Concept:
Tolu balsam is a balsamic resinous substance used in pharmaceutical preparations.
Step 1: Tolu balsam has pleasant aromatic odour.
Step 2: It is used as a flavouring agent in pharmaceutical formulations.
Step 3: It also has expectorant property and helps in respiratory preparations.
Step 4: It is not mainly used as antimalarial, antidiabetic, or cardiotonic agent.
\[
\boxed{\text{Expectorant and flavouring}}
\]