Buffer‐free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions: From protein buffer capacity prediction to bioprocess applications

Abstract

Protein therapeutics, including monoclonal antibodies (mAbs), have significant buffering capacity, particularly at concentrations>50 mg/mL. This report addresses pH-related issues critical to adoption of self-buffered monoclonal antibody formulations. We evaluated solution conditions with protein concentrations ranging from 50 to 250 mg/mL. Samples were both buffer-free and conventionally buffered with citrate. Samples were non-isotonic or adjusted for isotonicity with NaCl or trehalose. Studies included accelerated temperature stability tests, shaking stability studies, and pH changes in infusion media as protein concentrate is added. We present averaged buffering slopes of capacity that can be applied to any mAb and present a general method for calculating buffering capacity of buffer-free, highly concentrated antibody liquid formulations. In temperature stability tests, neither buffer-free nor conventionally buffered solution conditions showed significant pH changes. Conventionally buffered solutions showed significantly higher opalescence than buffer-free ones. In general, buffer-free solution conditions showed less aggregation than conventionally buffered solutions. Shaking stability tests showed no differences between buffer-free and conventionally buffered solutions. "In-use" preparation experiments showed that pH in infusion bag medium can rapidly approximate that of self-buffered protein concentrate as concentrate is added. In summary, the buffer capacity of proteins can be predicted and buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions.

Matching pH values for antibody stabilization and crystallization suggest rationale for accelerated development of biotherapeutic drugs

“…Likewise the successful crystallization of mAb C in an unbuffered system can be explained. In addition, this result supports the observation that mAbs in buffer‐free environments display substantial self‐buffering capacities (stemming from solvent facing aspartate, glutamate and histidine side chains), resulting in stabilization effects (Bahrenburg, Karow, & Garidel, ; Gokarn et al, ). It would be interesting to find out whether the mAb A crystallization is promoted by (a) the increased T m 1 value; (b) the observed T m 2/ T m 3 cooperative unfolding; or (c) by a combination of these two phenomena.…”

High concentration biotherapeutic formulation and ultrafiltration: Part 1 pressure limits

“…43 Some molecules show the opposite behavior, increasing their viscosity with higher ionic strength. 15,38,44 This suggests that attractive forces can play an important role. When these molecules have a small net charge, they can still loosely associate with a larger effective molecule size.…”

“…Some molecules show the opposite behavior, increasing their viscosity with higher ionic strength . This suggests that attractive forces can play an important role.…”

Stability of buffer-free freeze-dried formulations: A feasibility study of a monoclonal antibody at high protein concentrations

“…Dosages for subcutaneous injection are, however, Abbreviation: mAb, monoclonal antibody. 79 generally limited to 1-2 mL. High protein concentrations 80 ()100 mg/mL) are needed to ensure sufficient therapeutic effect 81 in that small volume [5,6].…”

“…In addition all lyophilizates (Table 4). 790 Finally, to help establish the boundaries for developing HC-FDF, 791 we compared the 6-month reconstitution times, HIC main peaks, [27,79,28]. 837 The freeze-drying process and solid-product characteristics 838 introduce additional factors that must be considered, factors such 839 as residual moisture and reconstitution time.…”