Product excipients are used to confer a number of desirable properties on the drug substance to maintain or improve stability and facilitate drug delivery. This is especially important for products where the active pharmaceutical ingredient (API) is a recombinant protein. In this study, we aimed to determine if excipients and formulation conditions affect the structure and/or modulate the dynamics of the protein API of filgrastim products.
View Article and Find Full Text PDFWe have previously identified extensive glycation, bound fatty acids and increased quantities of protein aggregates in commercially available recombinant HSA (rHSA) expressed in Oryza sativa (Asian rice) (OsrHSA) when compared to rHSA from other expression systems. We propose these differences may alter some attributes of nanoparticles fabricated with OsrHSA, as studies have associated greater quantities of aggregates with increased nanoparticle diameters. To determine if this is the case, nanoparticles were fabricated with OsrHSA from various suppliers using ethanol desolvation and subsequent glutaraldehyde cross-linking.
View Article and Find Full Text PDFMicroflow digital imaging (MDI) has become a widely accepted method for assessing sub-visible particles in pharmaceutical formulations however, to date; no data have been presented on the utility of this methodology when formulations include opaque vaccine adjuvants. This study evaluates the ability of MDI to assess sub-visible particles under these conditions. A Fluid Imaging Technologies Inc.
View Article and Find Full Text PDFHuman serum albumin (HSA) is a versatile and important protein for the pharmaceutical industry (Fanali et al., Mol. Aspects Med.
View Article and Find Full Text PDFContext: At elevated temperatures, studies have shown that serum albumin undergoes irreversible changes to its secondary structure. Anionic fatty acids and/or anionic surfactants have been shown to stabilize human serum albumin (HSA) against thermal denaturation through bridging hydrophobic domains and cationic amino acids residues of the protein.
Objective: As albumin can readily interact with a variety of liposomes, this study proposes that cardiolipin delivered via 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes can improve the thermal stability of recombinant HSA produced in Saccharomyces cerevisiae (ScrHSA) in a similar manner to anionic fatty acids.
Previous studies have demonstrated that liposome-protein interactions can result in changes to the thermal stability of the protein. We utilized far-UV circular dichroism spectropolarimetry and fluorescence spectroscopy to investigate the interaction of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes with two recombinant human serum albumins (rHSA). We demonstrate that rHSA expressed in Oryza sativa (OsrHSA) has improved secondary structure thermal stability compared to rHSA expressed in Pichia pastoris (PprHSA).
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