Ultrasound-assisted tableting

Mechanical Pressure This pressure is exerted by the punches of the ultrasound-assisted tableting machine. This is the main compression mechanism when low ultrasonic energies are employed (below 25 J in the mixtures studied by... 

The peak temperature obtained for low ultrasonic energy (25 J) is below 80 °C, whereas for high energies (125-150 J) it is above 140 °C. In mixtures of keto-profen with acrylic polymers [90], the increase in temperature was slightly lower. In this respect it must be mentioned that a recent modification of the ultrasound-assisted tableting machine that involves the suppression of Teflon isolators in contact with the powder must result in a faster decrease in temperature inside the compression chamber. Thermal effects can cause the total or partial fusion of some components of the formulation. Nevertheless, in the assayed controlled-release formulations, the components are usually below its melting points. 

Rodriguez, L., Cini, M., Cavallari, C., Passerini, N., Fabrizio Saettone, M., Fini, A., and Caputo, O. (1998), Evaluation of theophylline tablets compacted by means of novel ultrasound-assisted apparatus, Int. J. Pharm., 170, 201-208. 

If it is desirable to overcome capping and lamination during the tableting process, the use of ultrasound-assisted presses could be a reliable solution. However, use this technique is still very recent since reports in the scientific literature extend only over the last decade [33],... 

Critical Points in Matrix Tablets Prepared by Ultrasound-Assisted Compression... 

To harness the full potential of amorphous systems for all types of chemical compounds, alternate technologies are constantly being added to the toolbox. Ultrasonic-assisted compaction is a modified tabletting process that can provide heat, pressure, and shear due to ultrasonic energy to the powder mixture during compaction. The application of ultrasound to solubility enhancement is based on the fusion method and in some ways mimics the extrusion process (Fini et al. 1997 Sancin et al. 1999). The ultrasonic frequency vibration is applied at the same time as compaction force. The key features of the technology include ... 

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