Could someone please elaborate on why propylene glycol (PPG) is often added to topical formulations of minoxidil and finasteride?
I understand minoxidil doesn't fully dissolve in ethanol alone, but finasteride does.
I have been experimenting with topical formulations for finasteride, and so far, in terms of comfort, 90% "real" consumption ethanol and 10% pure water work well. By using pure ethanol, there is no nasty smell or irritation because of the methanol used in denatured ethanol, it's not greasy and it dries fast (I'm not entirely sure whether it dries/absorbs or evaporates though hahaha).
I understand minoxidil doesn't fully dissolve in ethanol alone, but finasteride does.
I have been experimenting with topical formulations for finasteride, and so far, in terms of comfort, 90% "real" consumption ethanol and 10% pure water work well. By using pure ethanol, there is no nasty smell or irritation because of the methanol used in denatured ethanol, it's not greasy and it dries fast (I'm not entirely sure whether it dries/absorbs or evaporates though hahaha).