[whitecoatblackhat]

You may still have some dissolved even if you see some precipitates. You know for sure that the solution is saturated. Maybe try removing 10ml of the remaining solution and evaporate to dryness to see if there is still some dissolved.

Thanks for the suggestion.

Yes, you're right. A small portion of the beta-sitosterol might be dissolved but it's too infinitesimal to make a difference.

I wanted to create at least a 0.5% - 1% solution and possibly 5% (but that's highly unlikely now).

[whitecoatblackhat]

You could also try mixture of oil and ethanol.

Thanks for the suggestion rolnor!

I tried, it didn't work.

I tried alcohol, base oil, essential oil, polysorbate 20, 40 and 80, used PEG-40 Hydro. Cast. oil and none of these worked even in the slightest.

The only thing that works is heating the ethanol until boiling and then dissolving the beta-sitosterol with an immersion blender.

I'm able to create a 1% beta-sitosterol solution this way but it's only temporary. After 30 mins I'm starting to see precipitate.

Thanks!

[whitecoatblackhat]

Because of the structural and solubility similarities of beta-sitosterol and vitamin D3, I would look into how VD3 is formulated for fortification of milk etc.
Note that for VD2 (not a typo) solutions are prepared commercially in propylene glycol or sesame oil.
Water-insoluble, anti-cancer drugs were/are dissolved in arachis oil for testing on rats.

If you were to get into the manufacturing phase, Note that elution of ortho-phenylphenol from silicone tubing by sulfonated cyclodextrin has been reported.

Regards,
MOTOBALL

Thanks MOTOBALL, really appreciate your response.

I wasn't aware of the D3 and beta-sitosterol similarities. I'll look into it.

On the other hand, because beta-sitosterol is structurally similar to cholesterol, I also found that sulfobutyl beta-cyclodextrin can possibly dissolve it.

So what I found coincides with your suggestion.

My manufacturer produces sulfobutyl beta-cyclodextrin, so I can try it.

The only unknowns are whether it's safe on the skin and whether it interferes with the transdermal absorption of beta-sitosterol.

Thanks!!

[whitecoatblackhat]

What about using something like limolene or related interesting smelling alkenes as a solvent? Citral is another. The class of chemicals is called terpenoids or isoprenoids. They are found in fruit, cosmetics, etc.

Thanks for the response. Much appreciated!

I assume you mean limonene, not limolene?

They are found in essential oils. Limonene especially in grapefruit EO (or other citrus EOs).

I did try essential oils to solubilize beta-sitosterol and it didn't work.

Also, limonene seems to be a PGE2 antagonist and I'm trying to avoid that in the context of hair growth.

Thanks!

[wildfyr]

Can you use surfactants to keep it in the ethanol?

You've got a tough customer on your hands! I've never personally found any small molecules that, in an emergency, didn't have some solubility in hot DMSO, but clearly that's out of the picture.

[rolnor]

Have you tried to dissolve it in varm vegetable oil? You can heat to 100°C or even more.

[whitecoatblackhat]

Can you use surfactants to keep it in the ethanol?

You've got a tough customer on your hands! I've never personally found any small molecules that, in an emergency, didn't have some solubility in hot DMSO, but clearly that's out of the picture.

Yeah! I agree. Thanks for the suggestion.

As I mentioned in one of my above posts, I did try using surfactants to create some sort of an ethanol beta-sitosterol emulsion.

I used all the polysorbates/tweens and also PEG-40 hydrogenated castor oil.

Nothing worked.

As for DMSO, yeah. It's probably the most insane permeation enhancer and solubilizer ever.

I've heard anecdotes of people pouring a cup of strawberry juice, then rubbing their finger in DMSO and sticking it in the cup, which made them "taste" the strawberry juice through their finger.

That's how much it allows stuff to pass through the SC.

It's totally unscientific and anecdotal but it's still interesting to hear stories like that.

[whitecoatblackhat]

Have you tried to dissolve it in varm vegetable oil? You can heat to 100°C or even more.

Thanks for the suggestion!

Yes, I tried dissolving it in both cold and hot jojoba oil, olive oil, safflower oil and sunflower oil.

Nothing worked.

Beta-sitosterol is one of the toughest organic compounds, I've ever worked with.

Even if I did get it to dissolve somehow. The entire solution must be optimised for beta-sitosterol.

I won't be able to put other compounds in it. Which makes me more and more reluctant to continue pursuing this thing.

I'm looking into other things now, such as ketoconazole (in the context of hair loss prevention/hair growth).

Thanks!

[jeffmoonchop]

One method of trying to improve solubility is co-crystallization. Maybe you could search the literature for your compound and see if there are any (safe) coformers it likes. There are methods of cocrystalization that can be done without solubilization such as liquid assisted grinding. Add the coformers at the specific molar ratio, add a drop or two of solvent and grind them together. Or you can slurry them by stirring the coformers over night in solvent. The resulting cocrystal may be more soluble than the single compound and dissolve more readily in the solvents you've already tried.

[whitecoatblackhat]

One method of trying to improve solubility is co-crystallization. Maybe you could search the literature for your compound and see if there are any (safe) coformers it likes. There are methods of cocrystalization that can be done without solubilization such as liquid assisted grinding. Add the coformers at the specific molar ratio, add a drop or two of solvent and grind them together. Or you can slurry them by stirring the coformers over night in solvent. The resulting cocrystal may be more soluble than the single compound and dissolve more readily in the solvents you've already tried.

That's brilliant. Thanks a lot, I'll definitely look into co-crystalization.

[play150]

Hello,
I just wanted to chime in about my struggles with beta-sitosterol (practical grade, mixed with similar compounds like campesterol and stigmasterol) and also see if anyone found a solution.

I'm able to get cholesterol dissolved in an aqueous solution at 7.35 mg/ml by adding the powder to water that contains methylated beta cyclodextrin and microwaving lightly. I have the cholesterol and MBCD at a 1:6 molar ratio. However, this totally didn't work for beta sitosterol and I'm stumped! I even tried a 1:8 molar ratio and a lower final conc. of 4 mg/ml. I'm surprised as their chemical structures seem pretty similar.

Update: I just tried pure ethanol and I might have been able to get 4 mg/ml (it dissolved pretty slowly/gradually but seemed to be dissolved after ~2h)