Skip to main content
Have you had challenges with CM adhesion/cohesion? Experts are discussing this topic in the Oral Solid Dosage Group,, broken out into the following key areas: conveying, feeding, transfer hoppers, and transition pipes. Learn from their experience by reading the full conversation here:

Implementation of a fully integrated CM direct compression and coating process at a commercial pharmaceutical facility - Part 2: PAT and RTD results for normal operational conditions batches.

By Rosas, JG; Brush, P; Thompson, B; Miller, C; Overton, P; Tugby, N; Stoliarskaia, D; Hurley, S; Ramasamy, M; Conway, SL

Published on CMKC


This is the second of two articles detailing the continuous manufacturing (CM) development and implementation activities for an marketed product which have been realized in novel, qualified equipment, using validated control strategy elements to enable manufacture of batches under current good manufacturing practices (cGMP) and compliant with data integrity principles. Here, the application of process analytical technologies (PAT) and automation tools on batches produced under normal operational conditions is reviewed. The results from residence time distribution (RTD) models for predicting API concentration, in-line near infrared (NIR) testing of blend uniformity (BU) and at-line NIR spectroscopy analysis of core tablet concentration and tablet identity for real-time release testing (RTRT) are discussed. The influences of process equipment and design choices on NIR and RTD model variability, as well as the use of the PAT tools for monitoring the evolving properties understanding of CM process development, such as overcoming flow instabilities, is described. Results demonstrate that the RTD and NIR models developed and validated are robust to operating conditions and are critical for assuring steady state control of the continuous manufacturing process. Finally, the NIR and RTD model lifecycle, including procedures for necessary and normal model upgrades in a cGMP production environment, are presented.


International Journal of Pharmaceutics. Volume 636, 2023, 122814



Type of publication

Peer-reviewed journal


  • Merck & Co. Inc
  • Merck Sharp & Dohme (UK) 

Article Classification

Research Article

Classification Areas

  • Intermediate
  • Process Analytical Technologies