Liquisolid technology, as a promising approach for bioavailability enhancement, has received increasing attention in recent years. However, literature reports addressing the challenges for its industrial application, particularly those related to compaction behavior of liquisolid systems, are scarce. The aim of this study was to investigate the influence of process parameters and formulation variables on the flowability, wetting, and compaction properties of the liquisolid systems prepared in a fluid bed processor. The experiments with microcrystalline cellulose, as a carrier, were performed according to 23 full factorial design. The effects of liquid content, spray air pressure, and liquid feed rate on the properties of liquisolid systems were investigated. Liquisolid admixtures with microcrystalline cellulose were compared with those prepared with novel carriers, Fujicalin® and Neusilin® US2. "Out-die" Heckel, modified Walker, and Kuentz-Leuenberger models were used to analyze the compressibility of liquisolid admixtures. The results obtained showed that an increase in liquid content (in the range of 10 to 15%) led to a decrease in flowability of liquisolid admixtures with microcrystalline cellulose, as well as more pronounced influence of spraying conditions. On the other hand, higher liquid content led to higher compressibility. Fujicalin® and Neusilin® US2 liquisolid admixtures were found to have superior flowability and compressibility in comparison with those with microcrystalline cellulose, despite the considerably higher liquid load (50-55% liquid content in Neusilin® US2 compacts). Acceptable compactibility of the investigated liquisolid systems was observed. The fluid bed processor was shown to be suitable equipment for production of liquisolid systems, but with careful adjustment of process parameters.
Keywords: Heckel; Kuentz-Leuenberger; Walker; fluid bed; liquisolid compacts.