Effect of Size and Shape of Tablets and Capsules on Ease of Grasping and Swallowing (1) : Comparison between Elderly and Students

Abstract

The size and the shape of tablets and capsules may influence the taking of medicines and compliance in elderly patients may be negatively affected by physical disabilities and/or swallowing difficulties. In order to develop medicines that are easy for patients to grasp and swallow, we conducted a sensory test regarding the size and shape of tablets and capsule size, in which our subjects were elderly people (average age : 71.9) and students (average age 22.3). Eighteen white imitation tablets of different shapes (circular, oval, rectangular) and varying from 5.0-13.0 mm in size, and six different imitation capsules were prepared for the test and the subjects' feelings about them were determined through interviews. The subjects took the tablets in the pre-assigned order and evaluated them according to 3 levels concerning ease of grasping and ease of swallowing. Based on the overall results for the elderly subjects and students, the easy-to-grasp, easy-to-swallow size was determined to be 7-8 mm in diameter for circular tablets, 9 mm in the longer axis for oval tablets, 9-10 mm in the longer axis for rectangular tablets, and the No. 3 size for capsules. Thus, among prescription drugs available in Japan, easy-to-grasp, easy to swallow circular tablets account for 35% of the total, 16% of the total for oval tablets, 9% of the total for rectangular tablets, and 32% of the total for capsules. Our findings suggest that more effort should be put into the design of medications regarding their size and shape in order to improve patient compliance.