Impact of electroviscous effect on viscosity in developing highly concentrated protein formulations: Lessons from non-protein charged colloids

Quantifying Protein Shape to Elucidate Its Influence on Solution Viscosity in High-Concentration Electrolyte Solutions

Therapeutic proteins with a high concentration and low viscosity are highly desirable for subcutaneous and certain local injections. The shape of a protein is known to influence solution viscosity; however, the precise quantification of protein shape and its relative impact compared to other factors like charge-charge interactions remains unclear. In this study, we utilized seven model proteins of varying shapes and experimentally determined their shape factors (v) based on Einstein's viscosity theory, which correlate strongly with the ratios of the proteins' surface area to the 2/3 power of their respective volumes, based on protein crystal structures resolved experimentally or predicted by AlphaFold. This finding confirms the feasibility of computationally estimating protein shape factors from amino acid sequences alone. Furthermore, our results demonstrated that, in high-concentration electrolyte solutions, a more spherical protein shape increases the protein's critical concentration (C*), the transition concentration beyond which protein viscosity increases exponentially relative to concentration increases. In summary, our work elucidates protein shape as a key determinant of solution viscosity through quantitative analysis and comparison with other contributing factors. This provides insights into molecular engineering strategies to optimize the molecular design of therapeutic proteins, thus optimizing their viscosity.

Development of syringes and vials for delivery of biologics: current challenges and innovative solutions

INTRODUCTION

Several new biopharmaceutical dosage forms have developed over time, such as lyophilized vial, liquid vial, and liquid prefilled syringe formulations. This review summarizes major pharmaceutical dosage forms and their advantages, disadvantages, and countermeasures against the shortcomings of each formulation. The appropriate combination of active pharmaceutical ingredients, excipients, and containers should be selected for the safe and less burdensome administration to the patients. Finally, we note certain opinions on the future development of not only therapeutic proteins but also gene therapeutics.

AREAS COVERED

This review is to discuss the challenges of the development of dosage forms to improve pharmaceutical stability and how they can be overcome.

EXPERT OPINION

Silicone oil-free syringes are highly preferable for minimizing subvisible particles in the drug. It can be proposed that materials with less protein adsorption property are preferable for the suppression of protein aggregation. It is required to minimize adverse effects of biopharmaceuticals through proper quality control of the drug in a container, based on the understating of physicochemical stability of the protein in solution, the physicochemical properties of the container, and their combinations.

Discovery-stage identification of drug-like antibodies using emerging experimental and computational methods

There is intense and widespread interest in developing monoclonal antibodies as therapeutic agents to treat diverse human disorders. During early-stage antibody discovery, hundreds to thousands of lead candidates are identified, and those that lack optimal physical and chemical properties must be deselected as early as possible to avoid problems later in drug development. It is particularly challenging to characterize such properties for large numbers of candidates with the low antibody quantities, concentrations, and purities that are available at the discovery stage, and to predict concentrated antibody properties (e.g., solubility, viscosity) required for efficient formulation, delivery, and efficacy. Here we review key recent advances in developing and implementing high-throughput methods for identifying antibodies with desirable in vitro and in vivo properties, including favorable antibody stability, specificity, solubility, pharmacokinetics, and immunogenicity profiles, that together encompass overall drug developability. In particular, we highlight impressive recent progress in developing computational methods for improving rational antibody design and prediction of drug-like behaviors that hold great promise for reducing the amount of required experimentation. We also discuss outstanding challenges that will need to be addressed in the future to fully realize the great potential of using such analysis for minimizing development times and improving the success rate of antibody candidates in the clinic.