Prediction of Tablet Film-coating Thickness Using a Rotating Plate Coating System and NIR Spectroscopy

Abstract

Abstract. The purpose of this research was to create a calibration model based on near-infrared (NIR) spectroscopy data obtained during a small-scale coating process to predict in-line the coating layer thickness of tablets coated in a side-vented drum coater. The developed setup for the small-scale coating process consisted of a rotating plate with 20 tablets molds that pass a spraying unit, a heating unit, and an in-line NIR spectroscopy probe during one rotation. High-density polyethylene (HDPE) was compressed to flat-faced tablets, and these were coated with a sustained release coating suspension containing Kollicoat IR and Kollicoat SR 30D. The film thickness of these tablets was determined for each tablet individually with a digital micrometer. A calibration model of predicted film thickness versus real-film thickness using PLS regression was developed. This model was tested against in-line NIR data obtained from a coating drum process, in which biconvex HDPE tablets were film-coated with the same filmcoating suspension. The model predicted a final coating thickness of 240 μm, while the measured average thickness (n = 100 tablets) was 210 μm. Taking into account the use of a different setup and differently shaped tablets, it was possible to predict the coating thickness with accuracy comparable to the one of the digital micrometer. Thus, the small-scale rotating plate system was found to be an efficient means of preparing calibration model for a tablet-coating drum process.

Spectroscopic Techniques for Nondestructive Quality Inspection of Pharmaceutical Products: A Review

“…Briefly, the purpose of MSC is to correct the scatter level of the spectra by elimination of the spectral difference of the data (Puchert et al, 2010). SNV is applied to remove the additive baseline and slope variation (Virtanen et al, 2008); the Savitzky-Golay polynomial derivative filters (first-and second-degree polynomial) are used to smoothen the spectra by removing baseline variations and resolving overlapping peaks (Romer et al, 2008). Figure 2 shows the performance of Savitzky-Golay pretreatment for the correction of tablet data (Neves et al, 2012).…”

“…Coatings have a number of advantages and are often used to improve product characteristics such as controlled release of the APIs from the core of a tablet, maintain the shape of the tablet, protect the tablet from environmental influences, lubricate the tablet to ease swallowing, disguise unpleasant tastes, and control the release of drug into the body (Romer et al, 2008). Therefore, the determination of coating parameters, such as layer thickness, uniformity, and reproducibility, are crucial in the quality assurance of controlled release dosage forms (Romer et al, 2008;Sovany et al, 2009;). Traditionally, the coating process is determined offline via HPLC, or by measuring weight gain (Hagrasy et al, 2006).…”

“…Spectroscopic techniques, especially hyperspectroscopy and vibrational spectroscopy (e.g., Raman and near-infrared (NIR) spectroscopy), have various applications in pharmaceutical industries, from tablet manufacturing to final product quality assurance. Quality tests are conducted to analyze the active content (Amigo et al, 2008;Cruz, et al, 2009), blend homogeneity (Lyon et al, 2002;Amigo et al, 2009), coating level (Palou et al, 2012), moisture content (Grohganz et al, 2010), tablet hardness , film thickness (Romer et al, 2008), dissolution profiles (Freitas et al, 2005), and tablet defects (Cairos et al, 2009). The primary advantages of spectroscopic methods are that they are rapid, non-destructive, easy to use, and require less sample preparation.…”

Scale Up of Pan Coating Process Using Quality by Design Principles

“…NIRS can be used as an in‐line PAT instrument to predict the coating thickness and therefore the end point of a coating process. NIRS has been applied off‐line, at‐line, and in‐line in a pan coater . Perez‐Ramos et al developed a NIRS method for in‐line analysis of tablet film coating thickness in a laboratory‐scale pan coater.…”

Near-infrared spectroscopy for nondestructive evaluation of tablets

“…It was observed that the model was able to predict the final coating thickness as accurate as a digital micrometer for biconvex highdensity polyethylene tablets coated with the same suspension. [28] Maurer et al evaluated the film coating process of a tablet by a nondestructive method using NIR. NIR was able distinguish interand intratablet differences by demonstrating different absorbance values.…”