Audible acoustic emission data analysis for active pharmaceutical ingredient concentration prediction during tableting processes

Comparative study on the real-time monitoring of a fluid bed drying process of extruded granules using near-infrared spectroscopy and audible acoustic emission

The process of fluidized bed drying of granules was comparatively evaluated by on-line real-time measurements of granule moisture content (MC) using near-infrared spectroscopy (NIR) and audible acoustic emission (AAE). The extruded granules were prepared by kneading a powder blend containing lactose, starch, crystalline cellulose, and riboflavin, with water. The MC of the granules (while they were dried at 35 °C in a fluidized bed dryer) was monitored simultaneously with NIR and AAE. The prediction accuracy of the NIR and AAE using partial least squares (PLS) was verified by measuring MC of the granules. The best calibration models following NIR and AAE evaluations consisted of five latent variables with correlation coefficients of 1.000 and 0.998 and root mean square error of 0.259 and 0.615, respectively. As a result of external verification, the accuracy of MC analysis by AAE was slightly lower than that of NIR; however, it was still applicable in practice. Furthermore, the end point of fluidized bed drying process was automatically determined using the PLS discriminant analysis. From the above results, it can be concluded that the AAE-mediated granule drying process can be monitored with sufficient accuracy (compared with NIR).

[Advances in Pharmaceutical Manufacturing Process Management -From Physical Pharmaceutics to Automatic Pharmaceutical Production]

Since entering graduate school 43 years ago, I have been studying physical pharmaceutics with a focus on the effects of environmental factors on pharmaceutical properties of solid oral dosage forms during the manufacturing process. I have reported on changes in the characteristics of pharmaceutical products during manufacturing processes, such as grinding, mixing, granulation, and tableting owing to complicated phenomena based on chemical reactions or the crystalline polymorphic transitions of bulk drugs and excipients. To develop modern pharmaceutical manufacturing processes based on process analysis technology (PAT) as a next generation good manufacturing practice, real-time monitoring was introduced in these processes using a non-destructive analytical method, such as the near-infrared spectroscopy combined with chemometrics. Many case studies related to the mixing, granulation, tableting, and coating processes involving PAT have been reported. In those studies, I focused on clarifying the physical and chemical mechanism through "design space" representation. Additionally, non-destructive analytical methods, including X-ray computed tomography, audible acoustic emission, Raman spectroscopy, terahertz spectroscopy, and infrared thermal imaging analysis were applied as novel candidate analytical methods to the pharmaceutical process to monitor critical quality attributes. To achieve this purpose in various pharmaceutical dosage forms, I have been attempting the assembly of a modern manufacturing process managed through a "design space" paradigm involving in-line monitoring using novel analytical methods, multivariate analyses, and feed-back systems.

Kinetics Study of Cocrystal Formation Between Indomethacin and Saccharin Using High-Shear Granulation With In Situ Raman Spectroscopy

Pharmaceutical manufacturing processes are necessary to make solid dosage form even in cocrystal formation. In an effort to reduce the number of unit operations, high-shear wet granulation with cocrystallization system was proposed. In the present study, indomethacin-saccharin was chosen as a model compound, and the cocrystal formation kinetics was investigated during the consistent process. The role of each initial indomethacin crystal state (γ-form, α-form, or amorphous) for the kinetics was explored using in situ Raman spectroscopy with multivariate curve resolution by alternating least-squares analysis as a chemometrics. Obtained granules were characterized by X-ray diffraction and tablet dissolution testing. The Raman peaks assigned to indomethacin-saccharin cocrystal were increased with granulation when ethanol was used as a binding solvent. In addition, the reaction kinetics of run samples which had different indomethacin forms was distinguished by best fitting using Avrami-Erofeev or Ginstling-Brounshtein model. The kinetic variance depended on the initial thermodynamic state of indomethacin because they had a different crystallization mechanism for the cocrystal. The scalable and feasible granulation method is required in the pharmaceutical industry.