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Enzymatic conversion of galactosylated glycans by gut bacteria : Structural and functional characterisation of carbohydrate-active enzymes

The human gut microbiome is a highly complex environment, where a myriad of intricate microbiota-microbiota and microbiota-host interactions occur. The human gut microbiota has been associated with both health and disease. The research presented in this thesis focuses on investigating how the butyrate-producing human gut bacterium Roseburia hominis A2-183 (R. hominis) processes β-mannan oligosacch

Morphology development during single droplet drying of mixed component formulations and milk

We report on the influence of selected components and their mixtures on the development of the morphology during drying of single droplets and extend the results to the morphology of whole milk powder particles. Sessile single droplet drying and acoustic levitation methods were employed to study single droplet drying. The influence of carbohydrates (lactose and maltodextrin DE12) and proteins (mic

Freeze-dried and re-hydrated liquid crystalline nanoparticles stabilized with disaccharides for drug-delivery of the plectasin derivative AP114 antimicrobial peptide

Liquid crystalline nanoparticles (LCNPs), e.g. cubosomes and hexosomes, are receiving more and more attraction as drug delivery vehicles. Dry powder formulation that forms LCNPs upon hydration can be advantageous to make new routes of administration accessible. In this work, we investigate use of three disaccharides (lactose, trehalose and sucrose) as protective matrices for glycerol monooleate ba

Milling induced amorphisation and recrystallization of α-lactose monohydrate

Preprocessing of pharmaceutical powders is a common procedure to condition the materials for a better manufacturing performance. However, such operations may induce undesired material properties modifications when conditioning particle size through milling, for example. Modification of both surface and bulk material structure will change the material properties, thus affecting the processability o

AFM Colloidal Probe Measurements Implicate Capillary Condensation in Punch-Particle Surface Interactions during Tableting

Adhesion of the powders to the punches is a common issue during tableting. This phenomenon is known as sticking and affects the quality of the manufactured tablets. Defective tablets increase the cost of the manufacturing process. Thus, the ability to predict the tableting performance of the formulation blend before the process is scaled-up is important. The adhesive propensity of the powder to th

Porous calcium carbonate as a carrier material to increase the dissolution rate of poorly soluble flavouring compounds

Two different food grade functionalised porous calcium carbonates (FCC), with different pore size and pore size distributions, were characterised and used as carrier materials to increase the dissolution rate of poorly soluble flavouring compounds in aqueous solution. The loading level was varied between 1.3% by weight (wt%) and 35 wt%, where the upper limit of 35 wt% was the total maximum loading

Determination of interfacial amorphicity in functional powders

The nature of the surfaces of particles of pharmaceutical ingredients, food powders, and polymers is a determining factor for their performance in for example tableting, powder handling, or mixing. Changes on the surface structure of the material will impact the flow properties, dissolution rate, and tabletability of the powder blend. For crystalline materials, surface amorphization is a phenomeno

Effect of shell microstructure on oil migration and fat bloom development in model pralines

This study investigated the influence of shell microstructure on oil migration and fat bloom development in chocolate model systems. The microstructure of the model shells was varied by means of tempering or seeding cocoa butter and the addition of non-fat particles. Further, the impact of different storage conditions was studied. By using a set of novel analytical techniques the migration rate co

Pulmonary delivery of antimicrobial peptides

Anna Fureby, PhD, Group Manager & Senior Scientist, Life Science, and Ulla Elofsson, PhD, Senior Scientist, both of SP Technical Research Institute of Sweden, and Per Gerde, PhD, Chief Scientific Officer, Inhalation Sciences Sweden, discuss the serious problem of antibiotic resistance and the potential role of antimicrobial peptides in the treatment of resistant bacterial strains. For pulmonar

Tablet mechanics depend on nano and micro scale adhesion, lubrication and structure

Tablets are the most convenient form for drug administration. However, despite the ease of manufacturing problems such as powder adhesion occur during the production process. This study presents surface and structural characterization of tablets formulated with commonly used excipients (microcrystalline cellulose (MCC), lactose, mannitol, magnesium (Mg) stearate) pressed under different compaction

Aqueous Two-Phase Systems for Microencapsulation in Food Applications

This chapter deals with aqueous two-phase systems, which are formed spontaneously when two polymers are mixed in water as a common solvent. Such phase-separated systems have potential as microencapsulation systems, although the major focus in research has been (bio)separation applications. Added components, such as proteins, large molecules, whole cells, and emulsion droplets, tend to partition pr

Relationships between solid dispersion preparation process, particle size and drug release - An NMR and NMR microimaging study

Solid dispersion tablets prepared by either spray drying or rotoevaporation and exhibiting different grain and pore sizes were investigated under the process of hydration-swelling-gelation. 2H and 1H NMR microimaging experiments were used to selectively follow water penetration and polymer mobilization kinetics, respectively, while the drug release kinetics was followed by 1H NMR spectroscopy. The

Polymer-drug interactions and wetting of solid dispersions

We demonstrate the ability of drugs to influence the wetting of solid dispersion tablets in unexpected ways. Five model drugs of different water solubility and ability to interact with the involved polymers were incorporated in hydrophilic polymer matrices, made of either hydroxypropyl methylcellulose (HPMC) or polyvinyl pyrrolidone (PVP). The physical mixtures of all combinations of drug and poly

Approaches to encapsulation of active food ingredients in spray-drying

Microencapsulation can be used to improve the stability and control the release of dried active food ingredients such as flavors, enzymes, probioticas and oxidation sensitive oils. Spray-drying can be used for encapsulation and powder generation in one step by utilizing different phenomena that occur during drying. Dry emulsion is a classic way to supply encapsulated flavors and protect oxidation

Adsorption of pharmaceutical excipients onto microcrystals of siramesine hydrochloride : Effects on physicochemical properties

A common challenge in the development of new drug substances is poor dissolution characteristics caused by low aqueous solubility. In this study, microcrystals with optimized physicochemical properties were prepared by precipitation in the presence of excipients, which adsorbed to the particle surface and altered particle size, morphology, and dissolution rate. The poorly water-soluble drug sirame