These situations are all about thermodynamics. The interaction of the solute with the organic molecules must be more energetically favoured than with water molecules. The release of this energy during the interaction would result in a minimisation of the Gibbs free energy of the system. The more favourable interaction is, probably, due to the relatively reduced polarity of the ethanol compared to water.

So, do you think it is possible to dissolve curcumin in this mixture?

Hi

As curcumin is very soluble in ethanol (see : ftp://ftp.fao.org/es/esn/jecfa/cta/CTA_61_Curcumin.pdf) I would expect that you will find an ethanol water mixture in which the solubility is  acceptable for your needs but I cannot say what the minimum ethanol concentration will be. Why not try an experiment?

Alan

thank you Alan! 

I'm waiting for the curcumin which I ordered last month !

I have seen the curcumin dissolve in water with the addition of a few drops of triethylamine and it will turn the solution a deep red color. You could just practice on the spice powder while you wait for your order to arrive. Have fun!

Curcumin is soluble in organic solvents such as Dimethyl Sulfoxide (DMSO), Acetone and Ethanol but poorly soluble in water.

Solubility in ethanol (10 mg/ml), DMSO (25 mg/ml), acetic acid, 0.1M NaOH, 10mM Na2CO3, acetone, water (< 0.1 mg/ml), and chloroform.

Curcumin is organic in nature it dissolves in organic solvents, if u want to dissolve it in water you have to prepare its sodium or potassium salt, then it can be easily soluble in water. Prepare basic solution of sodium or potassium hydroxide by adding a small amount of sodium or potassium hydroxide to distilled water, then add curcumin to this solution or just make the water solution basic of pH between 8-8.5 and add curcumin to it, it will dissolve in it or in Ethanol/Water mixture 

Prepare its salt such as sodium or potassium

There is a great lay site that I recall from several years ago of some Curcumin users trying to sort out how to dissolve their curcumin and they used some nice ingenuity and discussion along the way. I will include here as it was quite delightful and involved just your question. From "Margaret's Corner." It did not discuss Hot Melt's or great detail of how admixture of polymers or nano particles can benefit your potential struggle--lots of that at multiple data sites, as I am sure you have already seen. As well known, and you mourn, due to its hydrophobic nature, curcumin is poorly soluble in neutral solvent (i.e. water). Curcumin’s solubility is improved slightly in basic conditions but then degrades.And, curcumin is readily soluble in organic solvents such as ethanol, methanol, isopropanol, acetone and dimethylsulfoxide (DMSO), has moderate solubility in hexane, cyclohexane, tetrahydrofuran and dioxane. So: curcumin is insoluble in aqueous solution, extremely unstable in alkaline condition, and, darn--easily degraded and metabolized by human body.But at least, a large surge of scientific data reporting the conversion of water-insoluble curcumin into nano-sized particles, with greatly improved curcumin’s solubility and consequently its bioavailability in vivo 

Not being water soluble has kept curcumin from being really useful as a medical agent. 

SO WHAT ELSE DOES DISSOLVE IT?? " Several terpene glycosides, such as mogroside V, paenoiflorin, geniposide, rubusoside (Ru), stevioside (Ste), rebaudioside (RebA), and steviol monoside, have shown the ability to enhance the solubility of a number of pharmaceutically and medically important compounds with poor solubility in water. Ru can enhance the solubility of curcumin from 0.6 mg/ml to 2.3 mg/ml with 1–10% Ru (w/v) solution in water 

Curcuminoids powder prepared with ethanol directly from turmeric powder showed low or no solubility in water. In the study I link to below, At the optimum extraction condition for soluble curcuminoids, the relative concentrations of curcumin, DMC, and BDMC in total water soluble curcuminoids were 32.4%, 27.0%, and 30.5%, respectively, with Ste, 31.3%, 27.1%, and 31.4%, respectively, with RebA, and 30.3%, 26.7%, and 32.7%, respectively

The authors I link to--which I am sure everyone who is researching this is read so forgive me!!--report:

Until now, most studies have used commercial available curcuminoids extracted by organic solvents. They have enhanced its solubility by using nanoparticles, liposomes, micelles, phospholipid complexes (Ji, Huang, & Zhu, 2012), or rubusoside (Zhang et al., 2011). The processes for preparing water soluble curcuminoids are complicated and expensive. For the first time, we report the simple preparation of water soluble curcuminoids from turmeric powder by using Ste, RebA, or SG.

So--curious--why looking at Ethanol and water? And my apologies for mentioning what all of you in this field have already seen from Nguyen. I left out all the other refernces before people here staged a riot. No insult intended. Just an interesting topic and have read a lot of the studies too

Here, by the way, Margaret's Corner from 2007: 

"I have researched the best way of taking curcumin and it’s complicated. As noted above curcumin is essentially insoluble in water especially at low and moderate Ph. It will go into fats but then the fats are insoluble in water too so the curcumin will stay partitioned into the fat and not absorbed. Fat is solubilized by bile which is alkaline and fat dissolved curcumin is also more soluble at alkaline Ph but here curcumin is destroyed quickly by hydrolysis so using fat as a carrier is a dead end IMO.

For this reason I think it’s better to imbibe mixtures of ethanol and water as the carrier solvent. Limiting solubility of curcumin in pure water is .006 grams per liter. For pure ethanol it is 10 grams per liter. For mixtures it is a sliding scale between these two limits. Wine at 13% ethanol should carry 1.3 grams of solvated curcumin per liter bottle of wine. A therapeutic dose of curcumin is about 0.2 grams for a 100 kg adult at a minimum so one glass of wine should deliver one therapeutic dose. You can drink the curcumin as a slurry in Orange juice and chase it with the wine letting it mix in your stomach for better wine taste and excess curcumin slurried in the juice won’t hurt anything it just won’t dissolve beyond the solubility limit.

With this method you can achieve high sustained therapeutic dosings by drinking a glass of wine periodically throughout the day."

Best, marybeth Lambe MD FAAFP

http://www.sciencedirect.com/science/article/pii/S0308814616311244

Hi, i am also interesting in same question. I am palning to prepare CUR-Nanocrytsals assisted via sonication. most papers mentioned to dissolve in 60% ethanol. Can anyone please tell me exact amount of cur (mg)/ ml of 60% ethanol would be the best to use it. Thanks

 Hi, I just dissolved the curcumin which is in 500mg in a bottle with 3ml of 95% absolute ethanol. The solubility mentioned 1mg/ml in 95% absolute ethanol and I did further dilution to prepare as stock solution using the ethanol again. Am I doing it right?

Using basic solution you degrade curumin in al red and well water soluble compound. Using basic solution with curcumin is to avoide. 

DMSO is doing me some wonders of dissolving curcumin. I therefore do not hesitate to recommend its use.

Curcumin is completely soluble in acetone. Solubility in ethyl acetate and methanol if around 70-80%

Curcumin is insoluble in n-hexane

Does anybody know which is the solubility of curcumin in acetone?

Thanks!

Curcumin is not soluble in water, but soluble in ethanol. It is amazing to carry out some test, to understand the maximum dissolved curcumin in ethanol. I faced an issue when I have maximum dissolved curcumin in ethanol, the moment I add some water in (not much), some red sticky stuff appeared in the solution, likely solid curcumin, is it true?

Juan Bui that is totally true, I have observed the same... even if u are not adding water, if you stored the solution for long time under wet condition you may observe the this. That suggest to me that water have been absorbed from the ambient.

The best way for dissolving curcumin is 1mg curcumin /1ml of ethanol % 96.