Sensory testing assessment of dosage forms designed to resist overdose

Overdose incidence has increased among young individuals, particularly involving psychotropic and over-the-counter (OTC) drugs. However, there is limited information regarding how the physical form of medications-such as tablet size or thickness-affects the ability to take large doses. This study aims to determine which tablet characteristics (size, thickness, and volume) can discourage overdose by using sensory testing methods. The diameters and thicknesses of tablets commonly used in overdosing were measured. Additionally, dummy tablets were three-dimensionally (3D) printed, after which sensory tests were conducted to evaluate how many tablets could be comfortably consumed in large quantities, as well as the ease of consumption, rated on a 5-point scale. The respondents were students (average age: 21.3 ± 2.1 years, n = 253). Results indicate that OTC drugs typically have larger and thicker tablets compared with prescription drugs. Sensory tests of 3D-printed dummy tablets found that smaller tablets are easier to ingest in large numbers, whereas larger and thicker tablets are harder to consume in bulk. For tablets with the same diameter, a 5-mm thickness tends to make overdose more difficult compared with a 2-mm thickness. Importantly, tablets with a combined diameter and thickness of 13 mm or more and a volume of at least 190 mm³ are less likely to be overdosed. These findings can assist pharmacists in selecting appropriate dosage forms for patients at risk of overdose and provide pharmaceutical companies with guidance during product development.