Final answer:
To achieve maximum absorption of a topical medication, an ointment is the most effective vehicle due to its occlusivity.
Step-by-step explanation:
If you prescribe a prescription for a topical medication and want it to have maximum absorption, the most effective vehicle is an ointment. Ointments are semi-solid dosage forms used for topical application, offering the greatest occlusivity, which helps to increase drug absorption by trapping the medication on the skin and preventing moisture loss. Lotions, being low-viscosity and typically oil-in-water emulsions, are less occlusive and therefore allow for less absorption. Creams provide a balance and can be either oil-in-water or water-in-oil, with the latter being slightly more occlusive and thus potentially offering slightly better absorption than oil-in-water creams. However, ointments remain superior when the goal is to maximize drug absorption.