Cloxacillin Powder is the best option to avail the benefits of cloxacillin if the patient is unable to consume a tablet. Great for treating various bacterial infections, this medication belongs to the family of penicillin antibiotics. Cloxacillin Power works by preventing the development of bacteria within the patientÃ¢ÂÂs body. However, many people get confused with bacterial and viral infections. It is taken by mouth on an empty stomach or can a couple of hours after meal, otherwise directed by the doctor.