title: Acoustic monitoring of a fluidized bed coating process.
abstract: The aim of the study was to investigate the potential of acoustic monitoring of a production scale fluidized bed coating process. The correlation between sensor signals and the estimated amount of film applied and percentage release, respectively, were investigated in coating potassium chloride (KCl) crystals with ethylcellulose (EC). Vibrations were measured with two different types of accelerometers. Different positions for placing the accelerometers and two different product containers were included in the study. Top spray coating of KCl was chosen as a 'worst case' scenario from a coating point perspective. The acoustic monitoring has the potential of summarising the commonly used means to monitor the coating process. The best partial least squares (PLS) regressions, obtained by the high frequency accelerometer, showed for the release a correlation coefficient of 0.92 and a root mean square error of prediction (RMSEP) of 5.84% (31-82.8%), and for the estimated amount of film applied a correlation coefficient of 0.95 and RMSEP of 0.52% (0.6-6%). The results of the preliminary investigation are considered promising. There is however a need for further investigations on sampling procedures and product characterisation before a final conclusion on the applicability of acoustic monitoring can be made.
authors.affiliation: Department of Pharmacy, University of Tartu, Nooruse 1, 50411 Tartu, Estonia.
authors.forename: Kaisa
authors.initials: K
authors.lastname: Naelapää
authors.forename: Peep
authors.initials: P
authors.lastname: Veski
authors.forename: Joan G
authors.initials: JG
authors.lastname: Pedersen
authors.forename: Dan
authors.initials: D
authors.lastname: Anov
authors.forename: Pia
authors.initials: P
authors.lastname: Jørgensen
authors.forename: Henning G
authors.initials: HG
authors.lastname: Kristensen
authors.forename: Poul
authors.initials: P
authors.lastname: Bertelsen
mesh_terms: D000054:Acceleration; D000162:Acoustics; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods; D016018:Least-Squares Analysis; D011189:Potassium Chloride / Q000737:chemistry; D011237:Predictive Value of Tests; D025341:Principal Component Analysis; D012015:Reference Standards; D015203:Reproducibility of Results; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D013997:Time Factors; D014732:Vibration
chemical_list: D003692:Delayed-Action Preparations; D011189:Potassium Chloride; C013517:ethyl cellulose; D002482:Cellulose