What to do if i discovered boots ibuprofen/codeine 200/12.8mg which gives 25.6mg overall each dosage. is there any better?

You misunderstand : Ibuprofen/ Codeine 200/12.8 is not a fraction. It signifies a dose of 200 milligrams of ibuprofen together with 12.8 milligrams of codeine. A normal adult dose . If they were prescribed for you, take them as directed. If you found someone else's pills, get rid of them. Never take prescription pills belonging to someone else as they might do more harm than good.