravenously as a potential therapy for traumatic brain injury. However, the chemical synthesis of P1-185 was described as somewhat challenging, so oxime conjugates of progesterone of the C20 instead of C3 position, such as EIDD-1723 and EIDD-036, have since been developed.