the purpose of a cream is just slower absorption so the hair gets it longer. As an example, proxiphen cream once a day is stronger than proxiphen liquid twice a day. Same with spironolactone. I think it may be true of folligen too. The only reason people use liquids is if they have diffuse hair. But if you can get a cream on your scalp, it is better.
A cream only needs to evaporate slowly to be effective. It does not have to be thick. So if you can make one that does that and is not thick, you can have the best of both worlds and apply it to diffuse hair. I think glycerol may do that. I'd like to use fatty acids, but their low pH can destablize the CP's. I should ask my professor. He is very cocky and might tell me if he knows. If he does not know what non-toxic soluble chemical has a high boiling point and a low viscosity, he will just say he is too busy to think about that.