Abstract-Review of Terahertz Pulsed Imaging for Pharmaceutical Film Coating Analysis

Décio Alves-Lima, Jun Song. Xiaoran Li, Alessia Portieri, Yaochun Shen, J. Axel Zeitler, Hungyen Lin

https://www.mdpi.com/1424-8220/20/5/1441

Terahertz pulsed imaging (TPI) was introduced approximately fifteen years ago and has attracted a lot of interest in the pharmaceutical industry as a fast, non-destructive modality for quantifying film coatings on pharmaceutical dosage forms. In this topical review, we look back at the use of TPI for analysing pharmaceutical film coatings, highlighting the main contributions made and outlining the key challenges ahead

Abstract-Statistical signal processing for quantitative assessment of pulsed terahertz imaging of human breast tumors

 Tyler Bowman, Tanny Chavez,  Kamrul Khan,  Avishek Chakraborty,   Jingxian Wu,  Keith Bailey,  Magda El-Shenawee,

http://ieeexplore.ieee.org/document/8067265/

This paper presents utilization of pulsed terahertz imaging to detect and assess the margins of excised human breast tumors. The freshly excised bulk tissue and the block of the same tissue fixed in formalin and embedded in paraffin (FFPE) are scanned using the reflection imaging module. The results show that while the THz images of block tissue demonstrate strong contrast between cancerous and fibroglandular (normal) regions, the contrast is less strong in the images of freshly excised bulk tissue. This could be due to remains of blood and presence of air bubbles in the specimen. To validate the THz images, we develop signal processing and statistical data analysis techniques based on image morphing and Bayesian modeling. The results are quantified in the form of receiver operating characteristic (ROC) curves.

Abstract-Multispectral UV imaging for determination of the tablet coating thickness

• Anna Novikova^a, 
• Jens M. Carstensen^b, 
• J. Axel Zeitler^c, 
• Thomas Rades^d, 
• Claudia S. Leopold^a, , 

• ^a Division of Pharmaceutical Technology, Department of Chemistry, University of Hamburg, Bundesstraße 45, 20146 Hamburg, Germany
• ^b Department of Applied Mathematics and Computer Science, Technical University of Denmark, Richard Petersens Plads Building 321, 2800 Lyngby, Denmark
• ^c Department of Chemical Engineering, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA, United Kingdom
• ^d Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark

http://www.sciencedirect.com/science/article/pii/S0022354917300886

The applicability of off-line multispectral ultraviolet (UV) imaging in combination with multivariate data analysis was investigated to determine the coating thickness and its distribution on the tablet surface during lab scale coating. The UV imaging results were compared with the weight gain measured for each individual tablet and the corresponding coating thickness and its distribution measured by terahertz pulsed imaging (TPI). Three different tablet formulations were investigated, two of which contained UV active tablet cores. Three coating formulations were applied: Aquacoat^®ECD (a mainly translucent coating) and Eudragit^® NE (a turbid coating containing solid particles). It was shown that UV imaging is a fast and non-destructive method to predict individual tablet weight gain as well as coating thickness. The coating thickness distribution profiles determined by UV imaging correlated to the results of the TPI measurements. UV imaging appears to hold a significant potential as a PAT tool for determination of the tablet coating thickness and its distribution resulting from its high measurement speed, high molar absorptivity and a high scattering coefficient, in addition to relatively low costs.

Evaluation of Coating Properties of Enteric-Coated Tablets Using Terahertz Pulsed Imaging

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• Masahiro Niwa 1 
• Yasuhiro Hiraishi 1 
• Katsuhide Terada 2

http://www.pharmagateway.net/ArticlePage.aspx?DOI=10.1007/s11095-014-1314-6
Purpose

Enteric coatings are used to reduce gastrointestinal side effects and control the release properties of oral medications. Although widely used, the effect of formulation and process conditions on physicochemical and functional properties of enteric coatings remains unclear.

Methods

Terahertz pulsed imaging (TPI) was employed to evaluate the coat properties of enteric coated tablets (ECTs) with various acid resistance. Other analytic methods, such as loss on drying, scanning electron microscopy and X-ray computed tomography were then used to validate the relationships established among 4 TPI-derived parameters and the physicochemical properties of enteric coatings.

Results

Weight gain measurement did not provide any information to assess acid resistance of enteric coating, whereas four TPI-derived parameters non-destructively reflected the coating properties such as thickness, coat uniformity, density, and water distribution, allowing the identification of the causes of poor acid resistance in certain ECT batches using a single measurement. These parameters also revealed the effect of coating conditions; in particular, coating under dry conditions led to less dense and nonuniform coatings with poor acid resistance.

Conclusion

We demonstrated the utility of TPI to identify structural defects within ECTs with poor acid resistance. TPI-derived parameters can aid in formulation development and quality control of ECTs.