Preparation of a microcrystalline suspension formulation of LysB28ProB29‐human insulin with ultralente properties

The monomeric analogue, LysB28ProB29‐human insulin (LysPro), has been crystallized using similar conditions employed to prepare extended‐acting insulin ultralente formulations. In the presence of zinc ions, sodium acetate and sodium chloride, but without phenolic preservative, LysPro surprisingly forms small rhombohedral crystals with similar morphology to human insulin ultralente crystals with a mean particle size of 20 ± 1 µm. X‐ray powder...