Which statement about zinc oxide content in ointment versus paste is true?

• A. Ointment: 18.5–21.5%; Paste: 24–26%
• B. Ointment: 24–26%; Paste: 18.5–21.5%
• C. Ointment: 18–21%; Paste: 20–24%
• D. Ointment: 20–22%; Paste: 22–24%

Answer: (A)

The idea is that pastes have a higher solids content than ointments, giving a thicker, more protective barrier on the skin. Zinc oxide is a solid particulate used to boost that protective effect, so formulations classified as pastes typically contain more zinc oxide than ointments. Standard references show zinc oxide around 18.5–21.5% in ointments and about 24–26% in pastes, which matches option describing ointment ~18.5–21.5% and paste ~24–26%. The other ranges would imply the paste has about the same or less zinc oxide than the ointment or give inconsistent consistency, which doesn’t align with how pastes are formulated.