O peróxido de benzoíla, produto de interação do peróxido de sódio com cloreto de benzoíla, é um poderoso agente antibacteriano de amplo espectro com ação queratolítica, comedolítica, descamativa, antipruriginosa e desengordurante, além de também ser um potente agente oxidante, que reage com materiais orgânicos rompendo as membranas celulares de inúmeros agentes patogênicos. Em virtude de suas características, o peróxido de benzoíla é utilizado como produto de eleição como adjuvante no tratamento de sarnas (dermodicidoses), desqueratinizações, complexo seborréico, piodermites, foliculites superficiais, impetigo e piodermite de dobras. Neste projeto é abordado o desenvolvimento e validação de um método indicador de estabilidade do fármaco peróxido de benzoíla, cujo objetivo é ser utilizado como ferramenta para a identificação e doseamento de maneira precisa e exata dos produtos de degradação desconhecidos formados, a partir de variados ambientes de acondicionamento estressantes, nos quais o medicamento possa ser eventualmente submetido durante o seu prazo de vida de prateleira. O método analítico proposto foi validado conforme os requerimentos vigentes da ANVISA e se baseia na técnica de cromatografia líquida de alta eficiência (CLAE) para doseamento do princípio ativo e seus produtos de degradação, em uma única corrida analítica, o que permite determiná-los simultaneamente, e portanto é adequado para utilização durante o estudo de estabilidade acelerado e de longa duração, além de metodologia indicadora de estabilidade.Durante o estudo de degradação forçada foram geradas uma série de \"picos\" desconhecidos inerentes ao fármaco, especialmente nas condições de aquecimento, hidrólise em meios ácido e alcalino, e fotólise. Entretanto, durante o estudo foram investigados aqueles originados a partir desta última, uma vez a posologia da preparação medicamentosa estudada é via tópica, pois se trata da forma farmacêutica semi-sólida gel. Para avaliação dos produtos de degradação gerados durante a fotólise foi utilizada a cromatografia líquida com detecção por espectrometria de massas, onde o fármaco foi ionizado na forma positiva (+) através da técnica Electrospray ionization (ESI+), a qual permitiu a proposição da estrutura molecular da substância gerada, a partir da provável perda do grupamento alquil ou aldeído, justificando assim a razão massa carga 199,1 u.m.a. / Benzoyl peroxide , the produced by interaction of sodium peroxide with Benzoyl chloride is a powerful antibacterial agent with keratolytic , comedolytic , scaly , antipruritic and degreasing action, as well as being a powerful oxidizing agent that reacts with organic materials disrupting the membrane cell of many pathogens agents . Due to its characteristics, benzoyl peroxide is used as the main choice in the treatment of scabies, seborrhea complex, pyoderma, superficial folliculitis, impetigo and pyoderma folds. This project addresses the development and validation of an indicator stability method for benzoyl peroxide, which is intended to be used as a tool for the identification and accurate and preciously determination of unknown degradation products formed from various stressful environments, in which the API may eventually be submitted during the period of shelf life. The proposed analytical method was validated according to the applicable/current requirements of ANVISA and it is based on the technique of high performance liquid chromatography (HPLC) assay for the active ingredient and its degradation products in a single analytical run, allowing dosing them simultaneously, and thus it is suitable for use during accelerated and long term stability studies and as stability indicating method. During the forced degradation study many unknown \"peaks\" inherent to drug were generate, especially under heating, acid and alkaline hydrolysis, beyond photolysis conditions. However, throughout this study were investigated that obtained from the photolysis, since the sample preparation are applied topically because it is semi - solid dosage gel form. To evaluate the degradation products generated during photolysis were used liquid chromatography with detection by mass spectrometry, where the drug was ionized in the positive (+) form by technical Electrospray ionization (ESI+) technique, which allowed the proposition of the molecular structure substance generated from the probable loss of the alkyl or aldehyde grouping , thus justifying the mass/charge ratio 199.1 amu.

O peróxido de benzoíla, produto de interação do peróxido de sódio com cloreto de benzoíla, é um poderoso agente antibacteriano de amplo espectro com ação queratolítica, comedolítica, descamativa, antipruriginosa e desengordurante, além de também ser um potente agente oxidante, que reage com materiais orgânicos rompendo as membranas celulares de inúmeros agentes patogênicos. Em virtude de suas características, o peróxido de benzoíla é utilizado como produto de eleição como adjuvante no tratamento de sarnas (dermodicidoses), desqueratinizações, complexo seborréico, piodermites, foliculites superficiais, impetigo e piodermite de dobras. Neste projeto é abordado o desenvolvimento e validação de um método indicador de estabilidade do fármaco peróxido de benzoíla, cujo objetivo é ser utilizado como ferramenta para a identificação e doseamento de maneira precisa e exata dos produtos de degradação desconhecidos formados, a partir de variados ambientes de acondicionamento estressantes, nos quais o medicamento possa ser eventualmente submetido durante o seu prazo de vida de prateleira. O método analítico proposto foi validado conforme os requerimentos vigentes da ANVISA e se baseia na técnica de cromatografia líquida de alta eficiência (CLAE) para doseamento do princípio ativo e seus produtos de degradação, em uma única corrida analítica, o que permite determiná-los simultaneamente, e portanto é adequado para utilização durante o estudo de estabilidade acelerado e de longa duração, além de metodologia indicadora de estabilidade.Durante o estudo de degradação forçada foram geradas uma série de \"picos\" desconhecidos inerentes ao fármaco, especialmente nas condições de aquecimento, hidrólise em meios ácido e alcalino, e fotólise. Entretanto, durante o estudo foram investigados aqueles originados a partir desta última, uma vez a posologia da preparação medicamentosa estudada é via tópica, pois se trata da forma farmacêutica semi-sólida gel. Para avaliação dos produtos de degradação gerados durante a fotólise foi utilizada a cromatografia líquida com detecção por espectrometria de massas, onde o fármaco foi ionizado na forma positiva (+) através da técnica Electrospray ionization (ESI+), a qual permitiu a proposição da estrutura molecular da substância gerada, a partir da provável perda do grupamento alquil ou aldeído, justificando assim a razão massa carga 199,1 u.m.a. / Benzoyl peroxide , the produced by interaction of sodium peroxide with Benzoyl chloride is a powerful antibacterial agent with keratolytic , comedolytic , scaly , antipruritic and degreasing action, as well as being a powerful oxidizing agent that reacts with organic materials disrupting the membrane cell of many pathogens agents . Due to its characteristics, benzoyl peroxide is used as the main choice in the treatment of scabies, seborrhea complex, pyoderma, superficial folliculitis, impetigo and pyoderma folds. This project addresses the development and validation of an indicator stability method for benzoyl peroxide, which is intended to be used as a tool for the identification and accurate and preciously determination of unknown degradation products formed from various stressful environments, in which the API may eventually be submitted during the period of shelf life. The proposed analytical method was validated according to the applicable/current requirements of ANVISA and it is based on the technique of high performance liquid chromatography (HPLC) assay for the active ingredient and its degradation products in a single analytical run, allowing dosing them simultaneously, and thus it is suitable for use during accelerated and long term stability studies and as stability indicating method. During the forced degradation study many unknown \"peaks\" inherent to drug were generate, especially under heating, acid and alkaline hydrolysis, beyond photolysis conditions. However, throughout this study were investigated that obtained from the photolysis, since the sample preparation are applied topically because it is semi - solid dosage gel form. To evaluate the degradation products generated during photolysis were used liquid chromatography with detection by mass spectrometry, where the drug was ionized in the positive (+) form by technical Electrospray ionization (ESI+) technique, which allowed the proposition of the molecular structure substance generated from the probable loss of the alkyl or aldehyde grouping , thus justifying the mass/charge ratio 199.1 amu.

Das Ziel der vorliegenden Arbeit ist die bessere Verarbeitung von Polyanilin (PANI), da dies bisher ein großer Nachteil unter leitfähigen Polymeren war. Dazu wird ein sperriges Tensid und Dotand, Dodecylbenzensulfonsäure (DBSA) verwendet. Zur Synthese der PANI kommen zwei verschiedene Methoden zur Anwendung, die in dieser Dissertation in zwei Kapiteln beschrieben werden. Im ersten Teil wurden in einem kleinen Reaktionsvolumen (250 mL) PANI-DBSA-Suspensionen synthetisiert, wobei mit einem binären Gemisch aus 2-Propanol und Wasser als Lösungsmittel gearbeitet wird um die Löslichkeit zu unterstützen. Die micellenunterstützte Synthese produziert grüne Dispersionen, welche nach länger als einem Jahr noch keine sichtbare Ausscheidung zeigen. Eine detaillierte spectroelektrochemische Untersuchung der PANI-DBSA-Nanokolloide wurde durchgeführt und gibt eine bessere Erklärung der Charge-Transfer-Prozesse zwischen PANI-Kolloiden und Elektrodenoberfläche. In einem alkalischen Medium ist das UV-Vis-Spektrum von der Beweglichkeit der Anionen und von einem elektrokinetischen Phänomen abhängig. Um den „metal-to-insulator”-Übergang zwischen PANI-Kolloiden, welcher durch pH-Wert-Änderung des Mediums geschehen kann, zu zeigen, wurden UV-Vis- und pre-resonanz-Raman-Spektroskopie verwendet. Im zweiten Teil der Dissertation wird zur Polymerisation von Anilin sowie seinen Copolymeren mit o-Toluidin eine neue Technik der Polymerisation beschrieben, welche durch inverse Emulsion erfolgt. Diese benutzt Benzoylperoxid, ein ungewöhnlicheres organisches Oxidationsmittel. Die erhaltenen PANI sind in gebräuchlichen organischen Lösungsmitteln, wie in Chloroform, vollständig löslich. Mit einer klar-transparenten, grünen Lösung von PANI können metallische Oberflächen oder Glas leicht tropfenbeschichtet werden. Zyklische Voltammetrie und spektroelektrochemische Verfahren kamen zum Einsatz, um die Elektroaktivität, das UV-Vis-Verhalten und die „metal-to-insulator”-Übergänge der chemisch synthetisierten PANI als Funktion des verwendeten Elektrodenpotentials zu untersuchen. Die elektrische Leitfähigkeit der Materialien ist relativ hoch (R = 10 ). SEM-Untersuchungen zeigen, dass die Menge des zugesetzten DBSA die Morphologie des Polymers stark beeinflusst. Aus in situ UV-Vis-spektroskopischen Messungen lässt sich eine gute elektrochromische Reversibilität des Polymers erkennen. DBSA kann Poly(o-toluidin) (POT) effektiv dotieren, auch wenn von der Methylgruppe eine sterische Hinderung ausgeht. Die spektroskopischen Untersuchungen, wie UV-Vis, FT-IR, Raman-Spektroskopie und zyklische Voltammetrie, zeigen deutlich, dass wirkliche Copolymere gebildet werden und die Möglichkeit von Kompositen nicht in Betracht kommt. Das entstandene Poly(anilin-co-o-toluidin) (PAT) ist in schwach polaren Lösungsmitteln wie Chloroform löslich. Wie erwartet, sind die elektrischen Leitfähigkeiten der Copolymere viel kleiner als die Leitfähigkeit von PANI-DBSA.

Content: Chamois leathers are basically oil tanned leathers, usually requires 10 to 15 days to process from raw skins. In chamois making, air oxidation plays a major role, free radicals initiate the oxidation process in oil, which oxidizes the double bond of the fatty acid and then the oxidized oil interacts with collagen to stabilize the skin by coating the fibers (Fig 1). In the present study an attempt has been made to reduce the time for chamois leather processing. A common oxidizing agent (Benzoyl peroxide (BPO) was utilized to enhance the oxidation of oil and reduce the time duration. It has been observed that the oxidation of oil in the presence of benzoyl peroxide has significantly reduced the duration of process from 15 to 4 days. Strength properties such as tensile, percentage elongation and organoleptic properties were found to be on par with control leather. The water absorption values of the experimental leathers improved by 1-26 %, compared with control leather. Microscopic analysis (SEM) was employed to study the fiber alignment of the chamois leathers. Take-Away: 1. Time reduction in chamois leather processing 2. Inexpensive and common oxidising agents were employed 3.Improved water absorption of chamois leather

Benzoyl peroxide (BPO) is a common bleaching agent used in wheat flour. Due to its ability to damage existing nutrients in food and potential adverse effect to health, BPO have been strictly banned as a food additive in several countries and regions, such as China and Europe. However, the United States specifies that BPO is generally recognized as safe (GRAS). So, the WHO/FAO created a Codex Alimentarius Commission (CAC) to regulate the international BPO usage standard. According to the CAC, it is restricted at 75 mg/kg or parts per million (ppm). BPO is very unstable and easily converts to benzoic acid (BA), which places the analytical challenge for accurate BPO quantification. The objective of this study is to develop a reliable method for BPO quantification in flour. Raman spectroscopy was first explored to detect BPO and BA on an aluminum foil slide. The result showed BPO and BA produced distinct Raman peaks that can be discriminated against. However, the sensitivity was not satisfactory to reach the regulation limit. To improve sensitivity, surface-enhanced Raman spectroscopy (SERS) was applied using silver nanoparticles as the substrate. Although the signals did enhance significantly using SERS, the characteristic peaks of BPO disappeared as BPO converted to BA during the sample preparation. We then went back to Raman spectroscopy but focused on optimizing the sample preparation to enhance the signal intensity. Using a hydrophobic surface (i.e., parafilm) which can hold the droplet and minimize the spread, the Raman signal was enhanced significantly after repeating multiple droplets on the same surface. A standard curve was created for BPO from 25 ppm to 250 ppm and for BA from 250 ppm to 1000 ppm, respectively. To detect BPO in wheat flour, we applied a more advanced Raman imaging instrument and focused on the analysis of Raman maps instead of spectra for the analysis of effect flour matrix to BPO extraction and detection. We firstly tried an in situ method, which scanned the pellet of flour spiked with different amounts of BPO without extraction. However, we could not detect BPO at 0.1% or lower in flour samples. We then tried an extraction method using acetonitrile as the solvent, which showed a lower detection limit compared to the in situ method. However, this extraction method yielded inconsistent results for BPO that is under 0.05% in flour. The extraction method developed was further improved with an evaporating step and a C18 solid phase extraction (SPE) spin column. This improved the extraction efficacy and provided a roughly 60% recovery percentage for detecting BPO in wheat flour without decomposing into BA. In conclusion, we developed a simple sample preparation protocol coupled with Raman spectroscopy to quantify BPO in flour without converting to BA, which would meet the regulation requirement. This method also shortened the experiment time including both sample preparation and detection time compared to current methods.

Das Ziel der vorliegenden Arbeit ist die bessere Verarbeitung von Polyanilin (PANI), da dies bisher ein großer Nachteil unter leitfähigen Polymeren war. Dazu wird ein sperriges Tensid und Dotand, Dodecylbenzensulfonsäure (DBSA) verwendet. Zur Synthese der PANI kommen zwei verschiedene Methoden zur Anwendung, die in dieser Dissertation in zwei Kapiteln beschrieben werden. Im ersten Teil wurden in einem kleinen Reaktionsvolumen (250 mL) PANI-DBSA-Suspensionen synthetisiert, wobei mit einem binären Gemisch aus 2-Propanol und Wasser als Lösungsmittel gearbeitet wird um die Löslichkeit zu unterstützen. Die micellenunterstützte Synthese produziert grüne Dispersionen, welche nach länger als einem Jahr noch keine sichtbare Ausscheidung zeigen. Eine detaillierte spectroelektrochemische Untersuchung der PANI-DBSA-Nanokolloide wurde durchgeführt und gibt eine bessere Erklärung der Charge-Transfer-Prozesse zwischen PANI-Kolloiden und Elektrodenoberfläche. In einem alkalischen Medium ist das UV-Vis-Spektrum von der Beweglichkeit der Anionen und von einem elektrokinetischen Phänomen abhängig. Um den „metal-to-insulator”-Übergang zwischen PANI-Kolloiden, welcher durch pH-Wert-Änderung des Mediums geschehen kann, zu zeigen, wurden UV-Vis- und pre-resonanz-Raman-Spektroskopie verwendet. Im zweiten Teil der Dissertation wird zur Polymerisation von Anilin sowie seinen Copolymeren mit o-Toluidin eine neue Technik der Polymerisation beschrieben, welche durch inverse Emulsion erfolgt. Diese benutzt Benzoylperoxid, ein ungewöhnlicheres organisches Oxidationsmittel. Die erhaltenen PANI sind in gebräuchlichen organischen Lösungsmitteln, wie in Chloroform, vollständig löslich. Mit einer klar-transparenten, grünen Lösung von PANI können metallische Oberflächen oder Glas leicht tropfenbeschichtet werden. Zyklische Voltammetrie und spektroelektrochemische Verfahren kamen zum Einsatz, um die Elektroaktivität, das UV-Vis-Verhalten und die „metal-to-insulator”-Übergänge der chemisch synthetisierten PANI als Funktion des verwendeten Elektrodenpotentials zu untersuchen. Die elektrische Leitfähigkeit der Materialien ist relativ hoch (R = 10 ). SEM-Untersuchungen zeigen, dass die Menge des zugesetzten DBSA die Morphologie des Polymers stark beeinflusst. Aus in situ UV-Vis-spektroskopischen Messungen lässt sich eine gute elektrochromische Reversibilität des Polymers erkennen. DBSA kann Poly(o-toluidin) (POT) effektiv dotieren, auch wenn von der Methylgruppe eine sterische Hinderung ausgeht. Die spektroskopischen Untersuchungen, wie UV-Vis, FT-IR, Raman-Spektroskopie und zyklische Voltammetrie, zeigen deutlich, dass wirkliche Copolymere gebildet werden und die Möglichkeit von Kompositen nicht in Betracht kommt. Das entstandene Poly(anilin-co-o-toluidin) (PAT) ist in schwach polaren Lösungsmitteln wie Chloroform löslich. Wie erwartet, sind die elektrischen Leitfähigkeiten der Copolymere viel kleiner als die Leitfähigkeit von PANI-DBSA.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Veronika Ackermannová Supervisor: prof. Radomír Hrdina, MD, CSc. Title of diploma thesis: Topic and systemic treatment of acne vulgaris Acne vulgaris is a skin disease affecting the hair follicles and sebaceous glands. The disease manifests itself by increased sebum production, non-inflammatory (comedones) and inflammatory lesions (papules, pustules, nodules, cysts). It occurs predominantly in adolescents, but may persist into adulthood. It is a multifactorial disease, which is caused by several factors (internal and external stimuli). The major pathogenetic factors include increased sebum production, hyperkeratosis, P. acnes colonization and inflammation present. First, it is necessary to diagnose the type of acne in order to choose the right and effective therapy, because there is not only one type of acne. There are many types and variants of acne, and although they show similar symptoms (affecting the follicles of sebaceous glands), their cause often differs. There is no uniform classification system for acne vulgaris and it varies between authors. Some authors classify acne vulgaris according to severity into mild, moderate and severe, others into comedonic, papulopustular, nodulocystic...

The polymerization of methyl methacrylate (MMA) was investigated in this dissertation. Selected kinetic models from the literature were reviewed, and two new, generalized models of diffusion-limited effects (gel- and glass effects), derived from the current models were proposed and tested for bulk and solution polymerization of MMA in batch and semi-batch reactors, under isothermal and non-isothermal conditions. The newly proposed models include the capability of modeling termination by combination, radical transfer to monomer and depropagation reaction. The new and previous models were compared with experimental data of bulk and solution polymerizations of MMA, under a selection of non-steady state processes conditions (initiator and monomer feed, step changes in temperature) and compositions (initiator and chain transfer agents, regarding both type and dosages). The particular case of a non-isothermal bulk polymerization was also investigated. A simulation program (Reactormodel) was developed in Matlab, and its algorithm is provided. / Sem resumo.