Micropipette manipulation: A technique to evaluate the stability of water‐in‐oil emulsions containing proteins

The influence of size, structure and hydrophilicity of model surfactants on the adsorption of lysozyme to oil–water interface—Interfacial shear measurements

“…Earlier Freer et al have defined the crossover from where the monolayer is fully formed and evolvement of a multilayer starts as the crossover to a dominant elastic behavior in the system, or more precisely where a drastic increase in G is observed and G levels off [18]. Various surfactants have been used in order to hinder the adsorption of proteins to oil-water interfaces [5,14,19,20].…”

“…Differences linked to the type and composition of surfactants, and intuitively also concentration, have been illustrated [14]. Using interfacial sheer measurements, it is possible to describe in detail how various surfactants affect protein adsorption.…”

Kinetics of Insulin Adsorption at the Oil–Water Interface and Diffusion Properties of Adsorbed Layers Monitored Using Fluorescence Correlation Spectroscopy

“…Investigations on the effect of detergents should use a different means of fixing the interface, such as the micropipette technique (6). …”

“…To be able to optimize their function in drug delivery systems, information about the behavior at the interfaces created in drug delivery systems must therefore be obtained. A micropipette technique was recently used to study the surface formed at the interface between oil and a protein solution (6). In these experiments a condensed film was formed at the surface of the droplets.…”

Alginate microspheres prepared by internal gelation: Development and effect on insulin stability

“…When emulsions are prepared, the total interfacial area increases as the droplet size decreases but it was observed that the exposure to the oil-water interface combined with the mechanical stress of manufacture is not quite as harsh a treatment as simple shaking and exposure to the air-solution interface (Jorgensen et al, 2003). Furthermore, a better protection of the protein from exposure to interfaces may be obtained by addition of surfactants due either to a steric effect which blocks aggregation-prone hydrophobic sites on the protein surface (Bam et al, 1998) or to a competitive effect with the protein for space at the surface, thereby, preventing part of the protein from reaching the interface and the subsequent adsorption and structural perturbation (Jorgensen et al, 2004). This may explain the preservation of insulin stability during microspheres preparation, suggesting that emulsification/internal gelation is appropriate for the encapsulation of proteins.…”