Arginine is reported to be capable of reducing aggregation and viscosity, increasing the solubility of the protein in the liquid form (1). Little is reported regarding the impact of arginine in lyophilized formulations (2). The aim of this study was to investigate the behaviour of arginine in lyophilized high concentration protein formulations.
A DOE approach was used to select the composition of the formulations and to maximize the critical temperatures using a Response Optimizer provided by the Minitab® Software. The effect of formulation components on the critical temperatures, Tg’ (Modulated DSC) and Tc (FDM), was observed. Optimization of the lyophilization process was conducted using a lyo-modelling approach for selected formulations. Lyophilized formulations were further characterized by determining the relationship between the BET specific surface area and the macroscopic visual appearance.
Results showed that the mixture DOE and resulting surface response model was capable of predicting the formulation Tg’ and, hence informed formulation design. Tg’ increased at high protein concentrations and depressed by the presence of excipients. Formulations containing high protein concentrations showed multiple micro-collapses rather than gross collapse behaviour. This effect was reduced in presence of arginine. Following lyophilization, products containing arginine showed an improved product appearance in comparison with the corresponding sucrose rich samples. Optimization of the lyophilization process allowed a reduction in primary drying time by 11h. Lyophilized formulations, containing arginine, showed a significant reduction in specific surface area in comparison with the corresponding sucrose rich formulations.
Arginine was shown to depress critical temperatures, to improve lyophilized formulation macroscopic appearance and reduce its specific surface area.
1. Ohtake S, Kita Y, Arakawa T. Interactions of formulation excipients with proteins in solution and in the dried state. Advanced drug delivery reviews. 2011;63(13):1053-73.
2. Stärtzel P, Gieseler H, Gieseler M, Abdul‐Fattah AM, Adler M, Mahler HC, et al. Freeze Drying of l‐Arginine/Sucrose‐Based Protein Formulations, Part I: Influence of Formulation and Arginine Counter Ion on the Critical Formulation Temperature, Product Performance and Protein Stability. Journal of pharmaceutical sciences. 2015;104(7):2345-58.