The mechanisms of the transformation from salt to free form drug during processing of a model drug are investigated with special emphasis on the interplay of salt solubility and pH of the excipients. The obtained results can provide a reliable guidance for selecting excipients for robust formulation design of solid dosage pharmaceuticals in salt forms.

A novel approach to discover new pharmaceutical cocrystals in the early development stage is applied to develop cocrystals of piracetam with some aliphatic diacids. A 1:1 cocrystal of piracetam and glutaric acid is screened by a mechanochemical method and the process of cocrystal formation during solution-mediated phase transformation is discussed.

Controlling crystal polymorphism is a challenging task. The effect of crystallization conditions on the crystal polymorphs of indomethacin was studied by evaporation crystallization from a free solvent surface and in a mesoporous solid material. The approach was based on a mass transfer model of evaporation and experimental solvent flux measurements were used for model evaluation.

The scale-up of crystallization processes is an important research area and has been studied for many years. The scale-up of a fluidized bed crystallizer was studied based on the solid spatial concentration distribution in the crystallizer. A strategy for the scale-up of the crystallization process was suggested based on the different states of solid suspension.

The population balance equation (PBE) model for crystallization and the solution-mediated transformation (SMT) of the metastable α-DL-methionine into the stable γ-DL-methionine in water was derived. The crystallization and dissolution kinetics of each polymorph were applied to the PBE model and compared with the results from the SMT experiment.

The effect of polyethylenimine (PEI) addition on nucleation and growth of SrSO₄ is determined and a simple kinetic model is proposed. Time-dependent behaviors of crystal size and crystal number are statistically analyzed by a nonlinear least-square program. Kinetic aspects under the condition of obtaining monodisperse crystals are discussed.

First studies on solution-mediated phase transformation of a hydrate (form I) to its anhydrous form (form III) of donepezil hydro-chloride are reported. Mechanisms involved in this process are investigated by in situ and offline measurement technologies. A tentative correlation between thermodynamic properties and phase transformation is presented.

An experimental investigation of the application of a nephelometric probe to study nucleation kinetics is reported. The nephelometric signal proved to be proportional to the surface of the solids in suspension. It allowed to accurately detect the metastable zone width and the induction time and to monitor the first period of time after nucleation.

Ultrasonic technology shows great potential in the crystallization industry with respect to the effects on crystal size distribution and morphology of the products. A novel combination of conventional reactive crystallization process and insonated disturbance is introduced to prepare uniform cloxacillin benzathine crystals with fewer aggregates.

The effects of seed addition temperature, seed surface area, seed loading, and seed origin on the granulometric properties, crystal size distribution, and polymorphism of the model amino acid glycine prepared by batch cooling crystallization were investigated. Polymorphism was examined by differential scanning calorimetry and X-ray diffraction analysis.

The crystal structure of tetracycline hydrochloride was predicted by single-crystal data via Bravais-Friedel-Donnay-Harker and modified attachment energy models. Based on simulations of the pure crystal, morphological modifications induced by solvents were examined by calculation of interaction energies between solvents and each cleaved crystal surface.

The phase equilibria of the system Mg²⁺, Ca²⁺//Cl^–, SO₄^2–-H₂O at different temperatures are decisive for producing MgSO₄·7H₂O using the mother liquid origin in magnesium-based wet flue gas desulfurization. The solubility of this quaternary system is evaluated by means of isothermal solution saturation.

Different dissolution-precipitation methods served for modification of a disposable iron-based catalyst, red mud. The resulting materials were evaluated as catalysts for the slurry-phase catalytic hydrocracking of vacuum residue. Red mud activated by phosphoric acid treatment exhibited the best performance due to the caused particle size reduction.

Modified Li-Al layered double hydroxides are effective solid catalysts for transesterification of soybean oil (SBO) and ethylene glycol. They can be separated, reused, and regenerated easily and they have the potential to simplify the production process by using continuous packed-bed reactors. The SBO fatty acid esters products were anchored with end hydroxyl groups by ethylene glycol, which provide reaction sites for further modification of long chains.

Commercially valuable glutaminase produced from Zygosaccharomyces rouxii NRRL-Y 2547 was partitioned in polyethylene glycol (PEG)-salt aqueous two-phase systems. Effects of salt type and concentration, PEGs with different molecular weight, and tie line lengths on partitioning and purification factor were evaluated and defined for optimum results.

A microreactor setup with internal recirculation operated in continuous mode was used to demonstrate Beckmann rearrangement of cyclohexanone oxime dissolved in cyclooctane with oleum to ϵ-caprolactam. At 100 °C, the conversion of cyclohexanone oxime was complete; selectivity towards ϵ-caprolactam was 99 %. However, cyclooctane as solvent reduced the purity of the produced ϵ-caprolactam.

The effects of lifter arrangement and operation conditions on power consumption in a rotating-drum bioreactor (RDB) were investigated. Empirical correlations of the power number related to reactor configuration and operation parameters are proposed for liquid and liquid/solid systems to estimate the power consumption for RDB design and scale-up.

The ionic liquid 1-butylimidazole hexafluoride phosphate [bmim]PF₄ is dispersed into water to create an ionic liquid-in-water emulsion which is applied to absorb CO₂. The presence of dispersed ionic liquid droplets significantly enhances the CO₂ mass transfer rate at a gas-liquid interface due to both the shuttle effect and hydrodynamic effect.

Enzymatic polymerization is a powerful tool to synthesize electronically and optically active polymers. Polyaniline/Ag nanocomposites were obtained using chemical and enzymatic polymerization of aniline based on 2-aminothiophenol-capped Ag nanoparticles. The enzymatic method resulted in smaller nanocomposites with higher thermal stability compared to the chemical method.

Dynamics and control of an enantioseparation by coupled continuous chromatography and subsequent crystallization with recycle of the mother liquor were studied. The combination of both processes can improve significantly the separation efficiency. Some simple control strategies are proposed to compensate unforeseen disturbances and stabilize the process.

CaCO₃ particles can be synthesized by mixing CaCl₂-containing liposome suspension and CO₂-saturated water as demonstrated by scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy. The liposomal reaction system can be applied to the formation of fine CaCO₃ particles through sequestration of CO₂ under optimized conditions.