Which base is typically non-water-absorbent but can hold small amounts of alcohol-based solutions?

Which base is typically non-water-absorbent but can hold small amounts of alcohol-based solutions?

• A. Water-removable base
• B. Hydrophilic ointment
• C. Oleaginous/Hydrocarbon base
• D. Aquaphor

Answer: (C)

The key idea is how bases behave with water and solvents. Oleaginous or hydrocarbon bases are non-water-absorbent and stay lipophilic on the skin; they don’t take up water. Because alcohol is miscible with oil, these bases can hold small amounts of alcohol-based solutions without introducing water into the system. That combination—not absorbing water, yet modestly incorporating alcohol solutions—defines an oil-based, hydrocarbon base. Hydrophilic or water-removable bases, by contrast, are designed to absorb water, and thus don’t fit the description. Aquaphor is an example of a petrolatum-based (oleaginous) base, reinforcing this concept.

The key idea is how bases behave with water and solvents. Oleaginous or hydrocarbon bases are non-water-absorbent and stay lipophilic on the skin; they don’t take up water. Because alcohol is miscible with oil, these bases can hold small amounts of alcohol-based solutions without introducing water into the system. That combination—not absorbing water, yet modestly incorporating alcohol solutions—defines an oil-based, hydrocarbon base. Hydrophilic or water-removable bases, by contrast, are designed to absorb water, and thus don’t fit the description. Aquaphor is an example of a petrolatum-based (oleaginous) base, reinforcing this concept.