Which dosage form is a suspension of a drug in a water base for external use, with calamine lotion as an example?

Which dosage form is a suspension of a drug in a water base for external use, with calamine lotion as an example?

• A. Ointments
• B. Creams
• C. Gels
• D. Lotion

Answer: (D)

Lotions are topical preparations where solid drug particles are suspended in a mostly aqueous, water-based vehicle. This makes the product fluid, easy to spread, and non-greasy, ideal for external skin use. Calamine lotion fits this description well: it’s a suspension of calamine particles dispersed in an aqueous base, typically shaken before use to re-disperse settled solids, and applied to the skin for soothing effects. Ointments are oil-based and occlusive, which creates a greasy feel and isn’t water-based. Creams are emulsions, either oil-in-water or water-in-oil, not simple suspensions in a water base. Gels are semi-solid networks in which a liquid is immobilized within a gel structure, not merely a suspension in a water base.

Lotions are topical preparations where solid drug particles are suspended in a mostly aqueous, water-based vehicle. This makes the product fluid, easy to spread, and non-greasy, ideal for external skin use. Calamine lotion fits this description well: it’s a suspension of calamine particles dispersed in an aqueous base, typically shaken before use to re-disperse settled solids, and applied to the skin for soothing effects.

Ointments are oil-based and occlusive, which creates a greasy feel and isn’t water-based. Creams are emulsions, either oil-in-water or water-in-oil, not simple suspensions in a water base. Gels are semi-solid networks in which a liquid is immobilized within a gel structure, not merely a suspension in a water base.