CHEMENTATOR.

`Supercritical' pills

Polymer coatings on pharmaceuticals protect the active ingredients until the pill is ingested, then they serve to control drug delivery, but the conventional method of hot-coating can harm the active ingredient. Ferro Corp. (Independence, Ohio; ferro.com) has an alternative method that avoids that problem.

Ferro's process, which uses supercritical carbon dioxide to cast drug-polymer particles of tightly controlled diameter, is an adaptation of an existing commercial technique for powder coating. It was described by Ferro project manager Frederick Mandel at the national meeting of the American Institute of Chemical Engineers (AIChE), held in Los Angeles Nov. 12-17. The drug and polymer powders are mixed in a tank of [CO.sub.2] at 200 bars and 31 [degrees] C, then released as a fine spray at 20 bars in an expansion vessel. Pills from the process are being tested in clinical trials.

Cleaning up Bayer liquor

The Bayer process that converts bauxite to …