Improved robustness by concurrent rapid and non-destructive terahertz sensing of pharmaceutical tablet thickness and porosity.

Conventional porosity measurements of pharmaceutical tablets using terahertz time-domain spectroscopy (THz-TDS) in transmission geometry require supplementary thickness measurements-typically using an optical laser gauge-to enable accurate porosity determination. However, discrepancies in beam profiles between the laser and THz systems, as well as the need for precise mechanical positioning of the tablet for the two measurements, introduce potential systematic errors and complicate the measurement setup. This study presents a robust and rapid alternative: a transflection-based THz-TDS method that simultaneously determines both tablet thickness and porosity from a single terahertz waveform. By utilising a state-of-the-art, high-power THz-TDS system, we obtained sufficiently strong reflection features to extract both parameters without additional instrumentation. This approach overcomes the limitations of conventional transmission setups, offering a non-destructive, calibration-free solution for in-line porosity monitoring in pharmaceutical tablet manufacturing.

• Publication year

  2025

• Venue

  International journal of pharmaceutics

• Publication date

  2025-06-01

• Fields of study

  Medicine, Materials Science, Engineering

• Identifiers
  DOI 10.1016/j.ijpharm.2025.125773PMID 40490115
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

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