Which statement about filtration in elixir preparation is correct?

• A. Filtration is never required.
• B. Filtration is done after distillation.
• C. Filtration is required after standing to remove solids.
• D. Filtration is performed before standing.

Answer: (C)

In elixir preparation, you need a clear, uniform liquid, so you remove solid particles. After standing, insoluble solids settle to the bottom by gravity, separating from the liquid. Filtration then removes those settled solids (and any remaining fine particles) from the liquid, giving a clear filtrate suitable for dosing. Filtration before standing wouldn’t remove the solids that are still suspended, and filtration after distillation isn’t a general requirement for elixirs. Therefore, filtration is performed after standing to remove solids.