Isotropy

In physics and geometry, isotropy (from Ancient Greek ἴσος (ísos) 'equal' and τρόπος (trópos) 'turn, way') is uniformity in all orientations.

Anisotropy is also used to describe situations where properties vary systematically, dependent on direction.

Simple chemical reaction and removal of a substrate by an acid, a solvent or a reactive gas is often very close to isotropic.

Conversely, "anisotropic" means that the attack rate of the substrate is higher in a certain direction.

While it is well established that the skin provides an ideal site for the administration of local and systemic drugs, it presents a formidable barrier to the permeation of most substances.