Solubility and stability of some pharmaceuticals in natural deep eutectic solvents-based formulations

What happens when you mix everyday natural compounds like sugars and organic acids into a revolutionary liquid? You get a powerful new way to deliver stubborn medicines that refuse to dissolve in water.

Many vital medicines struggle with a fundamental flaw: they are poorly soluble in water. Yet, clinical routes like tube feeding and parenteral administration strictly demand liquid formulations. Enter Natural Deep Eutectic Solvents, or NADES. Crafted by mixing simple natural building blocks such as sugars, amino acids, organic acids, and poly-alcohols in precise molar ratios, these emerging mixtures are transforming pharmaceutical science.

Researchers tested a series of water-containing NADES to see how effectively they could stably dissolve challenging drugs at a baseline concentration of 5 mg/mL. The results were remarkably selective. Choline-based, acid-neutral, and sugar-based NADES successfully dissolved chloral hydrate, ranitidine hydrochloride, and methylphenidate up to an astonishing 250 mg/mL. Meanwhile, a specific lactic-acid and propylene-glycol mixture conquered spironolactone and trimethoprim at concentrations reaching 50 and 100 mg/mL respectively.

These findings spotlight NADES as exceptionally promising vehicles for liquid drug development. However, before these formulations reach clinics, future studies must rigorously evaluate their chemical stability and drug bioavailability.

Key Points

• NADES consist of mixed natural products like sugars and acids
• Selectively dissolved poorly water-soluble drugs up to 250 mg/mL
• Chemical stability and bioavailability require further studies