  We present a mechanistic model of drug release from a multiple emulsion into
an external surrounding fluid. We consider a single multi-layer droplet where
the drug kinetics are described by a pure diffusive process through different
liquid shells. The multi-layer problem is described by a system of diffusion
equations coupled via interlayer conditions imposing continuity of drug
concentration and flux. Mass resistance is imposed at the outer boundary
through the application of a surfactant at the external surface of the droplet.
The two-dimensional problem is solved numerically by finite volume
discretization. Concentration profiles and drug release curves are presented
for three typical round-shaped (circle, ellipse and bullet) droplets and the
dependency of the solution on the mass transfer coefficient at the surface
analyzed. The main result shows a reduced release time for an increased
elongation of the droplets.

Soft Condensed Matter