Process monitoring of ultrasound compaction as a small-scale heating process

• Published in: European journal of pharmaceutical sciences Vol. 49; no. 5; pp. 829 - 835
• Main Authors: Ueda, Hiroshi, Kawai, Akira, Hayashi, Takashi, Ida, Yasuo, Kakemi, Masawo, Tozuka, Yuichi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 16.08.2013
• Subjects: Drug Compounding - methods; Glass transition temperature; Heating; Polymers - chemistry; Process monitoring; Small-scale heating process; Sonication; Transition Temperature; Ultrasound compaction; Process monitoring; Ultrasound compaction; Glass transition temperature; Small-scale heating process
• ISSN: 0928-0987; 1879-0720
• DOI: 10.1016/j.ejps.2013.06.001

Ultrasound compaction is a simple small-scale heating process. The aim of this study was to elucidate the polymer phase transition process during ultrasound compaction by process monitoring. Morphological change with heat occurs when ultrasound energy is supplied. Monitoring of the process revealed changes in both punch position and the pressure of the die in terms of the polymer’s phase transition process. The optimum ultrasound energy for complete transition could be detected by a sudden increase in the pressure on the lower punch. Such optimum energy clearly depended on the polymer’s glass transition temperature (Tg), suggesting that Tg is the predominant parameter in the ultrasound compaction process. Optimization of ultrasound energy based on monitoring profiles is a promising way to obtain a desirable product by thermoplastic treatment with minimal thermal degradation due to excess supply of energy.