@phdthesis{Bernsen2021, author = {Bernsen, Dominik}, title = {Die Auswirkungen einer Umstellung der perioperativen Antibiotikaprophylaxe in der Herzchirurgie: Ein Vergleich von Cephalosporinen der ersten und zweiten Generation}, doi = {10.25972/OPUS-24311}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-243119}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Zum 01.06.2017 wurde in der Universit{\"a}tsklinik W{\"u}rzburg im Rahmen des 'Antimicrobial Stewardship' in der Herzchirurgie die perioperative Antibiotikaprophylaxe von Cefuroxim auf Cefazolin umgestellt. Diese Studie untersucht insgesamt 1029 Patienten vor und nach der Umstellung hinsichtlich ihrer Raten an Wundinfektionen, nosokomialen Infektionen und Risikofaktoren zur Entwicklung einer postoperativen Wundinfektion. Die Ergebnisse zeigen, dass eine Umstellung der perioperativen Antibiotikaprophylaxe von Cefuroxim, einem Cephalosporin der zweiten Generation, auf Cefazolin, ein Cephalosporin der ersten Generation, zu keinem Anstieg der Wundinfektionen in herzchirurgischen Eingriffen f{\"u}hrt. Insgesamt lag keine signifikante {\"U}berlegenheit eines der beiden Antibiotika vor, weder in Hinblick auf die gesamten Wundinfektionen, die tiefen sternalen Wundinfektionen und die Infektionen der Beinwunde, noch bei nosokomialen Infektionen wie der Pneumonie, dem Harnwegsinfekt oder der Sepsis. Im Patientenkollektiv konnten weiterhin einige unabh{\"a}ngige pr{\"a}-, intra- und postoperative Risikofaktoren ermittelt werden, die zu einer signifikanten Steigerung der Infektionsraten f{\"u}hrten. Auch bei der differenzierten Betrachtung der Risikopatienten zeigte sich kein signifikanter Wirkungsunterschied zwischen den beiden untersuchten Antibiotika. Diese Studie weist mit 1029 Patienten ein zur existierenden Literatur vergleichsweise großes Patientenkollektiv auf. Auch die erhobenen Parameter sind umfangreich gew{\"a}hlt und boten die M{\"o}glichkeit tiefergehender Analysen. Limitiert wird die Studie jedoch durch ihr retrospektives Design mit dem Fehlen eines kontrollierten Follow-Ups. Um die Ergebnisse best{\"a}tigen und bekr{\"a}ftigen zu k{\"o}nnen, m{\"u}sste eine prospektive, randomisierte Studie hieran angeschlossen werden.}, subject = {Antibiotikum}, language = {de} } @phdthesis{Hinderer2021, author = {Hinderer, Sandra}, title = {Charakterisierung der Freisetzung verschiedener Antibiotika aus resorbierbaren anorganischen Knochenersatzmaterialien sowie die Untersuchung des Einflusses auf materialcharakteristische Eigenschaften}, doi = {10.25972/OPUS-23083}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230836}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Synthetische anorganische Knochenersatzmaterialien auf Calcium-Phosphat- und Magnesium-Phosphat-Basis wurden in der hier vorliegenden Dissertation mit verschiedenen handels{\"u}blichen Antibiotika versetzt und deren Freisetzungsverhalten charakterisiert. Zudem wurde der Einfluss des Antibiotikazusatzes auf bestimmte materialcharakteristische Eigenschaften untersucht, hierbei fanden die Quecksilberporosimetrie, die R{\"o}ntgendiffraktometrie und die Rasterelektronenmikroskopie ihre Anwendung. Insbesondere f{\"u}r die Knochenersatzmaterialien auf Calcium-Phosphat-Basis sollte eine klinisch praktikable und demnach m{\"o}glichst einfache Methode etabliert werden, um die Kombination mit einem Antibiotikum durchzuf{\"u}hren. Die Detektion der Antibiotika erfolgte mit Hilfe eines UV/VIS-Spektrophotometers. Zudem wurde f{\"u}r einige ausgew{\"a}hlte Kombinationen aus Antibiotikum und Knochenersatzmaterial durch einen Agardiffusionstest die antibakterielle Wirkung nach der Freisetzung aus dem jeweiligen Tr{\"a}germaterial best{\"a}tigt.}, subject = {Wirkstofffreisetzung}, language = {de} } @phdthesis{Piazza2021, author = {Piazza, Giuseppina}, title = {Evaluation der pr{\"a}station{\"a}ren, station{\"a}ren und poststation{\"a}ren antibiotischen Therapie bei Kindern und Jugendlichen mit parapneumonischen Pleuraerg{\"u}ssen/-empyemen in Deutschland (2010-2018)}, doi = {10.25972/OPUS-24335}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-243351}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Die Dissertation untersucht die vorstation{\"a}re, station{\"a}re und poststation{\"a}re antibiotische Therapie bei 1724 Kindern und Jugendlichen mit parapneumonischen Pleuraerg{\"u}ssen/-empyemen in Deutschland. Der Untersuchungszeitraum war von Oktober 2010 bis Juni 2018. Untersucht wurden jeweils die Wirkstoffauswahl der h{\"a}ufigsten Mono- und Mehrfachtherapien, wie oft die Therapie im station{\"a}ren Verlauf erweitert oder umgestellt wurden, sowie der klinische Verlauf der Patienten.}, subject = {Pleuraempyem}, language = {de} } @phdthesis{Saedtler2021, author = {Saedtler, Marco}, title = {Pharmaceutical formulation strategies for novel antibiotic substances utilizing salt formation and two- and three-dimensional printing techniques}, doi = {10.25972/OPUS-21978}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219784}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Salt formation is a routinely used strategy for poorly water-soluble drugs and traditionally performed with small inorganic counterions. High energy crystal lattices as well as effects on the local pH within the aqueous boundary layer during dissolution drive the increased dissolution rate and apparent solubility. Ionic liquids however, by definition low melting ionic salts with often large organic counterions, combine an increased dissolution rate with solubilization of the drug by the counterion itself. Long lasting supersaturation profiles of increased kinetic solubility were reported for several drugs formulated as ionic liquids increasing their overall bioavailability. Furthermore, aggregation and micellization between highly lipophilic compounds and amphiphilic bile acids was described before, demonstrating the capabilities of the human body itself to utilize solubilization of poorly water-soluble compounds. Development of novel counterions not only tailoring the desired physicochemical properties e.g. dissolution rate of the parent drug but adding - in a best-case scenario synergistic - pharmacological activity has been driven forward in the last years. However, salt formation can only be applied for ionizable i.e. acidic or basic compounds. While co-crystals can be used as a nonionized alternative, their formation is not always successful leading to an urgent need for other formulation strategies. In these lines, development of 2D and 3D printing techniques has been ongoing for the last decades and their pharmaceutical application has been demonstrated. The versatile nature and commercial availability allow a decentralized production further elaborating this technique for a highly flexible and patient-oriented supply with medication. This thesis focuses on the theoretical background and potential application of salt formation in the pharmaceutical development of a drug candidate. The first section presents the current knowledge and state of the art in preparation of low melting ionic liquids i.e. salts and is translated to the in vitro investigation of molecular interaction between the poorly water-soluble drug imatinib and components of the human intestinal fluid in the second section. Development of novel antibiotic counterions and assessment of their potential use in pharmaceutical formulations with fluoroquinolones is described in the last two sections. Chapter I describes the application of low melting ionic liquids in pharmaceutical formulation and details their development in the last two decades from versatile organic solvents in chemical synthesis towards amorphous strategies for drug delivery. The chapter gives a general overview on molecular structure and physicochemical properties of several drug containing ionic liquids and details the mechanisms which attribute to a typically fast dissolution, increased aqueous solubility as well as enhanced permeation which was reported in several publications. Chapter II translates the increased aqueous solubility of drugs by an organic counterion to the human gastrointestinal tract with taurocholate and lecithin as main drivers for the solubilization of highly lipophilic and poorly water-soluble drugs. Investigation of the interaction of imatinib - a poorly water-soluble weak base - with fasted- and fed state simulated intestinal fluids revealed a complex interplay between the components of the intestinal fluid and the drug. Mixed vesicles and micelles were observed in concentration dependent aggregation assays and revealed differences in their size, molecular arrangement as well as composition, depending on the tested drug concentration. Overall, the study outlines the effective interaction of weakly basic drugs with taurocholate and lecithin to minimize recrystallization during intestine passage finally leading to favorable supersaturation profiles. Chapter III focuses on the development of novel antibiotic counterions which potentially move the evolution of ionic liquids from a pharmaceutical salt with tailored physicochemical properties to a synergistic combination of two active pharmaceutical ingredients. The natural occurring anacardic acid derived from the cashew nut shell inspired a series of antibacterial active acidic compounds with increasing alkyl chain length. Their physicochemical properties, antibacterial activity, bacterial biofilm inhibition and cytotoxicity were detailed and in vivo activity in a Galleria mellonella model was assessed. This group of anacardic acid derivatives is synthetically accessible, easily modifiable and yielded two compounds with favorable activity and physicochemical profile for further drug development. Chapter IV outlines the potential application of anacardic acid derivatives in pharmaceutical formulations by salt formation with fluoroquinolone antibiotics as well as novel techniques such as 2D/3D printing for preparation of drug imprinted products. Despite anacardic acid derivatives demonstrated promising physicochemical properties, salt formation with fluoroquinolone antibiotics was not feasible. However, 2D/3D printed samples with anacardic acid derivative alone or in combination with ciprofloxacin demonstrated physical compatibility between drug and matrix as well as antibacterial activity against three S. aureus strains in an agar diffusion assay. Conclusively, drug printing can be applied for the herein tested compounds, but further process development is necessary. In summary, preparation of low melting ionic liquids, salts or co-crystals is an appropriate strategy to increase the aqueous solubility of poorly water-soluble drugs and tailor physicochemical properties. The counterion itself solubilizes the drug and furthermore potentially interferes with the complex micellar environment in the human intestine. However, salt formation as routinely used formulation strategy is not feasible in every case and development of alternative techniques is crucial to hurdle challenges related to unfavorable physicochemical properties. The outlined techniques for 2D/3D drug printing provide versatile production of drug products while extending the design space for novel drug development.}, subject = {L{\"o}slichkeit}, language = {en} }