Amoxicillin daily doses is 25 mg/kg/day and the patient weight is 43 lb, so the amount of drug needed would be: 25 mg/kg/day * (43lb * 0.453592kg/lb) = 487.5mg/day
The drug administered per 8hr, so the doses for every would be: 487.5mg/day * (1day/24hr) * (8hr/dose)= 162.5mg/dose.
The concentration of suspension is 250 mg/5 ml, so the ml of drug needed would be: 162.5mg/dose / (250mg/5ml)= 3.25ml/dose