Pd miditrap g 10 gravity columns

The authors' amphiphilic acrylamide copolymer excipient acryloylmorpholine_77%‐N‐isopropylacrylamide_23% (MoNi_23%) was prepared according to published protocols.^[10] Characterization of MoNi_23% molecular weight and monomer composition can be found in Table S1, Supporting Information. Humalog (Eli Lilly) and pramlintide (BioTang) were purchased and used as received. For zinc‐free lispro, Zinc(II) was removed from the insulin lispro through competitive binding by addition of ethylenediaminetetraacetic acid (EDTA), which exhibits a dissociation binding constant approaching attomolar concentrations (K_{D ≈} 10⁻¹⁸ m).^[20] EDTA was added to formulations (4 equiv. with respect to zinc) to sequester zinc from the formulation and then lispro was isolated using PD MidiTrap G‐10 gravity columns (GE Healthcare) to buffer exchange into water. The solution was then concentrated using Amino Ultra 3K centrifugal units (Millipore) and reformulated with 2.6 wt% glycerol, 0.85 wt% phenoxyethanol in 10 mm phosphate buffer (pH = 7.4). All other reagents were purchased from Sigma–Aldrich unless otherwise specified.