Yesterday's question relates well to the one posted posed on Patreon by Omitade:  I have a very basic question, probably answered somewhere. I recently purchased Panthenol Liquid and what I realized is that I don't really understand how the recipe changes when you use liquid or dry ingredient of the same thing.  I make a lotion with 2% dl-panthenol and up to this point, I have used the dry ingredient. Now that I have the liquid, is it the same amount" In my brain that doesn't seem right but it could be.

Great question, and no, it hasn't been asked or answered!

This may get a little long, but I promise we'll get somewhere in the end, unlike most of the stories I tell...

Let's say you have a container of salt and a container of brine. The container of salt crystals contains 100% salt. The brine contains 20% salt. If a recipe calls for 20 grams salt, you could either add 20 grams of the salt crystals or 100 grams of brine to get 20 grams of salt. In this example, the liquid has less salt in it than the crystal form, so we'd have to alter our recipe to ensure we're getting the concentration we want for the salt.
Let's say we have a container of salt and a container of salt dissolved in water. Each contain 100% salt, one in crystal form and one in liquid form. (Just go along with this for a few moments to make this example work...) If we require 20 grams of salt in a product, we could add 20 grams of each and achieve the same result - 20 grams of salt in ...