Industrial Applications of Online Monitoring of Drying Processes of Drug Substances Using NIR

Abstract

Drying is an important part of manufacturing processes in the chemical and pharmaceutical industry. The product quality often depends on the drying conditions and efficiency. Moreover, this unit operation frequently represents the bottleneck of the whole process. Therefore, online monitoring of the drying operation can lead to a significant improvement of the cycle time as well as to a reduction of the analytical work and costs. This paper demonstrates the effectiveness of NIR spectroscopy to control drying processes on an industrial scale. The examples shown in this study are realized using different kinds of dryers (filter dryer, paddle dryer, and spherical dryer) and various solvents (water and organic solvents). The spectral data are evaluated using multivariate calibration methods (partial least squares regression). These studies show that the solvent concentrations determined using NIR are in good agreement with the reference analyses. Moreover, the direct measurement in the powder allows stopping the drying process at a given residual solvent concentration (which is crucial in certain processes, e.g. to obtain specific hydrate forms). All together, the implementation of NIR for online monitoring of drying processes leads to a significant optimization of plant equipment utilization and to a higher throughput while reducing the risk of out-of-specifications batches.

Review on Conveyor Systems and Thermography

“…In business plans of extensive band dryers, it is imperative to guarantee uniform circulation of the item on the band and furthermore uniform dissemination of the wind stream inside the chamber of the dryer to guarantee uniform item wetness content [45 -47]. Similarly dryers also play a foremost role in pharmaceutical industries [92], agricultural products [17], food industry [93], marine products [94], fruits drying [94,95,96,97], porous bodies drying [98], timber drying [99], cereals drying [100,101], paper drying [102,103,107], fabric drying [104], cement industry [105,106], printing, drug drying [109], sludge and faecal materials from sanitation processes [108], laundry [110], etc. Dryer installation is little expensive but is worthy enough to provide best results of removing moisture from resources.…”

Prozessanalytik bei der Zerstäubungstrocknung – Beispiele und Herausforderungen

“…Restfeuchte und ABM‐Gehalt des Pulvers können sowohl online als auch offline mittels NIR‐Spektroskopie verfolgt werden (Abb. 7) 19. Die Bestimmung der Restfeuchte ist bei Messzeiten von unter einer Minute mit einer Genauigkeit von ± 0,3 % leicht möglich und damit gut für die Prozesssteuerung geeignet.…”

Process Monitoring of Moisture Content and Mass Transfer Rate in a Fluidised Bed with a Low Cost Inline MEMS NIR Sensor

“…For instance, complementary compositional and physical information could be obtained for several drug manufacturing stages before attempting to replace conventional quality control or research analytical systems. A specific example is the monitoring of moisture content, a control parameter used in several stages of the solid-dose form production process (5), normally required for milling and blending (12,13), granulation (14,15), tablet coating (16), and dying, particularly fluidised bed granule drying, which has been extensively studied (17)(18)(19)(20).…”