High throughput formulation: strategies for rapid development of stable protein products

A Surrogate for Debye-Waller Factors from Dynamic Stokes Shifts

We show that the short-time behavior of time-resolved fluorescence Stokes shifts (TRSS) are similar to that of the intermediate scattering function obtained from neutron scattering at q near the peak in the static structure factor for glycerol. This allows us to extract a Debye-Waller (DW) factor analog from TRSS data at times as short as 1 ps in a relatively simple way. Using the time-domain relaxation data obtained by this method we show that DW factors evaluated at times ≥ 40 ps can be directly influenced by α relaxation and thus should be used with caution when evaluating relationships between fast and slow dynamics in glassforming systems.

Rescue of misfolded proteins and stabilization by small molecules

Increasing stability of functional proteins by binding small compounds and ions has long been used to extend shelf-life of protein formulations in the pharmacological and biotechnological industry. Likewise, the therapeutic application of small molecules for in vivo recovery and maintenance of structure and function of proteins is steadily increasing. Compounds that can rescue misfolded proteins by stimulating their correct folding and/or the stabilization of native-like conformations in vivo are referred to as pharmacological chaperones. Here we present thermal-shift and isothermal methods for the high-throughput screening of stabilizing pharmacological chaperones for soluble and membrane proteins. The effect of selected hit compounds on the kinetics of protein synthesis is further evaluated by an in vitro transcription-translation rapid translation system. These procedures can be integrated in an interdisciplinary and translational approach for the search of personalized pharmacological chaperones in genetic misfolding diseases.

Parallel screening approach to identify solubility-enhancing formulations for improved bioavailability of a poorly water-soluble compound using milligram quantities of material

In this article, we present a parallel experimentation approach to rapidly identify a solubility-enhancing formulation that improved the bioavailability of a poorly water-soluble compound using milligrams of material. The lead compound and a panel of excipients were dissolved in n-propanol and dispensed into the wells of a 96-well microtiter plate by a TECAN robot. Following solvent evaporation, the neat formulations were diluted with an aqueous buffer, and incubated for 24h. The solubilization capacity of the excipients for the compound at 24h (SC(24h)), was determined by HPLC, and compared with its solubility in the corresponding neat formulations determined by a bench-scale method. The ranking order of solubilization capacity of the five tested formulations for this compound by this microscreening assay is same as the ranking order of the compound solubility in the neat formulations. Several formulations that achieved the target aqueous solubility were identified using the screening method. One of the top formulations, an aqueous solution of the compound containing 20% Tween 80 by weight, increased the compound solubility from less than 2 microg/mL to at least 10mg/mL. In a rat pharmacokinetic (PK) study, the Tween 80 formulation achieved 26.6% of bioavailability, a significant improvement over 3.4% of bioavailability for the aqueous Methocel formulation (p<0.01). The results in the study suggest that this parallel screening assay can be potentially used to rapidly identify solubility-enhancing formulations for an improved bioavailability of poorly water-soluble compounds using milligram quantities of material.