Zeljko Knez

University of Maribor, Slovenia

Title: High pressure applications for design of pharmaceutical products

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Biography

Zeljko Knez, born on August 26, 1954 in Maribor, Ph.D. (science), M.Sc., B.Sc. (Eng.; Chem.)., Professor of Chemical Engineering at the Faculty of Chemistry and Chemical Technology of the University of Maribor.

In 1973, he graduated from the 1st gymnasium (secondary school) in Maribor with highest honours. He continued his studies in chemical technology at the University of Maribor, and graduated with a B.Sc. in 1977. He completed his master's degree in chemical technology at the Faculty of Natural Sciences and Technology of the University of Ljubljana in 1979. From 1977 to 1981, he was employed in TKI Pinus Ra?e, where he performed research in the field of organic synthesis. Based on his research, the synthesis of biologically active substances on an industrial scale was subsequently realized. He received his Doctorate from the University of Maribor in 1984. 

In 1981, he was employed at the University of Maribor, Department of Chemistry, as Teaching Assistant; in 1985 he was appointed  Assistant Professor in Chemical Engineering, in 1990 as Associate, and in 1995 as Full Professor.

In 1985, he founded the Laboratory for Separation Processes at the Faculty of Chemistry and Chemical Technology, University of Maribor, and was the first Slovenian researcher of supercritical fluids. Later, he helped establish research groups and industrial laboratories (TKI Pinus Ra?e, Vitiva Markovci).

Continuing his postdoctoral studies, he attended the Department of Food Engineering, University of Agriculture, Wageningen (NL), and from 1990-97, worked for several months as a visiting researcher at Technische Chemie II, at the University of Erlangen - Nuremberg.

Abstract

High pressure technologies involving sub and supercritical fluids offer the possibility to obtain new products with special characteristics or to design new processes in pharma industry, which are environmentally friendly and sustainable. There are several high pressure processes using sub- and supercritical fluids which are already developed to the commercial scale, like extraction of solids and liquids, particle formation, high pressure sterilization, thin-film deposition for orthopedic implants, separations of value-added products from fermentation broths in biotechnology fields and as the solvent in a broad range of synthesis. All of these applications lead to sustainable manufacturing methods that are not only ecologically preferable but also give the products with very special properties.

For the design of all high pressure processes, data are required on the operating parameters, the type and quantity of the solvent, the recirculation rate and energy consumption. This information can be obtained from phase equilibrium and mass transfer measurements. However, scientific literature offers some of these data, measured at a variety of pressures and temperatures, for several pure compounds.

An overview of the success of micro- and nano-forms fabrication using environmentally friendly supercritical fluid technologies for processing and incorporation of active compounds will be presented. Several new approaches will be described in detail, namely micronization for the production of micro- and nano-sized particles, supercritical drying for the production of aerogels, supercritical foaming and supercritical solvent impregnation, as well as currently available drug delivery data for these formulations. The presentation will also give a limited overview of future perspectives in developments of processes and applications of different sub-and supercritical fluids as green processing media in pharma industry.