Apart from cell-based experiments, there are several in vitro membrane-based methods. The most often used one is the parallel artificial membrane permeability assay (PAMPA) . The membrane on which PAMPA methods are based is artificially made and chosen depending on the membrane the assay mimics. To this date, many variants of PAMPA have been published. The examples include DS-PAMPA , which mimics gastrointestinal absorption, blood-brain barrier PAMPA , SkinPAMPA , or nasal-PAMPA . Another long-time-known experimental method of permeability measurement is BLM (Black Lipid membrane), first published by Mueller et al. . In this experimental setup, membranes are prepared in the form of very thin lipid films. This method is suitable as a model of more complex natural membranes. Unlike CACO-2 or MDCK, which employ a monolayer of complex living cells, PAMPA and BLM methods both use simpler membranes that are unable to effect active transport (influx as well as efflux), paracellular transport, metabolism, or ion-trapping in lysosomes. Experimental methods for the determination of membrane permeability have been supplemented by in-silico approaches, which can be divided into three main categories: molecular dynamics simulations, physics-based computational methods, and machine-learning statistical models.