Question

Which diluent is incompatible with primary amines?

• A. Lactose
• B. Mannitol
• C. Microcrystalline cellulose
• D. Dextrose

Hint:

When formulating drugs with primary amines, avoid using reducing sugars like lactose as diluents to prevent instability caused by Maillard reactions.

Answer 1

The Correct Option is A

Lactose is a reducing sugar commonly used as a diluent in pharmaceutical formulations. It contains a free aldehyde group capable of reacting with primary amines through the Maillard reaction, leading to the formation of brown-colored products and potentially affecting the stability and efficacy of the drug. This incompatibility is particularly significant when the active pharmaceutical ingredient contains primary amine groups. Other diluents such as mannitol, microcrystalline cellulose, and dextrose do not have the same reducing properties or reactivity with primary amines, making them generally compatible with such drugs. Therefore, lactose is considered incompatible with primary amines due to its reducing nature and potential to cause chemical interaction.