Hello, Welcome to healthcare magic. Your friend may need a course of oral antibiotics like cephalexin to dry up the wound. Pain and slow healing could indicate an infection which should be promptly treated with antibiotics. You could also apply an antibiotic cream containing 2 % mupirocin or 1 % fusidic acid twice a day. Antibiotic powder will not help much in such cases. Infact, it could stick to the wound and delay the healing process further. Hope this helps you. Take care.