What is the best masking medium to administer tb medicine for an 18 month old child?

That's a tough one: Some kids really resist meds and rather than disguising the taste, it is easier to reward taking the Med with a treat. Meds that are chilled usually have less after taste. Chocolate is a good cover for bitter taste and works for some. Very young children can sometimes be taught to swallow a pill, using a small piece of candy in a pureed food such as applesauce or fruit flavored yogurt.