ABSTRACT
Many proteins in aqueous solution are susceptible to interfacial denaturation and precipitation during mechanical agitation. With the large number of protein parenteral products currently in research or clinical testing, it is important not only to understand this denaturation process but also to develop effective methods for stabilizing the products. Surfactants, such as Polysorbate 80 or sodium dodecyl sulfate (SDS), are frequently used to stabilize parenteral products. While it is a commonly accepted technique, little has been published about the precipitation and stabilization processes in general. We describe the stabilization of antibody products in solution by preferential adsorption of a water-soluble, non-ionic surfactant at the air-liquid interface. Data are presented from antibody and immunotoxin solution shake studies and surface tension measurements to support the utility of surface tension measurements in formulation design.
Subject(s)
Drug Design , Protein Denaturation , Surface Tension , Adsorption , Chemistry, Pharmaceutical , Drug Stability , Surface-Active AgentsABSTRACT
A rapid assay for recombinant leukocyte A interferon has been developed that includes a small immunosorbent column (Amicon glass column ca. 10 X 6 mm; i.e., ca. 0.5 ml), containing monoclonal antibody, immobilized on Nugel-polyhydroxy phase silica, 500 A, 200-400 mesh (Diagnostic Specialties, Metuchen, NJ, U.S.A.). The column has been automated so that the operator need only inject sample (0.25 ml) every 18 min (or one can use an automatic sample injector) and initiate the program cycle of the microprocessor. A hard-copy result from an integrator is available in less than 20 min. Routine analyses were performed at a flow-rate of 4 ml/min in the concentration range 0.02-0.3 mg/ml. Reproducibility of the assay was checked by assaying the same crude extract seven times in succession. Standard deviation was 3.96% and correlation coefficient was 0.9996. The advantages of this technique include rapid analysis time and relative simplicity, compared to the enzyme immunoassay.
