N-ethyl-2-pyrrolidone (NEP) is a colourless and highly polar liquid. It can be used as a highly effective selected solvent, catalyst and cationic surfactant in industry (e.g. coatings). NEP has been shown to display a spectrum of developmental toxic and teratogenic effects in rodents after oral administration. The oral LD50 of NEP in rats was reported to be 1.36 g/kg. The two postulated NEP metabolites 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N ethylsuccinimide (2-HESI) have recently been detected in urine samples from the general population.

Ethyl Ferulate is an ester type of Ferulic Acid and has powerful antioxidant, free radical scavenging and UV adsorption properties. Ethyl Ferulate can be incorporated into various cosmetic formulations including aqueous, ethanolic and emulsion-based creams, sun creams or moisturizers. Ethyl ferulate demonstrated the cytoprotective effects against oxidative damage in neuronal cells. Ethyl ferulate has also been widely studied and some recent findings include its anticholinesterase activity; inhibition of nuclear factor-kappa B (NF-κB) activity in LPS-stimulated RAW 264.7 macrophages; inhibition of inducible nitric oxide synthase (iNOS) induction in UV-induced oxidative stress in melanocytes; induction of heme oxygenase (HO-1) activity in rat astrocytes and neurons, which is a putative pathway against oxidative stress that underline neurodegenerative diseases; and cytoprotective effect against reactive oxygen species (ROS)-induced damage through the stimulation of dermal fibroblasts stress response.