Cloudiness and Effectiveness of Gel with Resveratrol + Soy Extract

Subject: Cloudy Gel with Resveratrol + Soy Extract

Regarding the cloudy appearance of your gel formulation after refrigeration, this is a known characteristic, likely caused by the Soy Extract (specifically, the component genistein).

Genistein has very low solubility, especially at low temperatures. When the gel is refrigerated, the genistein may precipitate out, causing the cloudy appearance. This is more likely to happen with highly concentrated extracts.

Regarding the effectiveness:
While the genistein is less soluble when cold, it is expected to redissolve when applied to the skin, as skin temperature is higher. This should allow it to be absorbed.
If you are concerned, you can test this by applying the gel and checking if any powdery residue is left on the skin after the water evaporates (around 5 minutes). If no residue is left, it indicates the genistein has redissolved.

In summary, the cloudiness is a normal physical change due to the properties of Soy Extract at low temperatures. The product should still be effective as the genistein is expected to redissolve upon application. If the cloudy appearance is undesirable, formulating the product as a cream is a suggested alternative, as the opacity of the cream base would hide the precipitation.