Micronization of pharmaceutical substances in a spiral jet mill

Many studies have been conducted to help understand the effects of the vari ables involved in jet milling. The first part of this work is an attempt to summarise the results published in the literature concerning horizontal an d vertical jet mills. This focuses on the research of the optimal design of the mills and on the improvement of their performance. Several publication s have been found, concerning mineral grinding. It seemed more interesting to present results on organic crystals' jet milling in the second part of t his paper. The experiments concern three organic substances, and were run o n three different spiral jet mills: Chrispro-Jetmill 50 and 100 and MicronM ills 8 ". The results are presented in terms of specific energy consumption with an adaptation of the correlation proposed by Sarma. These representat ions show that, within the operating energy range and above a critical ener gy value, the creation of specific surface area corresponds to an increase of fine particles production. (C) 1999 Elsevier Science S.A. All rights res erved.