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Diffusion and swelling measurements in pharmaceutical powder compacts using terahertz pulsed imaging
Samy Yassin1, Ke Su, Hungyen Lin
1Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge, CB2 3RA, UK.
Journal of Pharmaceutical Sciences
|February 4, 2015
Summary
Terahertz-pulsed imaging (TPI) non-invasively measures tablet swelling and water penetration. This technique offers new insights for developing pharmaceutical drug delivery systems and immediate-release formulations.
Area of Science:
- Pharmaceutical Sciences
- Materials Science
- Drug Delivery
Background:
- Tablet swelling and solvent penetration significantly impact drug dissolution.
- Understanding these processes is crucial for optimizing pharmaceutical formulations.
Purpose of the Study:
- Introduce terahertz-pulsed imaging (TPI) as a novel technique to quantify one-dimensional swelling and solvent ingress in pharmaceutical compacts.
- Evaluate TPI's applicability on common tableting excipients: hydroxypropyl methylcellulose (HPMC), Eudragit RSPO, and lactose.
Main Methods:
- Utilized terahertz-pulsed imaging (TPI) in reflection mode to monitor dimensional changes and solvent penetration.
- Employed X-ray microtomography and helium pycnometry to assess tablet porosity.
- Investigated water ingress into HPMC tablets over 24 hours.
Main Results:
- HPMC exhibited initial shrinkage followed by expansion (up to 20% in 24h).
- Lactose expanded significantly (up to 47% in 13 min), while Eudragit showed no dimensional change.
- Observed anomalous diffusion of water into HPMC tablets.
- Correlated TPI findings with porosity measurements.
Conclusions:
- TPI is a valuable tool for characterizing swelling and solvent ingress in pharmaceutical tablets.
- The findings support TPI's application in developing advanced drug delivery systems and immediate-release formulations.
- TPI provides a new avenue for quality testing of pharmaceutical products.
