The topical product shown below contains how many mg of the active ingredient Crisaborole in each gram of the product? [Image of Eucrisa (crisaborole) ointment 2%]

Step 1. Define the 2% concentration. 2% w/w means 2 g of drug in 100 g of ointment. Step 2. Convert to mg per 100 g. 2 g x 1,000 mg/g = 2,000 mg per 100 g. Step 3. Calculate mg per 1 gram. 2,000 mg / 100 g = 20 mg per 1 gram.