He is known as an excellent researcher.

He learned how to make a potion from an old book.

He went to the hospital because of a drug rash.

My eyes were hurting, so I used eye drops.

This gunpowder has been used since ancient times.

There is an old pharmacy in my town.

He is suspected of being involved in the illegal trade of narcotics.

He put a ring on his ring finger.

This medicinal plant has been used since ancient times to maintain health.

You cannot buy this drug without a doctor's prescription.