In this post, Humectants: A closer look at panthenol, Bridget asks: I have a question in relation to the base panthenol is in. I know it is a water soluble vitamin therefore needs water to be dissolved but is it possible to use powdered panthenol in a 100% oily base and it be effective on the skin" I am wanting to create a healing balm without going down the attack of an emulsion and the risk of bacterial growth and cracking etc. I know ointment 100% bases are used all the time for salicylic acid and sulphur so why not panthenol" 

It's all about solubility. Salicylic acid can be solubilized in castor oil and olive oil (reference, reference, reference). Sulphur, which we can use as MSM, for instance, is oil soluble. Panthenol is strictly a water soluble ingredient.
You could add the powdered panthenol to an oil based product, but it isn't going to dissolve, so you'll end up with little shards of powder in the product that will be annoying to the skin. This is the case with other water soluble ingredients, like allantoin or our powdered extracts. They won't be available to our skin if you lock them away in an oil soluble product. You could put them in something that contains an emulsifier that will have water added to it, like an emulsified sugar scrub or a lotion bar with an emulsifier you could use in the shower, but they need water to work. Maybe you could make a nice water based spray that you put on your skin before using the balm or bar and see if ...