What is "ultralente"

'Ultralente insulin is a long acting form of insulin. It has an onset of 4 to 6 hours, a peak of 14 to 24 hours, and a duration of 28 to 36 hours. This, along with lente form of insulin, was discontinued in the US by Eli Lilly and Company in 2005. One of the reasons for discontinuation was declining use due to physicians favoring NPH insulin and other basal insulin drugs.