Answered by Shaykh Faraz Rabbani
Question:  Does applying cream and powder on the body and face break one’s fast?  Can one apply topical medications such as Retin-A that are absorbed by the skin?
Answer:  No, applying cream and powder to the body does not break one’s fast. The fast is invalidated by things entering the body cavity itself. This is why even injections do not invalidate the fast.
 In the Hanafi school, such medication would not affect your fast in any ways. In fact, even injections do not break the fast.