Evaluation of critical process parameters for inter-tablet coating uniformity of active-coated GITS using Terahertz Pulsed Imaging.

The aim of this study was the evaluation of critical process parameters (CPP) for inter-tablet coating uniformity in an active pan coating process using nondestructive Terahertz Pulsed Imaging (TPI). Coating uniformity was assessed by calculating the coefficient of variation (CV) of coating thickness measured by TPI, and the CV of API content measured by high performance liquid chromatography (HPLC). A design of experiments (DoE) was performed at pilot scale with drum load, drum speed, spray rate, run duration and spray pressure as factors.

Evaluation of critical process parameters for intra-tablet coating uniformity using terahertz pulsed imaging.

The purpose of this study was to evaluate the intra-tablet coating uniformity and the identification of critical process parameters in an active pan coating process using terahertz pulsed imaging (TPI). A design of experiments (DoE) was performed with drum load, drum speed, spray rate, run duration and spray pressure as factors. Different measures of intra-tablet uniformity were investigated: the average thickness on the individual tablet faces, spatial variation in layer thickness over the tablet surface, and the coefficient of variation (CV(intra)).

Critical factors in the measurement of tablet film coatings using terahertz pulsed imaging.

The present work gives an insight into some key measurement and signal processing considerations in terahertz pulsed imaging (TPI). TPI is increasingly used for the measurement of the spatial variation of coating thickness on coated solid dosage forms. The potential of TPI for the assessment of coating thickness distributions and the use in process development is described in recent literature.

Validation of Terahertz coating thickness measurements using X-ray microtomography.

Terahertz pulsed imaging (TPI) is a recently developed nondestructive and noncontact method to measure the coating thickness of coated pharmaceutical tablets. The method requires no calibration in order to resolve the coating structure of tablets. The relative coating thickness over a tablet surface or between different tablets of the same batch can be determined with high precision.

Prediction of dissolution time and coating thickness of sustained release formulations using Raman spectroscopy and terahertz pulsed imaging.

Raman spectroscopy was implemented successfully as a non-invasive and rapid process analytical technology (PAT) tool for in-line quantitative monitoring of functional coating. Coating experiments were performed at which diprophylline tablets were coated with a sustained release formulation based on Kollicoat SR 30 D. Using PLS a multivariate model was constructed by correlating Raman spectral data with the mean dissolution time as determined by dissolution testing and the coating thickness as measured by terahertz pulsed imaging.