Surface adsorption of recombinant human interferon-γ in lyophilized and spray-lyophilized formulations

✍ Scribed by Serena D. Webb; Stephen L. Golledge; Jeffrey L. Cleland; John F. Carpenter; Theodore W. Randolph

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 165 KB
• Volume: 91
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.10135

✦ Synopsis

Recombinant human interferon-gamma (rhIFN-gamma) was lyophilized or spray-lyophilized in 9.5% trehalose, +/- 0.12% polysorbate 20 in 10 mM potassium phosphate, pH 7.5. We measured recovery of soluble protein after spraying, freeze-thawing, and drying and reconstitution. Infrared spectroscopy showed rhIFN-gamma secondary structure to be native-like in all dried powders. Powders were characterized using electron spectroscopy for chemical analysis, time-of-flight secondary ion mass spectroscopy, X-ray diffraction, and gas adsorption isotherms. rhIFN-gamma adsorbed at air/liquid interfaces during spraying, and to ice/liquid interfaces during lyophilization. The concentration of rhIFN-gamma at ice/liquid interfaces was approximately one-fourth that adsorbed at air/liquid interfaces. Addition of 0.12% polysorbate 20 reduced the concentration of rhIFN-gamma at both interfaces. Time-of-flight secondary ion mass spectroscopy detected polysorbate 20 on surfaces of lyophilized powders. Lyophilized samples dried more slowly but reconstituted more quickly than spray-lyophilized samples. rhIFN-gamma aggregated after nebulization, but aggregation decreased in 0.12% polysorbate 20. Addition of 0.12% polysorbate 20 reduced protein surface adsorption and decreased but did not completely prevent aggregation. Insignificant aggregation occurred after exposure to ice/liquid interfaces, but subsequent drying and reconstitution caused aggregation. The majority of the aggregation is due to adsorption at air-liquid and solid-air interfaces formed during spray-lyophilization or lyophilization.