One of the challenges of creating monoclonal antibody (mAb) injectable drugs is optimizing formulation. A good formulation has to have a high concentration of stable mAb’s for high efficacy. There are a variety of factors that can affect stability of these mAb’s, temperature, shear forces, pH, and even concentration. When proteins become, unstable and denature they can increase the viscosity of your formulation. Using a simple modified parallel plate demonstration, we can visualize why denatured proteins increase viscosity.
In this clip, the rubber band balls represent proteins in their folded state. They are resting on a plate with a slight slope. When the second plate is placed on top the shear force applied by the top plate is enough to create “flow”. Represented by the top plate sliding. This would be the low viscosity folded state of the protein formulation.
In this clip, the rubber bands representing the proteins have denatured/unfolded and proteins or rubber bands in our case are able to tangle and interact. In this instance when the top plate is placed on top the shear force is not enough to create “flow” therefore the denatured proteins have greater resistance to flow or higher viscosity.
In reality, the changes in viscosity that occur when proteins denature can be quite small and difficult to detect with conventional methods, therefore it is important to have a viscometer that can accurately and repeatedly take these precise measurements. All of our viscometers, VROC® Initium, m-VROC®, and microVISC™, have a resolution of 0.2 cP and are capable of detecting these miniscule changes in viscosity. Are you using viscosity to optimize your formulations? See what else our viscometers can do to help your research.