Absorption Screening Using the PAMPA Approach

The parallel artificial membrane permeability assay (PAMPA), as a passive-permeability screen, is an excellent alternative to cellular models for the earliest absorption, distribution, metabolism, and excretion (ADME) primary screening of research compounds. PAMPA’s popularity in the industry has risen rapidly. This chapter focuses on state-of-the-art PAMPA methods. Evidence will be cited demonstrating that as far as predicting passive permeability, PAMPA can outperform cellular models in speed, versatility, and especially cost, presenting a compelling and biologically relevant model of transport. The problem of low solubility of research compounds has been largely eliminated in the newest PAMPA variant, using a unique cosolvent method. This chapter also discusses how PAMPA has relevance in preformulation research. A detailed PAMPA protocol is presented, with step-by-step instructions for a popular version of the assay, using relatively inexpensive and readily obtainable components.