Maninder S. Hora

Vaccines with the MF59 Adjuvant Do Not Stimulate Antibody Responses against Squalene

ABSTRACT Squalene is a naturally occurring oil which has been used in the development of vaccine adjuvants, such as the oil-in-water emulsion MF59. In past years, by use of noncontrolled and nonvalidated assays, a claim was made that antisqualene antibodies were detectable in the sera of individuals with the so-called Gulf War syndrome. Using a validated enzyme-linked immunosorbent assay for the quantitation of immunoglobulin G (IgG) and IgM antibodies against squalene, we demonstrated that antisqualene antibodies are frequently detectable at very low titers in the sera of subjects who were never immunized with vaccines containing squalene. More importantly, vaccination with a subunit influenza vaccine with the MF59 adjuvant neither induced antisqualene antibodies nor enhanced preexisting antisqualene antibody titers. In conclusion, antisqualene antibodies are not increased by immunization with vaccines with the MF59 adjuvant. These data extend the safety profile of the MF59 emulsion adjuvant.

Controlled release of recombinant insulin-like growth factor from a novel formulation of polylactide-co-glycolide microparticles

The purpose of the current study was to develop a controlled-release delivery system for recombinant insulin-like growth factor (rhIGF-I). Polylactide-co-glycolide (PLG) microparticles with entrapped rhIGF-I were prepared by a novel emulsion based solvent evaporation process. Microparticles with two loading levels of rhIGF-I were prepared (4 and 20% w/w). The integrity of released rhIGF-I was characterized by RP-HPLC, SDS-PAGE and a bioactivity assay. In vitro and in vivo release profiles of rhIGF-I from these microparticles were also evaluated. Reproducible batches of microparticles with 4% and 20% w/w loading of rhIGF-I were prepared, with excellent encapsulation efficiency (81 and 85% of total protein respectively entrapped). The protein retained integrity after the microencapsulation process as evaluated by RP-HPLC, SDS-PAGE and bioactivity assay. The in vitro profiles exhibited a significant burst release of rhIGF-I (20-30%), followed by controlled release of protein for up to 28 days. A similar level of burst release was observed in vivo, followed by controlled release of protein for 14-18 days. In addition, there was a surprisingly close correlation between in vitro and in vivo release rates. PLG microparticles with entrapped rhIGF-I are a promising delivery system which may allow rhIGF-I to be used for a broad range of therapeutic indications.

Stabilisation of biopharmaceutical products and finished product formulations

This chapter overviews the stabilization of protein-based biopharmaceuticals. Finished biopharmaceutical products must have the required stability from a clinical and regulatory point of view. Furthermore, the stability profile should cover the manufacturing and marketing cycles of the product to minimise costs. The major routes by which proteins may be degraded are outlined. A brief description of biopharmaceutical production processes is provided to acquaint the reader with issues relating to stabilisation during processing. The basic principles of how in-process material and fmished product may be stabilized are presented. Finally, a table of major constituents in approved biopharmaceuticals is included at the end of the chapter to illustrate how stabilisation principles have been put to practice to date.