Deep eutectic solvents (DESs) are a relatively new type of solvent that have attracted the attention of the scientific community due to their environmentally friendly properties and their versatility in many applications. Many possible DESs have been described and, thus, it is not easy to unequivocally characterize and generalize their properties. This is especially important in the case of the (eco)toxicity information that can be found for these mixtures. In this review, we collect data on the human and environmental toxicity of DESs, with the aim of gathering and exploring the behavioral patterns of DESs. The toxicity data found were analyzed attending to different factors: hydrogen bond donors or acceptors that form part of the eutectic mixture, pH, and the presence of organic acids in the DES molar ratio of the components, or interactions with natural compounds. In the case of ecotoxicity, results generally depend on the biomodel studied, along with other factors that have been also revised. Finally, we also carried out a revision of the biodegradation of DESs.

Therapeutic Deep Eutectic Systems (THEDESs) are a mixture of components, including an active pharmaceutical ingredient, that have recently emerged because of their interesting properties for drug therapies. In general, they have been recognized to increase the solubility and permeability of some drugs, and consequently, their bioavailability. Moreover, they have also been used for novel formulations of pharmaceuticals. Despite the potential benefits of THEDESs, concerns about their safety and toxicity remain. In this review, we summarize previous studies that have investigated the toxicity of THEDESs. These studies evaluate the toxicity of THEDESs using various methods, including cell cultures, animal models, and human trials. The results of previous findings suggest that THEDESs are generally well-tolerated and have low toxicity. However, further research is needed to fully understand the long-term effects of these systems on human health and to identify any potential adverse effects.

A systematic review was conducted on the migration of compounds from plastic containers in the food and pharmaceutical industries, using Web of Science databases and following PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The protocol has been registered with the OSF registry, with the DOI 10.17605/OSF.10/UQ3T2. This review included only review articles in English published within the last fifteen years. Four reviewers independently screened titles and abstracts, discussing inclusion criteria. In this comprehensive evaluation of the information present in an Excel spreadsheet, a substantial number of records were discarded because they were not representative of the topic under study. Following the review process, a total of twenty-eight key records were selected, primarily focusing on migration in the food and pharmaceutical sectors. Of these, twenty-four addressed only food, just two addressed only pharmaceutical sector, and two covered both fields, highlighting limited information on migration in pharmaceuticals, cosmetics, and related products. The analysis emphasized the types of compounds studied, the analytical methods employed, the migration tests conducted, and the toxicity assessments undertaken. The most frequently assessed compounds included phthalates, endocrine disruptors like bisphenol A, and non-intentionally added substances (NIAS). Analytical methods used typically involved pre-treatment steps, such as liquid–liquid or solid-phase extraction, followed by gas or liquid chromatography, depending on compound volatility.

Bioactive compounds (BCs) are naturally occurring molecules found in plants, fungi, and microorganisms that can provide health benefits beyond nutrition. However, in order to administer them, they must be extracted from these organisms. This study reviews the extraction of anti-inflammatory bioactive compounds using deep eutectic systems (DESs). It was found that DES extraction media can be categorized as either choline chloride-based or natural product-based (e.g., proline, betaine, and lactic acid). Results indicate that extraction yields depended on many factors such as extraction method and DES composition, with values ranging from 0.02 to 200 mg/g. For example, curcumin extraction using ChCl–propylene glycol (1:2), for example, reached 23.1 mg/g, whereas rutin extraction using ChCl–levulinic acid (1:2) achieved 200 mg/g. Regarding this, most of the eutectic mixtures used are choline chloride (ChCl)-based combined with sugars, polyalcohols, organic acids, or even water. Nonpolar DESs combining betaine, L-proline, amino acids, sugars, and organic acids have also been used for the extraction of BCs with anti-inflammatory potential. Although the use of DES offers significant advantages for extraction processes, certain limitations still need to be overcome. This review highlights the comparative advantages of DESs in terms of extraction efficiency and environmental sustainability, offering practical insights for selecting optimal systems to extract anti-inflammatory bioactive compounds.