  In a previous report [10] it was shown that emulsion stability simulations
are able to reproduce the lifetime of micrometer-size drops of hexadecane
pressed by buoyancy against a planar water-hexadecane interface. It was
confirmed that small drops (ri<10 {\mu}m) stabilized with {\beta}-casein behave
as nondeformable particles, moving with a combination of Stokes and Taylor
tensors as they approach the interface. Here, a similar methodology is used to
parametrize the potential of interaction of drops of soybean oil stabilized
with bovine serum albumin. The potential obtained is then employed to study the
lifetime of deformable drops in the range 10 \leq ri \leq 1000 {\mu}m. It is
established that the average lifetime of these drops can be adequately
replicated using the model of truncated spheres. However, the results depend
sensibly on the expressions of the initial distance of deformation and the
maximum film radius used in the calculations. The set of equations adequate for
large drops is not satisfactory for medium-size drops (10 \leq ri \leq 100
{\mu}m), and vice versa. In the case of large particles, the increase in the
interfacial area as a consequence of the deformation of the drops generates a
very large repulsive barrier which opposes coalescence. Nevertheless, the
buoyancy force prevails. As a consequence, it is the hydrodynamic tensor of the
drops which determine the characteristic behavior of the lifetime as a function
of the particle size. While the average values of the coalescence time of the
drops can be justified by the mechanism of film thinning, the scattering of the
experimental data of large drops cannot be rationalized using the methodology
previously described. A possible explanation of this phenomenon required
elaborate simulations which combine deformable drops, capillary waves,
repulsive interaction forces, and a time-dependent surfactant adsorption.
