Solubility Chart - A work in (slow) progress.
Color key:

Tried it myself
From MSDS and Internet - have not tried it yet
Info from customers or forum posts - have not tried it yet

Updated: November 6, 2009

Product water Arlasolve DMI (Dimethyl isosorbide) glycerin oil Non-denatured
Ethanol
surfactant propylene glycol polysorbate 80 cream/lotion silicone gel
Allantoin Yes, 0.5% at 25 C No No No No No No No
Alpha Lipoic Acid
(RS-ALA)
No Yes Yes Yes dissolves well in oily cream
Ammonium Glycyrrhizae (Liquorice extract - white) Yes Yes Yes

L-Ascorbic Acid
(Vitamin C)

Yes Yes Yes No Yes, high water content Disperses well
Ascorbyl Tetraisopalmitate / Tetrahexyldecyl Ascorbate No No Yes Yes Yes Yes Yes Yes

Beta 1-3 Glucan (YEAST)

Yes, stir well to dissolve lumps. Yes Yes No best to mix with water first

Beta 1-3, 1-4 Glucan (OAT)

Yes, mix well in warm water. Use double boiler or microwave, do not boil solution. No No No No No best to mix with water first No

Beta Hydroxy Acid
(Salicylic acid)

No

"I am making my 2% SA serum with aloe vera. I heat the aloe vera, then add the SA and stir it, I let it sit for couple of hours while stirring as many times as I remember, then I buffer it with baking soda to bring the PH to the desired level. "
No Yes Yes Dissolves well in commercial facial cleansers

Boswellia serrata

No Yes Yes Yes disperses grainy
L-Carnitine Yes Yes Yes, can be a bit grainy if not enough water content.Microwave boost solves this
Coconut endosperm Yes

Centella Asiatica
(Gotu Kola)

No difficult, can form soft sticky lumps Yes

An alternative would be to add a small amount of your base cream with your ethanol content.
disperses grainy
CoQ10 No No Yes
DMAE Bitartrate Yes, may need warm water Yes Yes No
Dipotassium Glycyrrhizinate (Liquorice extract - white) Yes Yes Yes
Ellagic Acid disperses disperses
disperses
Ferulic Acid
(natural)
slight slight Yes disperses 
GABA Yes, warm water or microwave boost
Gamma oryzanol No Yes disperses well in oily cream
Glucosamine, N-acetyl-D Yes Yes
Ginkgo Biloba Yes best to mix with water first
Glycyrrhizinic acid (Liquorice extract - white) no yes

Grape Seed
Proanthicyanidins

slight Yes Yes Yes disperses grainy and sticky
Green Tea extract
(EGCG)
Yes No can be sticky

Horse Chestnut Extract

Horsetail powder No No No

Hyaluronic Acid
(NaH)

Yes Yes, but too much will make it feel like 'snot.'

Idebenone


Yes Yes dissolves well in oily cream (VERY strong color)
Jiaogulan (Gynostemma) Yes

Kojic Acid Dipalmitate (KAD

No Yes Yes Yes
Magnesium ascorbyl
phosphate (MAP)
Yes, make a paste, stir well to dissolve lumps No

Niacinamide

Yes Yes Yes, can be a bit grainy if not enough water content. Microwave boost solves this
Pine Bark extract Yes
(99%)

Pomegranate extract

disperses slightly grainy

SAS suggest adding a few drops to make a paste.

add the Pomegranate extract at a temp of 40 C or 104 F and mix with a mixer."
disperses slightly grainy Yes

Quercetin

very slight in hot water Yes No Yes
Resveratrol slight Yes Yes Yes
2g per 10 ml,
mix well
Saw Palmetto

Silymarin

No "I've just tried dissolving it in glycerin and it dissolves 100%. Useful for people who want an oil free serum or cream." "I found that the milk thistle extract dissolved completely in oil. I dissolved 1/4 tsp of the Silymarin in 1 tsp of sesame oil. 95% dissolved almost immediately. After leaving it to sit for 5 minutes I found it had completely dissolved, leaving me with a mustard colored oil with No grainy residue. Simply added it to my night cream. I have had difficulty getting it to dissolve in either warm water or alcohol." Yes disperses

Soy Isoflavones

Yes Yes Yes
White Willow - bark extract 80% Yes

Wild Yam
diosgenin
Yes Yes


Disclaimer: I am not a scientist or cosmetic formulator. This information is based on:
MSDS, COA, internet searches , forum posts, customer feedback , and practical experience

Supplier of: skin actives, cosmetic ingredients, cosmeceuticals, active ingredients, and skin care ingredients,  for DIY skin care and cosmetics, and homemade skin care products. 

DISCLAIMER:Any statements about products sold by BulkActives have not been evaluated by the FDA.  Products sold by BulkActives are not intended to be used as nutritional supplements. Products sold by BulkActives are not intended to diagnose, treat, cure, or prevent any disease.