Recombinant Human Albumin - characterization and stability studies using light scattering techniques
During the development of an active pharmaceutical ingredient (API), it is important to design a formulation that provides adequate stability for long term storage. A liquid formulation is an easy and economical way to handle the product during manufacture and is very convenient for the end user. Recombinant Human albumin (Recombumin® and Albucult®) have been developed to aid in the development of liquid formulations for unstable API’s.
Recombumin is produced by Novozymes Biopharma UK Ltd, and is a saccharomyces cerevisiae yeast- derived protein. This is structurally identical to human serum albumin (HSA). Recombumin itself is formulated at pH 7 and has been shown to have a shelf life of greater than 5 years at 5°C [1].
Both Albucult and Recombumin have been studied and some of the results from the study are presented in the application notes below.
Application notes:
Stability as a function of pH This application note shows how dynamic light scattering (DLS) and gel permeation chromatography (GPC/SEC) were used to study the stability of Recombumin over a range of pH conditions.
Thermal stability The thermal stability of Recombumin was studied over a range of pH conditions by following its unfolding and aggregation. This knowledge allowed determination of the most appropriate pH range for this molecule to provide a stable liquid formulation.
Detection of small oligomeric species The resolving and detection capabilities of size exclusion chromatography light scattering (SEC-LS) and dynamic light scattering (DLS) were used to measure small quantities of oligomers. Mixtures of alcohol dehydrogenase (ADH), 150kDa, and human serum albumin monomer, 65kDa, (Albucult, Novozymes Biopharma UK) were measured to determine the limit of detection.
Interactions at high concentration Inter-molecule and molecule-solvent interactions at concentrations as low as 5mg/mL can change the apparent size determined by dynamic light scattering (DLS) [1]. These interactions are sometimes referred to as virial effects, and depend on both the protein as well as the suspending buffer. Appropriate sample preparation can ensure the true size is measured.
Ref [1 ] “Investigating the stability of recombinant human serum albumin under a range of pH conditions with both time and temperature”
Poster presentation by Mr Karl Nicholls, May 2010, BPI Europe 2010, Vienna - Austria
