Evaluation of Functional Characteristics of Lactose by Inverse Gas Chromatography

AbstractThe work was focused on the analysis of different batches of the common pharmaceutical excipient lactose using inverse gas chromatography (IGC). Several batches of amorphous (spray dried) and crystalline form of lactose were studied. Surface properties represented by the surface energy and specific (acid-base) interactions between probes and analyzed samples shows batch variations and significant differences between manufacturers and technological processes. The second part of this work was focused on effect of relative humidity and temperature on stability of lactose. The variations of surface energy and specific interactions over time were studied. The changes in surface properties of two batches of lactose-amorphous and crystalline caused by higher relative humidity were measured by IGC. From measured values are obvious different chemical and physical properties of both lactose forms. Negative effect of higher temperature and air humidity lead to changes in surface energy and mainly rapid changes of electron–acceptor and electron-donor surface sites. Lactose monohydrate shows dramatic decrease in the surface energy and in the strength of electron-accepting sites on the contrary of spray dried where the acidity of surface increased

Zvětšování měřítka vlhkého granulačného procesu s vysokým smykem

Mathematical modelling of granulation process represents a useful tool for rules of safe scale-up procedure definition. The same granulator filling ratio, geometrical similitude of granulator and its impeller and chopper, identical peripheral impeller velocity and identical conditions for heat transfer in case of constant all technological and operation parameters are the most important conditions for successful data scale-up

A Multipurpose Micro-pulse Reactor for Studying Gas-phase Reactions

The article is focused on the aspects of using micro-catalytic pulse reactors for studying gas-phase reactions. A literature review includes data regarding different types of micro-catalytic pulse reactor applications in heterogeneous catalysis and the techniques used for estimating kinetic parameters are summarized. The experimental part describes the adaptation of a pyrolysis chromatograph to a micro-catalytic reactor. The mathematical model of a homogeneous pulse carried by the carrier-gas in the plug-flow regime is developed and the assumptions regarding its validity are tested on a model reaction. Three examples describing the application of the technique to non-catalyzed reaction system screening, catalyst screening, and kinetic data measurement followed by estimation of the kinetic quantities of the model reaction by non-linear regression are provided in the article