Excipients are a substance that is often added to protein formulations to serve as a medium for the proteins or active substance in the formulation. While commonly perceived as inert and just a supplement to improve the formulation or become a diluent, adding excipients have sometimes created a reaction of the ingredients in the formulation and according to the NPS Medicinewise article*, such reactions have resulted in various reactions in patients as well.
In the upcoming weeks, we are proud to announce the release of our latest application note regarding concentration dependence in protein viscosity. In this app note, Dr. Stacey Elliott gathered viscosity data for Bovine Gamma Globulin (BgG) formulations over the full concentration range, including therapeutic levels ≥ 100 mg/mL, using the VROC®Initium. The solution buffer included sucrose which is a common additive to enhance stabilization during freeze-drying and storage. Relative viscosity versus concentration curves were fit with the Ross-Minton equation which is a frequently used analysis tool for protein formulations.
To view application note, click below!
According to Cell Press, "Royal jelly is produced in [two different] glands of worker bees, one that produces the protein in a neutral pH and one that produces fatty acids that can reduce said pH when the two secretions" come together (Cell Press).
For a honeybee, royal jelly is a crucial diet for the first couple days for all bees. And for honeybee larvae to become queen, the larvae must be fed and be surrounded by royal jelly for it to morph successfully. However, because queen larvae, "are too big to fit into the cells of the hive's honeycomb," they are able to hang upside down in the queen's cell anchored with the royal jelly (Cell Press). So, what allows this royal jelly to acquire these properties?
Turns out, royal jelly is not always thick and sticky. In a recent study, researchers proposed that the viscosity of a royal jelly were dependent the particle size of a protein found in royal jelly (known as royalactin, or MRJP1) was directly correlated to the pH level found inside. The study conveyed that there was a noticeable size difference within the MRJP1 jelly when exposed to a purifier at pH 4 and at neutral (pH 7). For instance, "Most purification protocols are standardized at pH 7, [which yielded] a strange, runny consistency [within the jelly]" whereas when maintained between pH 4 and pH 5, the viscosity of the jelly seemed gelatinous and almost adherent (Cell Press). The precise pH affects the overall viscosity of royal jelly, which is an essential component in providing the optimal environment for the queen bee to develop in her early stages. If the pH levels were outside 4~5, the royal jelly would lose its heavy, sticky properties and would not be able to hold the queen larvae.
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.
Do you subconsciously dread the first drop of ketchup out of its bottle? Have you noticed the inconsistent flow in the substance as you try to coax the ketchup out, only to have a huge gush of flow when you realize you have coaxed it a little too well?
Bovine Serum Albumin (BSA) is a globular protein extracted from cow’s blood. Due to its low-cost, stability and availability, BSA is widely used as a protein concentration standard.
Read more about what major applications of BSA include:
The exact mechanism by which Arginine molecules affect protein molecules in solution is unclear. Nonetheless, its benefits increasing solubility and controlling viscosity have spread out its application in biopharma formulations, specially for high concentration antibody solutions.
In our application note, we examine the effect of concentration on the viscosity of dilute solutions of L-Arginine in water and PBS. Additionally, we study the Intrinsic Viscosity of this solutions to better understand molecular size and solubility in dilution.
We are excited to announce an upcoming trip to Seoul, Korea by RheoSense CEO & Founder, Dr. Seong-Gi Baek. He will be in Korea to present at two seminars organized by our distributor, Insung Chroma-Tech.