To evaluate this idea, we prepared twenty different IP+-linked MPs of various sizes and compositions and measured their rates of membrane transit using PAMPA (parallel artificial membrane permeability assay). Propranolol, a highly permeable low molecular weight (259 Da) drug and the much less permeable charged small molecule Ranitidine were employed as controls. In this assay compounds displaying a -log Pe below 6.0 are considered to be highly permeable, while those with a -log Pe between 6.0-7.0 are considered to be moderately permeable.