In recent years, more and more active ingredients have come onto the market that are poorly soluble in water and consequently have low oral bioavailability. One way to increase the solubility and dissolution rate of active ingredients is to prepare solid dispersions by spray drying using different solvents and carriers. The aim of this Master Thesis was to review the literature on studies in which researchers have prepared solid dispersions by spray drying using different carriers and solvents to increase the solubility and dissolution rate of poorly water soluble active pharmaceutical ingredients. Our systematic literature search identified 60 studies from two major databases that were relevant for the purposes of our work. We found that researchers included many different active ingredients in their studies, belonging to different therapeutic groups. Most of the agents belonged to the group of cardiovascular drugs, which are also widely used in daily life. Different solvents, mostly organic, were used to achieve proper dissolution of the drug and carrier. Solid dispersions were prepared using a variety of carriers, with hydrophilic polymeric carriers being the most commonly used, especially PVP and HPMC. Mesoporous carriers were the least used, which was somewhat surprising given their good properties. The surveys also evaluated the solid dispersions prepared. Although very few studies evaluated particle size, most of them produced particles smaller than those of the active ingredient used. Most of the studies also achieved complete amorphization of the active ingredient in the solid dispersion, which remained stable for a period of time under the test conditions used. The process yields were low, but the researchers achieved high percentages of the active ingredient incorporated into the solid dispersion. In almost all the studies, preparation of solid dispersions of poorly water soluble active pharmaceutical ingredients resulted in improvement in dissolution rate as compared to pure form of active pharmaceutical ingredient or physical mixture. Very few articles dealt with the incorporation of solid dispersions into the final dosage form. While there has been a lot of research on the preparation of spray-dried solid dispersions, very little of it has been done with mesoporous carriers, and it would be worthwhile to do more research with them in the future. Although solid dispersions are well researched, the number of formulations on the market is still small, so it would be useful to research them further in the future.
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