Work

Terahertz imaging of titanium dioxide-free film coating hydration and tablet core interactions

Year: 2026

Type: article

Abstract: Titanium dioxide (TiO 2 ) is often used as a white base pigment in film coatings, but recent EU restrictions on its use in food have prompted pharmaceutical manufacturers to seek alternatives. Terahertz pulsed imaging (TPI) was used to examine the hydration of TiO 2 -free immediate release formulations, either without an opacifier or using calcium carbonate (CaCO 3 ). The coatings, made from polyvinyl alcohol (PVA) or hydroxypropyl methylcellulose (HPMC), were approximately 100 µm thick. TPI results indicated that the type of film coating influenced hydration and scattering effects. However, there was no evidence that TiO 2 -free coatings compromised tablet disintegration. Although the HPMC coating with CaCO 3 gelled upon hydration, the tablets fully hydrated within the required time. These findings offer insights into the mechanistic impacts of alternative coatings in the industry.

Source: International Journal of Pharmaceutics

DOI: 10.1016/j.ijpharm.2026.126596

Authors: Mingrui Ma, Marwa Nassar, Jason Teckoe, J. Axel Zeitler

Institution: University of Cambridge

Language: English

Topic: Terahertz technology and applications

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,650