Surfactant Impact on Interfacial Protein Aggregation and Utilization of Surface Tension to Predict Surfactant Requirements for Biological Formulations

Abstract

Biological drug products are formulated with excipients to maintain stability over the shelf life of the product. Surfactants are added to the drug product to stabilize air–water interfaces known to induce protein aggregation. Early formulation development is focused on maintaining protein conformation and colloidal stability over the course of the drug product shelf life but rarely considers stability through dose preparation and administration. Specifically, intravenous (IV) bag preparation exposes the therapeutic protein to a different solution environment concurrently diluting the stabilizing excipients that had been added to the drug product formulation. Mixing in IV bags can generate dynamic changes in the air–water interfacial area known to cause protein aggregation if not sufficiently protected. Therefore, understanding the surfactant requirements for drug product end-to-end stability in early formulation development provides critical information for a right-first-time approach to drug product formulation and robust clinical preparation. The goal of these studies was to understand if interfacial properties of proteins could predict surfactant formulation requirements for end-to-end stability. Specifically, the interfacial properties of five proteins were measured in 0.9% saline and 5% dextrose. Furthermore, shaking studies were conducted to identify the minimum surfactant concentration required to prevent subvisible and visible particle formulation in each diluent. The impact of surfactant type and concentration on particle generation and size was explored. A mathematical model was generated to predict the minimum surfactant concentration required to prevent interface-driven aggregation in each diluent based on the change in surface pressure upon exposure of the protein to the interface. The model was tested under typical IV-preparation conditions with experimental output closely matching the model prediction. By employing this model and better understanding the role of surfactants in interfacial stability, drug product development can generate robust end-to-end large molecule formulations across shelf life, dose preparation, and administration.

Effects of Transportation of IV Bags Containing Protein Formulations Via Hospital Pneumatic Tube System: Particle Characterization by Multiple Methods

“…In an IV bag, protein molecules can adsorb to the air-water interface and to the inner walls of the bag 70,120 . Because there is typically an insufficient level of surfactant in IV solution to inhibit protein adsorption to interfaces 68,121 , the interfaces will be fully coated with protein films 86,122 . The mechanical shock occurring when the IV bag hits the wall in the PTS receptacle will rupture the films [77][78][79][80][81][82]84,87,108,112 .…”

“…However it is well known that mechanical shock for example, due to dropping or shipping of containers with therapeutic proteins --can cause cavitation that results in protein particle formation and aggregation, as well as oxidation [47][48][49][64][65][66] . Furthermore, dilution of protein products in IV solution typically results in concentrations of excipients (e.g., surfactants) to levels below those that are needed to stabilize proteins [67][68][69] . The diminished protein stability can result in protein aggregate formation 42,52,[67][68][69][70] .…”

“…Furthermore, dilution of protein products in IV solution typically results in concentrations of excipients (e.g., surfactants) to levels below those that are needed to stabilize proteins [67][68][69] . The diminished protein stability can result in protein aggregate formation 42,52,[67][68][69][70] . Moreover, with inadequate surfactant levels in the IV solution, proteins can form films at the air-liquid interface and at solid-liquid interface of the bag walls [71][72][73][74][75][76] .…”

Differential Surface Adsorption Phenomena for Conventional and Novel Surfactants Correlates with Changes in Interfacial mAb Stabilization

“…Protein therapeutics such as monoclonal antibodies (mAbs) have become leading candidates for the treatment of autoimmune diseases, human cancer, and infectious diseases, among other indications. , Due to mAbs’ amphiphilic nature, adsorption of proteins from aqueous bulk solution onto surfaces (air/water, solid/liquid, or oil/water) has recently gained interest in the literature. − Protein molecules are exposed to several interfaces during the manufacturing of the drug substance, processing of the drug product, and transportation, storage, and clinical administration. It has been hypothesized that as proteins adsorb onto surfaces, they can denature, unfold, and aggregate at interfaces, leading to protein particulates and aggregates in the bulk solution. − Aggregates, sub-visible particles, and visible particles are detrimental to a biologic drug product as they can limit product shelf-life, reduce the effective dose of the drug, and potentially implicate an immunological response. − In order to enhance protein stability, protein formulations often containing excipients such as sugars, , salts, , and/or buffers ,, and surfactants − are employed to minimize the undesired interaction of proteins with surfaces.…”

Salt-Induced Dissolution of Protein Aggregates

“…In addition to salts, additives such as surfactants are also known to modulate the protein aggregation kinetics and the resultant aggregate morphologies. − Anionic surfactants such as sodium dodecyl sulfate (SDS) have been in focus for several decades as SDS is a well-known membrane mimetic and micellar SDS is known to destabilize the protein structure, leading to the formation of aggregation-competent intermediates. It is suggested that the “hydrophobic–hydrophilic interface” on the SDS micelles facilitates the destabilization of a protein, although the extent of destabilization depends on the SDS concentration and the protein–SDS stoichiometry, which may augment or inhibit protein aggregation.…”