Lyophilized protein formulations, molecular

Yoshioka, S. Aso, Y. Kojima, S. Different molecular motions in lyophilized protein formulations as determined by laboratory and rotating frame spin-lattice relaxation times. J. Pharm. Sci. 2002, 91 (10), 2203-2210. 

The PEG could stabilize proteins by two different temperature-dependent mechanisms. At lower temperatures, it is preferentially excluded from the protein surface but has been shown to interact with the unfolded form of the protein at higher temperatures, given its amphipathic nature (57). Thus, at lower temperatures, it may protect proteins via the mechanism of preferential exclusion, but at higher temperatures possibly by reducing the number of productive collisions between unfolded molecules. PEG is also a cryoprotectant and has been employed in Recombinate, a lyophilized formulation of recombinant Antihemophilic Factor, which utilizes PEG 3350 at a concentration of 1.5mg/mL. The low-molecular weight liquid PEGs (PEG 300-600) can be contaminated with peroxides and cause protein oxidation. If used, the peroxide content in the raw material must be minimized and controlled throughout its shelf life. The same holds true for polysorbates (discussed below). 

Duddu, S. ZJiang, G. Dal Monte, P. The relationship between protein aggregation and molecular mobility below the glass transition temperature of lyophilized formulations containing a monoclonal antibody. Pharm. Res. 1997, 14, 596-600. 

S. Yoshioka, Y. Aso, Y. Nakai, and S. Kojima, Effect of high molecular mobility of poly(vinyl alcohol) on protein stability of lyophilized y-globulin formulations, J. Pharm. Sci. 87, 147-151 (1998). 

As described above, the Ti of carbons in protein and excipient molecules can provide important information on the molecular mobility of lyophilized formulations. Similarly, the Ti, of carbons is useful as a measure of molecular mobility. Figure 16 shows the x of methine carbons in a lyophilized formulation containing dextran, calculated from the observed Tip according to equation (5). The x of methine carbon at 60%RH is of the same order as the x i of methine protons described in Section II.B. 

This chapter describes the dependence of the storage stability of lyophilized formulations on the molecular mobility as determined by NMR relaxation measurements, which was described in Section II, focusing on the degradation of small molecular weight drugs via bimolecular reaction and protein aggregation in lyophilized formulations. 

B. Effect of Molecular Mobility on Protein Aggregation during Storage of Lyophilized Formulations... 

S Yoshioka, Y Aso, S Kojima, S Sakurai, T Fujiwara, H Akutsu. Molecular mobility of protein in lyophilized formulations linked to the molecular mobility of polymer excipients, as determined by high resolution solid-state NMR. Pharm Res 16 1621-1625, 1999. 

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