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

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.

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.