Ultrasound-Assisted Compression

Two main objectives are pursued nowadays by means of the application of ultrasound-assisted compression ... 

Further research is needed in the area of ultrasound-assisted compression of pharmaceutical powders, including a higher number of drugs and excipients. 

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

A. Aguilcff-De-Leyvci, T. Con9 ilves-Araujo, V. Daza and 1. Caraballo, A new deferiprone controlled relccise system obtcuned by ultrasound-assisted compression, Pharm. Dev. Technol, 19 (6) 728-734,2014. 

Ultrasound-assisted powder compression has been widely employed in metallurgy as well as in the plastic and ceramic industries [84], The first references in the pharmaceutical industry are two patents in 1993 [85] and 1994 [86], Since then, some papers have presented experimental data in this field [45,87-92],... 

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. 

For the last several years, mass spectrometry with atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) have determined the trends in the analysis of dyes. Since 1987, various variants of ESI have been used in which droplet formation was assisted by compressed air,[1,2] temperature (e.g. Turbo Ion Spray ) or ultrasound, and they were able to handle flow rates up to 1 2 ml min This made a combination of analytical RPLC and ESI easily and widely used. The reason why it often was (and is) used instead of a traditional UV-Vis detector is the better sensitivity and selectivity of MS in comparison with spectrophotometric detection. Apart from these advantages, MS offers easily interpretable structural information. However, various... 

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