Protein formulation studies to optimise biopharma product’s shelf-life

By Joe Page, PhD, President, Eurofins Advantar Laboratories,

Protein formulation studies begin with a thorough understanding of the clinical requirements for the biopharmaceutical product, including dosage form (liquid or lyophilised), concentration, pH, and long-term stability. The protein under development may lose activity over time or undergo degradation that limits its shelf life. Common pathways of protein degradation include aggregation, deamidation, oxidation, and loss of structural integrity. Based on the sponsor’s required product characteristics and anticipated degradation pathways, multiple formulation candidates are prepared and screened in stability studies.

The optimal pH for a protein’s stability can be determined in pH-stability screening studies with various buffer types and tested for degradation events (deamidation, aggregation, loss of activity, etc.). Antioxidants may be needed if the protein is susceptible to oxidation.

To minimise aggregation, polysorbates may be added to the formulation at low levels. The use of sugars and salts may be needed if the protein is to be formulated at high concentrations. If the dosage form requires ambient temperature storage or is not stable in a liquid formulation, Eurofins Advantar Laboratories can design a lyophilised formulation and lyophilisation cycle.

The formulation candidates are typically screened at real time and accelerated stability. The following analytical tools enable the collection of rapid and accurate results to identify the most stable formulation candidates. The formation of degradation products can be assessed by capillary electrophoresis (CE-SDS) on a SCIEX PA800 or by UPLC on an Agilent 1290. Dynamic light scattering (DLS) on a Wyatt Dynapro can be used as an early indicator of the on-set of aggregation. Size exclusion HPLC with a Wyatt multiangle light scattering detector (MALS) rapidly determines the molecular weight of protein aggregates. Protein deamidation and other events that change the charge of the protein can be monitored by capillary isoelectric focusing (cIEF) on a Protein Simple iCE system. ELISA experiments can be performed with Molecular Devices plate readers to evaluate the protein binding behavior.

For more information, visit: www.eurofins.com/bpt