Recent study looks at a type of polymeric micelle as a topical delivery mechanism for rapamycin.
My limited understanding of polymeric micelles is that they can be used as containers for drug delivery, and must be specially made for that purpose. So one could not get comparable results by mixing rapamycin with a commercial micellar hydrogel.
Dissolve in DMSO, you will get much better transport through the skin.
Transcutol is probably best for disolving rapamycin powder in (and then I added it to a standard skin cream like cetaphil)… I’ve heard that DMSO can stink.
See links here: Rapamycin for Hair and Skin
Also see: DIY Rapamycin skin cream
You can buy odor less DMSO.