Lipophilicity Determination of Energy-Enhancing, Nootropic Supplements

Abstract

Nutritional supplements comprised a $123 billion industry globally in 2019 with energy and cognitive enhancement products constituting a quarter of that amount. However, these products are not regulated by the Food and Drug Administration (FDA) and manufacturers typically make bold, unsubstantiated claims of product efficacy. Unbiased, neutral-party evaluation is vital for public health safety. The goal of this study was to model the absorption of three energy-enhancing, nootropics (caffeine (1), theacrine (2), and methylliberine (3)) through the use of an octanol/water mixed solvent system and UV-Vis spectrophotometry to determine their lipophilicity. The measure of a molecule’s lipophilicity is a valuable pharmacological and toxicological property which is used to determine how well a molecule is absorbed through cellular membranes from extracellular fluid into the cell. Standard curves of known concentrations were created using serial dilution to enable analysis of the unknown concentration after partitioning. The resulting values were replicated by duplicate trials for validation of reproducibility.