Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents a study of the use of sugarcane bagasse as an alternative source of cellulose, for obtaining cellulose triacetate (CTA) and consequently production of membranes for use in controlled release system (CRS) of the drugs naproxen (water insoluble) and doxycycline (water soluble). The sugarcane bagasse was delignified from three successive reflux of a mixture 80/20 (v/v) nitric acid concentrated and ethanol, subsequently treated in NaOH solution. From the analysis of Klason Lignin, noted that in delignified bagasse (DB) there was a reduction in lignin content of 98% compared with gross bagasse. CTA produced presented degree of substitution (DS) 2.80 ± 0.09, what classifies as cellulose triacetate (CTA). The formulations used, CTA/dichloromethane/drug and CTA/dichloromethane/water/drug led to the production of symmetric and asymmetric I membranes, respectively. The formulation with the system solvent dioxane/acetone resulted in asymmetric II membranes with pores in thickness and dense surface, morphologies observed from the analysis of scanning electron microscopy (SEM). The results of the thermal analysis showed that there are interactions between drugs and the CTA. The polymeric matrices showed Swelling index (Si) approximately 12%, a result that will influence on the release kinetics of drugs. The content of naproxen released was 8, 50 and 25% from symmetric, asymmetric I and asymmetric II membranes, respectively. Doxycycline presented release content 14% in experiments with symmetric membranes and 80% with asymmetric I membranes. The study of CRS of drugs showed that membrane morphology has great influence on drugs desorption and the release occurs predominantly by diffusion. / Esse trabalho apresenta um estudo da utilização de bagaço de cana de açúcar como fonte alternativa de celulose, para a obtenção de triacetato de celulose (TAC) e consequentemente produção de membranas para o uso em sistema de liberação controlada (SLC) dos fármacos naproxeno (lipossolúvel) e doxiciclina (hidrossolúvel). O bagaço de cana de açúcar foi deslignificado a partir de três refluxos sucessivos de uma mistura 20/80 (v/v) de ácido nítrico concentrado e etanol hidratado, e posteriormente tratado em solução NaOH. A partir da análise de Lignina Klason, observou se que no bagaço deslignificado (BD) houve uma redução no teor de lignina de 98 % em relação ao bagaço bruto. O TAC produzido apresentou grau de substituição 2,80 ± 0,09, classificando-o como triacetato de celulose (TAC). As formulações utilizadas, TAC/diclorometano/ fármaco e TAC/diclorometano/água/ fármaco levaram à produção de membranas simétricas e assimétricas I, respectivamente. A formulação com o sistema solvente dioxano/acetona resultou em membranas assimétricas II com poros na espessura e superfície mais densa, morfologias observadas a partir das análises de Microscopia Eletrônica de Varredura (MEV). Os resultados da análise térmica mostraram que há interações entre os fármacos e o TAC. As matrizes poliméricas apresentaram Índice de Intumescimento (Ii) de aproximadamente 12 %, resultado que influenciou na cinética de liberação das drogas. O teor do naproxeno liberado foi 8, 50 e 25 % a partir das membranas simétricas, assimétricas I e assimétricas II, respectivamente. A doxiciclina apresentou teor de liberação de 14 % nos experimentos com as membranas simétricas e 80 % com as assimétricas I. O estudo do SLC das drogas mostrou que a morfologia das membranas exerce grande influência na dessorção dos fármacos e a liberação ocorre predominantemente por difusão. / Mestre em Química

What is known and objective: Although non-steroidal anti-inflammatory drugs (NSAIDs) have been studied in randomized, controlled trials and meta-analyses in an effort to determine their cardiovascular (CV) risks, no consensus has been reached. These studies continue to raise questions, including whether cyclooxygenase-2 (COX-2) selectivity plays a role in conferring CV risk. We performed a meta-analysis of current literature to determine whether COX-2 selectivity leads to an increased CV risk. Methods: We utilized randomized, controlled trials and prospective cohort studies. We selected eight NSAIDs based on popularity and COX selectivity and conducted a search of the MEDLINE, EMBASE, and Cochrane databases. Primary endpoints included any myocardial infarction (MI), any stroke, CV death, and a combination of all three (composite CV outcomes). Twenty-six studies were found that met inclusion and exclusion criteria. Comparisons were made between all included drugs, against placebo, and against non-selective NSAIDs (nsNSAIDs). Drugs were also compared against COX-2 selective inhibitors (COXIBs) with and without inclusion of rofecoxib. Results and discussion: Incidence of MI was increased by rofecoxib in all comparison categories [all NSAIDs (OR: 1·811, 95% CI: 1·379–2·378), placebo (OR: 1·655: 95% CI: 1·029–2·661), nsNSAIDs (OR: 2·155, 95% CI: 1·146–4·053), and COXIBs (OR: 1·800, 95% CI: 1·217–2·662)], but was decreased by celecoxib and naproxen in the COXIB comparison [(OR: 0·583, 95% CI: 0·396–0·857) and (OR: 0·609, 95% CI: 0·375–0·989, respectively]. Incidence of stroke was increased by rofecoxib in comparisons with all NSAIDs and other COXIBs [(OR: 1·488, 95% CI: 1·027–2·155) and (OR: 1·933, 95% CI: 1·052–3·549), respectively]. Incidence of stroke was decreased by celecoxib when compared with all NSAIDs, nsNSAIDs, and COXIBs [(OR: 0·603, 95% CI: 0·410–0·887), (OR: 0·517, 95% CI: 0·287–0·929), and (OR: 0·509, 95% CI: 0·280–0·925), respectively]. No NSAID reached statistical significance in regard to CV death. Incidence of the composite endpoint was increased by rofecoxib when compared against all NSAIDs, placebo, and other COXIBs [(OR: 1·612, 95% CI: 1·313–1·981), (OR: 1·572, 95% CI: 1·123–2·201) and (OR: 1·838, 95% CI: 1·323–2·554), respectively]. Incidence of composite endpoint was decreased by celecoxib in the all NSAIDs and COXIBs comparisons [(OR: 0·805, 95% CI: 0·658–0·986) and (OR: 0·557, 95% CI: 0.404–0.767), respectively]. When rofecoxib was removed from the COXIBs group, no difference was found with any comparison, suggesting rofecoxib skewed the data. What is new and conclusion: This instead of the meta-analysis suggests that COX-2 selectivity may not play a role in the CV risk of NSAIDs. Rofecoxib was the only drug to demonstrate harm and skewed the data of the COX-2 selective group.

The theoretical part shortly describes chirality with focus on chiral pharmaceuticals. The processes of their absorption, distribution, metabolism and elimination in human body are discussed. These points are very important to understand possible fate of chiral drugs in the environment as there is only little data concerning their environmental behaviour. The occurrence and enantioselective toxicity of chiral drugs is also discussed here. One of the chapters describes non-steroidal anti-inflammatory drugs, as they are analyzed in the wastewater in the experimental part, and their occurrence in the environment. The experimental part describes optimization of the enantioselective HPLC method using Chiralpak AD as column for ibuprofen and ketoprofen. Reproducible separation of enantiomers wasn’t achieved for naproxen. Optimized methods were then applied for analysis of samples from municipal wastewater treatment plant in Brno-Modřice.

What is known and objective: Although non-steroidal anti-inflammatory drugs (NSAIDs) have been studied in randomized, controlled trials and meta-analyses in an effort to determine their cardiovascular (CV) risks, no consensus has been reached. These studies continue to raise questions, including whether cyclooxygenase-2 (COX-2) selectivity plays a role in conferring CV risk. We performed a meta-analysis of current literature to determine whether COX-2 selectivity leads to an increased CV risk. Methods: We utilized randomized, controlled trials and prospective cohort studies. We selected eight NSAIDs based on popularity and COX selectivity and conducted a search of the MEDLINE, EMBASE, and Cochrane databases. Primary endpoints included any myocardial infarction (MI), any stroke, CV death, and a combination of all three (composite CV outcomes). Twenty-six studies were found that met inclusion and exclusion criteria. Comparisons were made between all included drugs, against placebo, and against non-selective NSAIDs (nsNSAIDs). Drugs were also compared against COX-2 selective inhibitors (COXIBs) with and without inclusion of rofecoxib. Results and discussion: Incidence of MI was increased by rofecoxib in all comparison categories [all NSAIDs (OR: 1·811, 95% CI: 1·379-2·378), placebo (OR: 1·655: 95% CI: 1·029-2·661), nsNSAIDs (OR: 2·155, 95% CI: 1·146-4·053), and COXIBs (OR: 1·800, 95% CI: 1·217-2·662)], but was decreased by celecoxib and naproxen in the COXIB comparison [(OR: 0·583, 95% CI: 0·396-0·857) and (OR: 0·609, 95% CI: 0·375-0·989, respectively]. Incidence of stroke was increased by rofecoxib in comparisons with all NSAIDs and other COXIBs [(OR: 1·488, 95% CI: 1·027-2·155) and (OR: 1·933, 95% CI: 1·052-3·549), respectively]. Incidence of stroke was decreased by celecoxib when compared with all NSAIDs, nsNSAIDs, and COXIBs [(OR: 0·603, 95% CI: 0·410-0·887), (OR: 0·517, 95% CI: 0·287-0·929), and (OR: 0·509, 95% CI: 0·280-0·925), respectively]. No NSAID reached statistical significance in regard to CV death. Incidence of the composite endpoint was increased by rofecoxib when compared against all NSAIDs, placebo, and other COXIBs [(OR: 1·612, 95% CI: 1·313-1·981), (OR: 1·572, 95% CI: 1·123-2·201) and (OR: 1·838, 95% CI: 1·323-2·554), respectively]. Incidence of composite endpoint was decreased by celecoxib in the all NSAIDs and COXIBs comparisons [(OR: 0·805, 95% CI: 0·658-0·986) and (OR: 0·557, 95% CI: 0.404-0.767), respectively]. When rofecoxib was removed from the COXIBs group, no difference was found with any comparison, suggesting rofecoxib skewed the data. What is new and conclusion: This instead of the meta-analysis suggests that COX-2 selectivity may not play a role in the CV risk of NSAIDs. Rofecoxib was the only drug to demonstrate harm and skewed the data of the COX-2 selective group.

Functional Dendritic Structures from Bile Acids: Supramolelcular Hosts, Light Harvesters and Drug Carriers Chapter 1. An Overview of Functional Dendrimers. Dendrimers are welldefined, hyperbranched macromolecules that are prepared by highly controlled iterative methodologies. The ability to modulate the size, molecular weight, chemical functionalities and the position and number of functional groups in dendrimers make them promising candidates for a wide variety of applications. In this chapter, three areas 1) hostguest chemistry 2) light harvesting and 3) drug delivery, where dendrimers are increasingly finding applications, are discussed with selected examples. Chapter 2. Hydroxyl Terminated Dendritic Oligomers from Bile Acids: Synthesis and Properties. Bile acids are excellent building blocks for dendritic construction because of their many interesting features. They are readily available, chiral, facial amphiphiles with complementary functionalities. Moreover, due to the large size of the bile acid units, a dendritic structure consisting of only a few such repeat units can have an extended structure with multiple functionalizable groups. (figure 1) The high reactivity of the chloroacetyl group has been exploited for the synthesis of bile acid based first and second-generation dendrons with glycolate linkers and multiple hydroxyl groups. The synthesis involves only a few steps and avoids the use of protecting groups for the terminal hydroxyl groups. The synthesis of a bile acid tetramer is shown here as an example (Figure 1). Carboxyl protected cholic acid was reacted with chloroacetylchloride to generate the trischloroacetylated derivative. This compound on reaction with excess of sodium cholate generated the tetramer with nine hydroxyl groups via displacement of the chlorides. In order to synthesize higher generation dendritic structures, perchloroacetylated firstgeneration dendrons were first synthesized. These were subsequently reacted with excess of sodium deoxcholate to generated secondgeneration dendrons with multiple hydroxyl groups (Figure 2). All the compounds were characterized by H NMR, C NMR, IR, ESIMS/MALDI-TOF, HPLC and elemental analysis(wherever possible) Figure 2. Structure of tridecamer. These dendritic structures with facially amphiphilic bile acid backbones on the periphery were able to solubilize cresol red, a hydrophilic dye, in a nonpolar solvent, thus exhibiting reverse micellar characteristics. Chapter 3. Multiple Naproxen Appended Bile Acid Dendrimers as Light Harvesters and Drug Carriers. Part I. Synthesis and Characterization. Using the same synthetic strategy as in Chapter 2, bile acid based dendritic structures appended with multiple bioactive (S)naproxens were generated as potential drug carriers. The construction of these dendrimers was accomplished using per(chloroacetylated) bile acid dendrons and conveniently displacing all the chlorides with naproxen units. Since naproxen is photoactive with a high fluorescence quantum Figure 3. Structures of secondgeneration dendrimers and a monomer with multiple naproxens. yield, the photophysical properties of these multichromophoric dendrimers could be further explored (Figure 3). By functionalizing the carboxyl group on the side chain with an anthracenyl moiety the energy transfer properties of these dendrimers could be studied. In this section the synthesis of first and secondgeneration dendritic structures with multiple naproxen units at the periphery and benzyl/anthracenyl moiety on the side chain are described (Figure 3). Model compounds using monomeric bile acid units were synthesized for comparison with the dendritic structures. All the compounds were characterized by H NMR, C NMR, IR, ESIMS/MALDITOF, HPLC and elemental analysis (wherever possible). Part II: Absorption, Fluorescence and Intramolelcular Energy Tranfer Studies. Absorption studies showed that the molar extinction coefficients increase linearly with increasing number of naproxen units and the absorption spectra of anthracenyl moiety remain unchanged in all the dendritic systems. These indicated the absence of ground state interaction between the chromophores. In the 275-290 nm absorption region, the molar extinction coefficient of naproxen is much greater than that of the 9-anthracenylmethyl chromophore. Hence excitation in this region would mainly excite the naphthalene chromophore. Upon excitation at 275 nm, there was predominant emission from the anthracenyl moiety in the dendritic structures (containing both chromophores) and the fluorescence intensity increased with increasing number of naproxens(Figure4). This indicated that the dendrimers act as efficient light harvesters with energy transfer from naproxen to anthracene (intramolecular nature of the energy transfer was confirmed through control experiments). (Figure 4: Refer PDF File) The fluorescence and energy-transfer properties were further investigated by time-resolved fluorescence spectroscopy. The presence of fast decay component(s) in the naproxen decay in dendritic structures (containing both chromophores) indicates that its fluorescence is quenched in the presence of anthracene due to energy transfer ((λex 275 nm, λem 350 nm (Figure 5). This was further confirmed by monitoring the fluorescence of the sensitized anthracenyl chromophore (λex 275 nm, λem 436 nm) which exhibited a fast rise comparable to he quenched naproxen lifetime(s). The efficiency of energy transfer was estimated by donor quenching by both steadystate and timeresolved techniques. The dendritic structures exhibited high energy transfer efficiencies (~ 70 – 90 %) with the net efficiency decreasing from the first to second-generation. Part III. In vitro Study of Hydrolysis of Naproxen Appended Bile Acid Prodrugs by Chemical and Enzymatic Methods. The naproxen appended bile acid dendrimers consist of hydrolyzable ester and glycolate linkers. Hence the chemical stability and enzymatic degradation with possible release of naproxen was studied. Two compounds, monomer appended with two naproxens and trimer with four naproxens have been used for the initial investigations (Figure 6). The compounds were found to be highly stable towards chemical hydrolysis and did not show any hydrolysis in phosphate buffer, pH = 7.4 even after 7 days. Since the compounds were not soluble in water, Arabic gum and TritonX were used for emulsification. Figure 6. Structures of monomer and trimer. (Refer PDF File) The enzymatic hydrolysis of the compounds was then studied using Candida Rugosa Lipase. In both cases, there was slow hydrolysis of the substrate and intermediates were formed (with release of free naproxen) which were detected by HPLC (reverse phase column with a UV detector). The trimer underwent much slower hydrolysis compared to the monomer. The intermediates were characterized by absorption and mass (ESIMSQTOF) spectrometry.

Self-emulsifying systems are mixtures of oils and surfactants, ideally isotropic, sometimes including cosolvents, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastrointestinal tract. The process of self-emulsification has remained the center of attraction for most researchers. Controlled hydration of self-emulsifying systems shows formation of an intermediate gel phase which upon rupture forms an emulsion. Current work was undertaken to understand and explore the microstructural properties of intermediate gel phase which are believed to influence the performance (droplet size) of the final formulation. The effect of additives on microstructural properties of intermediate gel phase has also been investigated. Microstructural elucidation of hydrated samples of intermediate regimes was done by using techniques such as small angle X-ray scattering, differential scanning calorimetry and rheology. Samples from intermediate regimes showed formation of local lamellar structure which swelled with hydration. In the present work, the effect of addition of salt form of naproxen (sodium and potassium) and naproxen (base) on microstructural properties of intermediate regimes was investigated. Systems containing naproxen salts formed larger droplets whereas naproxen base formed smaller ones. Microstructural properties of intermediate lamellar structures were well correlated with performance of the final formulation. The current studies indicate that by controlling the properties of intermediate regimes optimized formulations with desired performance can be tailor-made.