Distribution of ear drops in normal ears

Ear drops are prescribed widely with little thought for the distribution inside the ear canal. This study compares the distribution of water and oil based drops. The results indicate that, under the test conditions, the penetration of ear drops is extremely variable. Water provided the greatest overall coverage, while the most viscous drops fared worst. It is suggested that in diseased ears even poorer penetration may result, which may explain the lack of response in some circumstances.