Work out ointment base quantity instantly with clear inputs, formula shown and shareable results.
Subtracts the active ingredient and any other components from the total mass to give the quantity of ointment base needed.
Base quantity
Active mass = total mass x strength; base = total mass - active mass - other ingredients
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
Adding the full base mass on top of the active would raise the total and dilute the intended strength.
It depends on the site and the drug: paraffin bases occlude, emulsifying bases wash off and cream bases suit weeping lesions.