Structure and pharmaceutical formulation development of a new long-acting recombinant human insulin analog studied by NMR and MS.

A monomer structure of a novel human insulin analog A22S-B3K-B31R (SK3R) has been characterized by NMR in water/acetonitrile solution and compared with the structure of human insulin (HIS) established in the same medium. The composition of the oligomer ensemble for neat insulins in water was qualitatively assessed by monitoring, derived from NMR experiment, translational diffusion coefficient Dix10-10m2s-1, whose value is a population averaged of individual coefficients for species in oligomeric ensemble. Nanospray ESI/MS experiment was used to establish the masses of oligomers in pharmaceutical formulation of the SK3R insulin. The pharmacodynamic data were established and compared to insulin glargine characterized by the same profile of action in diabetics. The oligomerization process of insulin during development of pharmaceutical formulation with routinely used excipients has been studied using translation diffusion coefficient Dix10-10m2s-1 established in water solution. These properties were compared with those of human insulin (HIS) which is a standard reference for novel recombinant insulins.