Chemistry: Develop ionic liquid drugs

Abstract

A new realm of potential drugs is hiding in plain sight. Pharmaceutical research, manufacture and regulation focuses on solid active ingredients, delivered as powders or tablets. Liquid forms are neglected and viewed as an intermediate step, rather than an endpoint.Yet many promising solid drug candidates are too insoluble for the body to absorb. Of Develop ionic liquid drugsUpdate regulation to spur research into drugs that the body absorbs more easily and that could reach market more quickly, urge Julia L. Shamshina and colleagues. . Ionic liquids can also be configured to deliver two or more active ingredients at once.For example, combining active ions from the pain reliever procaine and the non-steroidal anti-inflammatory drug (NSAID) salicylic acid generates a liquid salt, procainium salicylate. It could deliver the medical benefits of both compounds more efficiently and cheaply while opening up new treatment options.With the drug-discovery pipeline clogged, it is time to try alternatives. We call on chemists and the pharmaceutical industry to develop liquid salt forms of drugs. Chemists will need to learn more about the spectrum of interactions in ionic liquids, how to engineer ionic bonds, and how the choice of ions changes the chemical, physical and biological properties of ionic compounds. Regulations must be updated to consider active ingredients in liquid as well as solid states. OLD HABITSWhy are ionic liquids being ignored? First, most academic and industrial chemists lack understanding and experience of working with them. Chemistry courses and textbooks teach that new molecules are made by manipulating covalent bonds (where electrons are shared between atoms) rather than ionic ones.Second, pharmaceutical companies are conservative. Ionic liquids are unfamiliar, unregulated and felt to be too risky to develop commercially.And there is a perception problem. Over the past 20 years many researchers (including us) have demonstrated the value of ionic liquids as solvents, electrolytes and compressor fluids that are reusable, non-volatile and safe. Yet many researchers and journalists still associate the term with the first such chemicals widely studied: for example, dialkylimidazolium, quaternary ammonium and phosphonium salts, which were explored in the 1990s as potential 'green' solvents and electrolytes. With each new study, the class as a whole became pigeonholed -as expensive, cheap, green, toxic, biodegradable, nonbiodegradable, non-flammable, flammable, volatile or non-volatile. In reality, ionic liquids have an infinite range of characteristics.The effect of an ionic liquid on a living organism (such as toxicity) should be exploited rather than being seen as a problem, especially given that liquid salts can be more soluble in the body than are solids. The rate at which a drug is taken up depends on many factors, including its solubility, permeability, dissolution rate and the metabolic pathways involved.Ionic liquid pharmaceuticals face similar problems to nanotechnology.

How imidazolium‐based ionic liquids solubilize the poorly soluble ibuprofen? A theoretical study

“…In order to solve the problem, some scientists have suggested that it is of great value to replace the widely used toxic organic solvents by safely, biodegradable, and environmentally friendly neoteric solvents for the development of sustainable pharmaceutical processes . Ionic liquids (ILs) as neoteric solvents, with the advanced characteristics of non‐volatility, non‐flammability, and high recyclability, have been proposed as green solvents for the extraction, separation, crystallization, and purification of drugs . Particularly, existing experimental data showed that most of imidazolium‐based ILs were considered to be a biodegradable IL and to exhibit quite a low toxicity on human body, which made them even as the component of the active pharmaceutical ingredients (APIs) .…”

The Anticancer Potential of Ionic Liquids

“…For the aforementioned reasons, special attention has been given to ILs over the last few years . Studies of the effects of ILs as antitumor agents have brought new perspectives to the use of this compound class.…”

Investigation of pharmaceutically active ionic liquids as electrolyte for the electrosynthesis of polypyrrole and active component in controlled drug delivery

“…[22,24] Since 2007, Room Temperature Ionic Liquids (RTILs) containing active pharmaceutical ingredients have aroused strong interests as they limit drugs polymorphism and improve their solubility. [29][30][31][32][33] API-ILs have also been used as solvent for poorly soluble drugs [34][35][36][37][38] and as drug delivery systems in the form of microemulsions [39] and micelles. [40] Drug delivery systems have also been obtained by immobilization of API-ILs into silica either by sol-gel processing, [41] adsorption to silica [42] or into biocompatible poly(L-lactic acid).…”