cytarabine was patented in 1960 and approved for medical use in 1969. it is on the world health organization's list of essential medicines, the most effective and safe medicines needed in a health system. the wholesale cost in the developing world is about 4.27 to us$5.70 per 500 mg vial. this dose in the united kingdom costs the nhs about 50.00 while the liposomal form is 1,223.75 per 50 mg vial.