Figure 4.
Long-term stability profiles of Salk IPV formulated in thin silk fibroin films. Formulated IPV films containing 2.4% (w/v) silk fibroin, 5% (w/v) sucrose, 10 mM MgCl2, 10 mM citrate-phosphate buffer and IPV (4 DU, 0.8 DU, 3.2 DU for types 1, 2, and 3, respectively) were stored in glass vials at 4°C, 25°C, 37°C and 45°C. At pre-determined storage durations, films were removed, reconstituted in buffered saline, and assayed via ELISA to determine residual D-antigen content for (A) type 1, (B) type 2, and (C) type 3 poliovirus strains. IPV vaccine (IPOL®; Sanofi-Pasteur, Swiftwater, PA) was also stored at 45°C for stability comparison. Displayed are mean D-antigen recoveries (n=3) at each storage temperature compared to 4°C recovery. (D) Films (n=3) stored at room temperature had D-antigen recovery of 73%, 85%, and 94% after 144 weeks for type 1, type 2, and type 3, respectively.