515 resultados para Pharmaceuticals
Resumo:
The medicalisation of life problems has been occurring for well over a century and has increased over the past 30 years, with the engines of medicalisation shifting to biotechnology, managed care, and consumers. This paper examines one strand of medicalisation during the last century: direct-to-consumer advertising (DTCA) of pharmaceuticals. In particular, it examines the roles that physicians and the Food and Drug Administration (FDA) have played in regulating DTCA in the US. Two advertising exemplars, the late 19 century Lydia E. Pinkham's Vegetable Compound (for 'women's complaints') and contemporary Levitra (for erectile dysfunction) are used to examine the parallels between the patent medicine era and the DTCA era. DTCA re-establishes the direct and independent relationship between drug companies and consumers that existed in the late 19 century, encouraging self-diagnosis and requests for specific drugs. The extravagant claims of Lydia Pinkham's day are constrained by laws, but modern-day advertising is more subtle and sophisticated. DTCA has facilitated the impact of the pharmaceutical industry and consumers in becoming more important forces in medicalisation. © 2008 The Authors.
Resumo:
This chapter explores how the EU is a largely overlooked exporter of normative power through its facilitation and use of clinical trials data produced abroad for the marketing of safe pharmaceuticals at home; a move that helps to foster the growing resort to pharmaceuticals as a fix for public health problems. This is made possible by the EU’s (de)selection of international ethical frameworks in preference to the international technical standards it co-authors with other global regulators. Clinical trials abroad underscore how ethics are contingent and revisable in light of market needs, producing weak protections for the vulnerable subjects of EU law. I argue that these components and effects of the regime are ultimately about that which undergirds, shapes and directs regulatory design. That is, I point to the use, infiltration, perpetuation and extension of market-oriented ideas, values and rationalities into formally non-market domains like biomedical knowledge production and public health. I explain how these are central to efforts at producing and legitimating the EU, its related imagined socio-political order based on a more innovative, profitable and competitive pharmaceutical sector in order to foster economic growth, jobs and prosperity, and with them the project of European integration. ‘Bioethics as risk’ is highlighted as a way to reshape and redirect the regulatory regime in ways that are more consistent with the spirit and letter of the ethical standards (and through them the human rights) the EU claims to uphold.
Resumo:
Background: Primary results from the phase 3 ALSYMPCA trial showed that radium-223 dichloride (radium-223), a targeted α-emitter, improved overall survival compared with placebo and was well tolerated in patients with castration-resistant prostate cancer and symptomatic bone metastases. We did a prespecified subgroup analysis from ALSYMPCA to assess the effect of previous docetaxel use on the efficacy and safety of radium-223.
Methods: In the phase 3, randomised, double-blind ALSYMPCA trial, patients with symptomatic castration-resistant prostate cancer, at least two symptomatic bone metastases, no known visceral metastases, and who were receiving best standard of care were randomly assigned (2:1) via an interactive voice response system to receive six injections of radium-223 (50 kBq/kg intravenously) or matching placebo, with one injection given every 4 weeks. Patients had either received previous docetaxel treatment or were unsuitable for or declined docetaxel; previous docetaxel use (yes or no) was a trial stratification factor. We investigated the effect of previous docetaxel use on radium-223 treatment for the primary endpoint of overall survival, the main secondary efficacy endpoints, and safety. Efficacy analyses were done for the intention-to-treat population; safety analyses were done for the safety population. The trial has been completed and is registered with ClinicalTrials.gov, number NCT00699751.
Findings: Randomisation took place between June 12, 2008, and Feb 1, 2011. 526 (57%) of 921 randomly assigned patients had received previous docetaxel treatment (352 in the radium-223 group and 174 in the placebo group) and 395 (43%) had not (262 in the radium-223 group and 133 in the placebo group). Radium-223 prolonged median overall survival compared with placebo, irrespective of previous docetaxel use (previous docetaxel use, hazard ratio [HR] 0·70, 95% CI 0·56-0·88; p=0·002; no previous docetaxel use, HR 0·69, 0·52-0·92; p=0·01). The benefit of radium-223 compared with placebo was seen in both docetaxel subgroups for most main secondary efficacy endpoints; risk for time to time to first symptomatic skeletal event was reduced with radium-223 versus placebo in patients with previous docetaxel use, but the difference was not significant in those with no previous docetaxel use. 322 (62%) of 518 patients previously treated with docetaxel had grade 3-4 adverse events, compared with 205 (54%) of 383 patients without docetaxel. Patients who had previously been treated with docetaxel had a higher incidence of grade 3-4 thrombocytopenia with radium-223 than with placebo (31 [9%] of 347 patients vs five [3%] of 171 patients), whereas the incidence was similar between treatment groups among patients with no previous docetaxel use (seven [3%] of 253 patients vs one [1%] of 130 patients). The incidences of grade 3-4 anaemia and neutropenia were similar between the radium-223 and placebo groups within both docetaxel subgroups.
Interpretation: Radium-223 is effective and well tolerated in patients with castration-resistant prostate cancer and symptomatic bone metastases, irrespective of previous docetaxel use.
Funding: Algeta ASA and Bayer HealthCare Pharmaceuticals.
Resumo:
Chronic infection with Pseudomonas aeruginosa is associated with poor outcomes in patients with cystic fibrosis (CF). It leads to a reduced quality of life, acceleration of the decline in lung function, and increased frequency and severity of pulmonary exacerbations. Tobramycin, administered by inhalation as a long-term therapy, decreases bacterial density in airways, reduces exacerbation frequency, and improves quality of life and lung function in patients with chronic P. aeruginosa infection. In the last decade, tobramycin inhalation has become an important contributor to CF treatment as a means to control chronic infection and as a first-line treatment for the eradication of early acquisition of P. aeruginosa. Recently, a dry powder inhalation (DPI) form of tobramycin has become available, which is more convenient for administration and has comparable efficacy to the tobramycin solution. This DPI, the Podhaler™ (Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA), requires less time for treatment delivery and is more portable than a nebulizer, and so is a welcome additional therapeutic option for many patients.
Resumo:
Background: Ivacaftor has shown a clinical benefit in patients with cystic fibrosis who have the G551D-CFTR mutation and reduced lung function. Lung clearance index (LCI) using multiple-breath washout might be an alternative to and more sensitive method than forced expiratory volume in 1 s (FEV1) to assess treatment response in the growing number of children and young adults with cystic fibrosis who have normal spirometry. The aim of the study was to assess the treatment effects of ivacaftor on LCI in patients with cystic fibrosis, a G551D-CFTR mutation, and an FEV1 >90% predicted. Methods: This phase 2, multicentre, placebo-controlled, double-blind 2×2 crossover study of ivacaftor treatment was conducted in patients with cystic fibrosis, at least one G551D-CFTR allele, and an FEV1 >90% predicted. Patients also had to have an LCI higher than 7·4 at screening, age of 6 years or older, and a weight higher than or equal to 15 kg. Eligible patients were randomly allocated to receive one of two treatment sequences (placebo first followed by ivacaftor 150 mg twice daily [sequence 1] or ivacaftor 150 mg twice daily first followed by placebo [sequence 2]) of 28 days' treatment in each period, with a 28-day washout between the two treatment periods. Randomisation (ratio 1:1) was done with block sizes of 4, and all site personnel including the investigator, the study monitor, and the Vertex study team were masked to treatment assignment. The primary outcome measure was change from baseline in LCI. The study is registered at ClinicalTrials.gov, NCT01262352. Findings: Between February and November, 2011, 21 patients were enrolled, of which 11 were assigned to the sequence 1 group, and 10 to the sequence 2 group. 20 of these patients received treatment and 17 completed the trial (eight in sequence 1 group and 9 in sequence 2 group). Treatment with ivacaftor led to significant improvements compared with placebo in LCI (difference between groups in the average of mean changes from baseline at days 15 and 29 was -2·16 [95% CI -2·88 to -1·44]; p<0·0001). Adverse events experienced by study participants were similar between treatment groups; at least one adverse event was reported by 15 (79%) of 19 patients who received placebo and 13 (72%) of 18 patients who received ivacaftor. No deaths occurred during study period. Interpretation: In patients with cystic fibrosis aged 6 years or older who have at least one G551D-CFTR allele, ivacaftor led to improvements in LCI. LCI might be a more sensitive alternative to FEV1 in detecting response to intervention in these patients with mild lung disease. Funding: Vertex Pharmaceuticals Incorporated. © 2013 Elsevier Ltd.
Resumo:
It is well established that chronic inflammation underpins the development of a number of human cancers, with pro-inflammatory signaling within the tumor microenvironment contributing to tumor progression and metastasis. CXCL8 is an ELR+ pro-inflammatory CXC-chemokine which mediates its effects via signaling through two G protein-coupled receptors, CXCR1 and CXCR2. Elevated CXCL8-CXCR1/2 signaling within the tumor microenvironment of numerous cancers is known to enhance tumor progression via activation of signaling pathways promoting proliferation, angiogenesis, migration, invasion and cell survival. This review provides an overview of established roles of CXCL8-CXCR1/2 signaling in cancer and subsequently, discusses the possible strategies of targeting CXCL8-CXCR1/2 signaling in cancer, covering indirect strategies (e.g., anti-inflammatories, NFκB inhibitors) and direct CXCL8 or CXCR1/2 inhibition (e.g., neutralizing antibodies, small molecule receptor antagonists, pepducin inhibitors and siRNA strategies). Reports of pre-clinical cancer studies and clinical trials using CXCL8-CXCR1/2-targeting strategies for the treatment of inflammatory diseases will be discussed. The future translational opportunities for use of such agents in oncology will be discussed, with emphasis on exploitation in stratified populations.
Resumo:
BACKGROUND: Bone metastases frequently cause skeletal events in patients with metastatic castration-resistant prostate cancer. Radium-223 dichloride (radium-223) selectively targets bone metastases with high-energy, short-range α-particles. We assessed the effect of radium-223 compared with placebo in patients with castration-resistant prostate cancer and bone metastases.
METHODS: In this phase 3, double-blind, randomised ALSYMPCA trial, we enrolled patients who had symptomatic castration-resistant prostate cancer with two or more bone metastases and no known visceral metastases, who were receiving best standard of care, and had previously either received or were unsuitable for docetaxel. Patients were stratified by previous docetaxel use, baseline total alkaline phosphatase level, and current bisphosphonate use, then randomly assigned (2:1) to receive either six intravenous injections of radium-223 (50 kBq/kg) or matching placebo; one injection was given every 4 weeks. Randomisation was done with an interactive voice response system, taking into account trial stratification factors. Participants and investigators were masked to treatment assignment. The primary endpoint was overall survival, which has been reported previously. Here we report on time to first symptomatic skeletal event, defined as the use of external beam radiation to relieve bone pain, or occurrence of a new symptomatic pathological fracture (vertebral or non-verterbal), or occurence of spinal cord compression, or tumour-related orthopeadic surgical intervention. All events were required to be clinically apparent and were not assessed by periodic radiological review. Statistical analyses of symptomatic skeletal events were based on the intention-to-treat population. The study has been completed and is registered with ClinicalTrials.gov, number NCT00699751.
FINDINGS: Between June 12, 2008, and Feb 1, 2011, 921 patients were enrolled, of whom 614 (67%) were randomly assigned to receive radium-223 and 307 (33%) placebo. Symptomatic skeletal events occurred in 202 (33%) of 614 patients in the radium-223 group and 116 (38%) of 307 patients in the placebo group. Time to first symptomatic skeletal event was longer with radium-223 than with placebo (median 15·6 months [95% CI 13·5-18·0] vs 9·8 months [7·3-23·7]; hazard ratio [HR]=0·66, 95% CI 0·52-0·83; p=0·00037). The risks of external beam radiation therapy for bone pain (HR 0·67, 95% CI 0·53-0·85) and spinal cord compression (HR=0·52, 95% CI 0·29-0·93) were reduced with radium-233 compared with placebo. Radium-223 treatment did not seem to significantly reduce the risk of symptomatic pathological bone fracture (HR 0·62, 95% CI 0·35-1·09), or the need for tumour-related orthopaedic surgical intervention (HR 0·72, 95% CI 0·28-1·82).
INTERPRETATION: Radium-223 should be considered as a treatment option for patients with castration-resistant prostate cancer and symptomatic bone metastases.
FUNDING: Algeta and Bayer HealthCare Pharmaceuticals.
Resumo:
While personalised cancer medicine holds great promise, targeting therapies to the biological characteristics of patients is limited by the number of validated biomarkers currently available. The implementation of biomarkers has undergone many challenges with few biomarkers reaching cancer patients in the clinic. There have been many biomarkers that have been published and claimed to be therapeutically useful, but few become part of the clinical decision-making process due to technical, validation and market access issues. To reduce this attrition rate, there is a significant need for policy makers and reimbursement agencies to define specific evidence requirements for the introduction of biomarkers into clinical practice. Once these requirements are more clearly defined, in an analogous manner to pharmaceuticals, researchers and diagnostic companies can better focus their biomarker research and development on meeting these specific requirements, which should lead to the more rapid introduction of new molecular oncology tests for patient benefit.
Resumo:
A indústria da pasta e do papel é um sector importante da economia mundial, particularmente a que assenta em espécies de Eucalyptus. No entanto, essas indústrias geram quantidades significativas de correntes secundárias de subprodutos e resíduos de biomassa que podem ser exploradas em aplicações de valor acrescentado em vez de serem queimadas para produção de energia. Um exemplo nobre pode ser a produção de ácidos triterpénicos com estruturas dos tipos lupano, oleanano e ursano, dada a sua abundância em alguns destes resíduos, em particular na casca, adotando o conceito de biorrefinaria integrada numa fábrica de pasta. Estes compostos são conhecidos pelas suas inúmeras actividades biológicas, por exemplo, antioxidante, anti-inflamatória e antitumoral, e podem encontrar aplicações em produtos de elevado valor, tais como cosméticos, nutracêuticos ou farmacêuticos. Neste sentido, o estudo das potencialidades das cascas das espécies de eucalipto mais exploradas enquanto fontes de compostos triterpénicos é um tópico relevante. Por conseguinte, foram analisados e comparados em pormenor os teores e composições em ácidos triterpénicos (TTAs) das cascas externas de várias espécies de eucalipto (E. globulus, E. grandis, E. urograndis, E. maidenii e E. nitens). Os teores dos principais TTAs identificados nestas espécies variaram entre 4.5 g/kg no E. urograndis e 21.6 g/kg no E. nitens. Observou-se que as cascas externas de Eucalyptus de zonas temperadas e Mediterrânicas, nomeadamente E. nitens e E. globulus, são mais ricas em TTAs que as espécies de regiões tropicais e subtropicais. Além disso, a casca externa do E. globulus é claramente a mais rica em ácidos com estruturas do tipo ursano enquanto a do E. nitens é a mais rica em ácidos do tipo oleanano e lupano. Estes resultados levaram-nos a estudar a extração dos TTAs da casca de Eucalyptus, bem como a sua posterior concentração e purificação, a qual foi efetuada por extração sólido-líquido convencional combinada com a precipitação de solutos, e por extração com fluidos supercríticos (SFE). No que diz respeito à primeira abordagem referida, foi desenvolvido neste trabalho um método patenteado que permite obter extratos enriquecidos em TTAs das cascas de eucalipto baseado em tecnologias disponíveis no imediato. Em relação à segunda abordagem, e de forma a apostar em processos de baixo impacto ambiental exigidos pelas biorrefinarias do futuro, a SFE surge como uma opção natural. Assim, foi efetuada a SFE da casca caduca do E. globulus com dióxido de carbono puro e modificado para recuperar a fração de TTAs, e os resultados foram comparados com os obtidos por extração em Soxhlet com diclorometano. Foram realizados estudos preliminares sobre a influência da pressão (100-200 bar), a adição de co-solvente (0, 5 e 8% m/m de etanol), e operação em múltiplos passos a fim de avaliar a aplicabilidade da alternativa supercrítica para a sua produção eficiente e selectiva. Os resultados destacaram a influência da pressão e o importante papel resumo (cont.) desempenhado pelo co-solvente neste processo, cujo efeito foi mais relevante do que o aumento da pressão em várias dezenas de bar. Este trabalho foi depois otimizado, usando o planeamento factorial de experiências e a metodologia de superfícies de resposta, para analisar a influência da temperatura (40-60 ºC), pressão (100-200 bar), e teor de etanol (0.0-5.0% m/m) na recuperação dos TTAs e respectiva concentração nos extractos. Nestes intervalos, as melhores condições de operação encontradas foram 200 bar, 40 °C e 5% de etanol, para as quais os modelos de regressão estatisticamente validados previram um rendimento de extração de 1.2% com 50% de concentração em TTAs, correspondendo ao rendimento em TTAs de 5.1 g/kg de casca e uma recuperação de 79.2% comparativamente ao valor do Soxhlet. Os TTAs livres e acetilados apresentaram tendências de extracção bastante distintas devido às suas diferentes afinidades para o CO2 causadas pelas diferentes polaridades: os derivados acetilados aproximam-se de um patamar máximo a cerca de 200 bar e 5% de etanol, enquanto a extração dos TTAs livres apresenta uma tendência sempre crescente no intervalo de condições estudado. Foram também medidas curvas cumulativas de SFE da casca do E. globulus de forma a analisar o comportamento cinético do processo em termos de rendimento total, rendimento em TTAs, rendimento em TTAs livres, rendimento em TTAs acetilados, e concentração dos TTAs nos extractos. Foi analisada a influência da pressão, temperatura, teor de co-solvente e caudal do dióxido de carbono sobre as respostas anteriores. Os dados experimentais foram modelados com os modelos Logístico, de Dessorção, de Placa Plana Simples, e de Difusão. Na globalidade, os resultados confirmaram que a pressão e o teor de etanol têm um efeito significativo sobre as curvas de extração, os rendimentos finais e as concentrações dos extratos, e mostraram a presença de limitações externas à transferência de massa em alguns ensaios. Mais uma vez, as famílias individuais de TTAs livres e acetilados apresentaram diferentes tendências de extracção. A modelação permitiu-nos confirmar não só o importante papel desempenhado pela difusão intraparticular na SFE, mas também a contribuição da resistência no filme em alguns ensaios. Após a análise de todos os resultados, foi efetuado um ensaio em duas etapas em série, possibilitando o enriquecimento do teor em TTAs no extracto devido às diferentes condições adotadas em cada etapa. Por último, um éster metílico de um ácido triterpénico do tipo oleanano - morolato de metilo - foi identificado pela primeira vez enquanto componente da casca de Eucalyptus na casca externa do Eucalyptus grandis x globulus, onde ocorre em teores elevados. A sua extração com CO2 supercrítico foi também realizada, visando a conceção de uma alternativa de extração ambientalmente benigna para este composto. A 200 bar e 60 ºC, a remoção do morolato de metilo atingiu um patamar às 6 h para 5.1 kg h-1 de CO2 / kg de casca. Em geral, e de forma semelhante à SFE da casca do E. globulus, os TTAs acetilados foram mais significativamente extraídos quando comparados com os seus ácidos livres, o que está diretamente relacionado com a natureza menos polar destas moléculas. O trabalho apresentado nesta tese é uma contribuição para a valorização de uma corrente de biomassa com baixo valor na indústria de pasta em duas vertentes complementares. Por um lado, aumentou o conhecimento da composição lipofílica das cascas de Eucalyptus spp. com interesse comercial para a produção de pasta, destacando o seu potencial enquanto fontes de ácidos triterpénicos. Por outro lado, foram desenvolvidos dois processos alternativos e facilmente integráveis numa fábrica de pasta para a sua exploração a partir da casca: um baseado em tecnologias convencionais bem estabelecidas a nível industrial, prevendo a sua aplicação a curto prazo, e um outro baseado na SFE, seguindo as tendências das futuras biorrefinarias.
Resumo:
The introduction of chemicals into the environment by human activities may represent a serious risk to environmental and human health. Environmental risk assessment requires the use of efficient and sensitive tools to determine the impact of contaminants on the ecosystems. The use of zebrafish for the toxicity assessment of pharmaceuticals, drugs, and pollutants, is becoming well accepted due to zebrafish unique advantages for the screening of compounds for hazard identification. The aim of the present work is to apply toxicogenomic approaches to identify novel biomarkers and uncovered potential modes of action of classic and emergent contaminants able to disrupt endocrine systems, such as the Retinoic Acid Receptor, Retinoid X Receptor and the Aryl Hydrocarbon Receptor. This study relies on different nuclear and cytosolic protein receptors and other conditional (ligand- or stress- activated) transcriptional factors that are intimately involved in the regulation of defensome genes and in mechanisms of chemical toxicity. The transcriptomic effects of organic compounds, endogenous compounds, and nanoparticles were analysed during the early stages of zebrafish development. Studying the gene expression profiles of exposed and unexposed organisms to pollutants using microarrays allowed the identification of specific gene markers and to establish a "genetic code" for the tested compounds. Changes in gene expression were observed at toxicant concentrations that did not cause morphological effects. Even at low toxicant concentrations, the observed changes in transcript levels were robust for some target genes. Microarray responses of selected genes were further complemented by the real time quantitative polymerase chain reaction (qRT-PCR) methodology. The combination of bio-informatic, toxicological analyses of differential gene expression profiles, and biochemical and phenotypic responses across the treatments allowed the identification of uncovered potential mechanisms of action. In addition, this work provides an integrated set of tools that can be used to aid management-decision making by improving the predictive capability to measure environmental stress of contaminants in freshwater ecosystems. This study also illustrates the potential of zebrafish embryos for the systematic, large-scale analysis of chemical effects on developing vertebrates.
Resumo:
Endocrine disruptors and pharmaceuticals are considered to be concerning environmental contaminants. During the last two decades, studies dealing with the occurrence and fate of these emerging contaminants in the aquatic environment have raised attention and its number is constantly increasing. The presence of these contaminants in the environment is particularly important since they are known to induce adverse effects in the ecosystems even at extremely low concentrations. Estrogens and antibiotics, in particular, are identified as capable of induce endocrine disruption and contribute for the appearance of multi-resistant bacteria, respectively. A better assessment and understanding of the real impact of these contaminants in the aquatic environment implies the evaluation of their occurrence and fate, which is the main aim of this Thesis. Two estrogens (17-estradiol and 17-ethinylestradiol) and an antibiotic (sulfamethoxazole) were the contaminants under study and their occurrence in surface and waste waters was assessed by the implementation of enzyme linked immunosorbent assays (ELISAs). The assays were optimized in order to accomplish two important aspects: to analyze complex water samples, giving special attention to matrix effects, and to increase the sensitivity. Since the levels of these contaminants in the environment are extremely low, a pre-concentration methodology was also object of study in this Thesis. Dispersive liquid-liquid microextraction (DLLME) was developed for the preconcentration of E2 and EE2, subsequently quantified by either highperformance liquid chromatography (HPLC) and the previously optimized ELISAs. Moreover, the use of anthropogenic markers, i.e. indicators of human presence or activity, has been discussed as a tool to track the origin and type of contamination. An ELISA for the quantification of caffeine, as an anthropogenic marker, was also developed in order to assess the occurrence of human domestic pollution in Portuguese surface waters. Finally, photodegradation is considered to be one of the most important pathways contributing for the mitigation of pollutants’ presence in the aquatic environment. Both direct and indirect photodegradation of E2 and EE2 were evaluated. Since the presence of humic substances (HS) is known to have a noticeable influence on the photodegradation of pollutants and in order to mimic the real aquatic environment, special attention was given to the influence of the presence and concentration of different fractions of HS on the photodegradation of both hormones.
Resumo:
Photodegradation is considered to be one of the most important processes of elimination of pharmaceutical drugs from natural water matrices. The high consumption and discharge of these substances, in particular antidepressants, to the aquatic environment supports the need to study degradation processes. This dissertation aimed at studying the direct and indirect photodegradation of sertraline, an antidepressant known for its persistence in the environment, and the evaluation of the influence of environmentally relevant factors in its photodegradation. The photodegradation experiments were developed under simulated solar light and the irradiation times converted to summer sunny days (SSD), an equivalent time in natural environmental conditions. The direct photodegradation was evaluated in solutions of sertraline prepared in ultrapure water and the indirect photodegradation was studied through the addition of photosensitizers (humic substances, Fe(III), nitrates and oxygen). Further irradiation studies were perfomed in aqueous samples collected from two wastewater treatment plants, Vouga river and Ria de Aveiro. The samples were chemically characterized (dissolved organic carbon, nitrates and nitrites and iron determination and UV/Vis spectroscopy). The quantification of sertraline was done by HPLC-UV and photoproducts from direct photodegradation were identified by electrospray mass spectrometry. An observed direct photodegradation rate of sertraline of 0.0062 h-1 was determined, corresponding to a half-life time of 111 h (equivalent to 29 SSD). A significant influence of photosensitizers was observed, the best results being achieved in irradiations of sertraline with humic acids, obtaining a half-life time of 12 h. This was attributed to the hydrophobicity of this substance and higher absortivity in the UV/Vis wavelength, which promote processes of indirect photodegradation. The degradation of sertraline in natural samples was also enhanced comparatively to the direct photodegradation, achieving half-life times between 10 and 25h; the best results were achieved in samples from the primary treatment of a wastewater treatment plant and Ria de Aveiro, with half-life times of 10 and 16 h, respectively. A total of six photoproducts formed during the direct photodegradation of sertraline were identified, three of which were not yet identified in the literature. The main factors contributing to the degradation of sertraline were analysed but this was not fully accomplished, requiring further studies of the composition of the natural matrices and the combined influence of distinct photosensitizers during the irradiation. Nevertheless, it was concluded that the photodegradation of sertraline is greatly influenced by indirect photodegradation processes, promoted by the presence of photosensitizers.
Resumo:
Tese de doutoramento, Farmácia (Bromatologia), Universidade de Lisboa, Faculdade de Farmácia, 2014
Resumo:
Tese de doutoramento, Química (Química Analítica), Universidade de Lisboa, Faculdade de Ciências, 2014
Resumo:
Thesis (Ph.D.)--University of Washington, 2015