W/O emulsions, absorption bases, are also known as which product?

• A. Eucerin
• B. Aquaphor
• C. White petrolatum
• D. Hydrophilic ointment

Answer: (A)

Absorption bases are ointment bases that can absorb water to form a water-in-oil emulsion, creating a W/O system. Eucerin is a classic example of this type of base—that petrolatum-based product is formulated to take up water and develop a stable W/O emulsion, which is exactly what an absorption base does. White petrolatum, by contrast, is an anhydrous occlusive base and doesn’t form an emulsion on its own; hydrophilic ointment is a water-washable, typically O/W-type base; Aquaphor is petrolatum-based but not the standard representation of an absorption-base emulsion. So the product that fits the description best is Eucerin.