Presentation Floxapen 250: Each capsule contains Flucloxacillin 250 mg (as Flucloxacillin Sodium BP). Floxapen 500: Each capsule contains Flucloxacillin 500 mg (as Flucloxacillin Sodium BP). Floxapen Powder for Suspension: Each 5 ml reconstituted suspension contains Flucloxacillin 125 mg (as Flucloxacillin Sodium BP).