An evaluation of content uniformity of tablets prepared by quasi-continuous drug coating using near infrared and Raman spectroscopy

In recent years, there has been increased interest in continuous manufacturing to improve manufacturing efficiencies. The Supercell coater is an example of a quasi-continuous coater capable of integration as an in-line unit operation for handling sub-batches of tablets. The aim of this study was to evaluate the drug-content uniformity of tablets prepared by quasi-continuous drug coating using the Supercell coater. In addition, near infrared (NIR) and Raman spectroscopy were evaluated in parallel as process analytical technology tools for the monitoring of drug content in the coated tablets. Results showed that the Supercell coater was capable of coating tablets continuously with interbatch relative standard deviations of 2.2-4.9%, as measured by NIR spectroscopy and 1.4-5.0%, as measured by Raman spectroscopy. Both NIR and Raman spectroscopic methods were shown to be useful as non-destructive and rapid at-line monitoring tools to evaluate the drug-content uniformity of coated tablets. The spectra obtained from future exhaustive online measurements of tablets may be used as product fingerprints for real-time quality assurance.