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- Ciclodextrinas: formação de complexos e sua aplicação farmacêuticaPublication . Oliveira, Rita; Santos, Delfim; Barata, PedroO número de moléculas com problemas de solubilidade, biodisponibilidade e permeabilidade tem vindo a aumentar. As ciclodextrinas são oligossacarídeos cíclicos com uma cavidade central hidrófoba, cuja estrutura permite formar complexos de inclusão estáveis com diversos fármacos. A complexação com ciclodextrinas permite optimizar os diversos sistemas transportadores constituídos por este tipo de fármacos, assim como solucionar problemas devidos a propriedades indesejáveis como instabilidade, más características organolépticas ou potencial irritação. The number of molecules with problems of solubility, bioavailability and permeability is increasing. Cyclodextrins are cyclic oligosaccharides with a hydrophobic central cavity, whose structure can form stable inclusion complexes with various drugs. Complexation allows the optimization of drug delivery of such drugs, and to solve problems due to undesirable properties such as instability, poor organoleptic characteristics or irritation.
- Tecnologia Farmacêutica II - trabalhos laboratoriais em vídeoPublication . Oliveira, Rita
- Manual de apoio pedagógico: Tecnologia Farmacêutica IIPublication . Oliveira, Rita
- Effect of cyclodextrins and pH on the permeation of tetracaine: supramolecular assemblies and release behaviorPublication . Teixeira, Raquel S.; Veiga, Francisco J.B.; Oliveira, Rita; Jones, Stuart A.; Silva, Sérgio M.C.; Carvalho, Rui A.; Valente, Artur J.M.This work provides a new insight on fundamental principles of the interaction mechanism between two forms of tetracaine – a potent local anesthetic – both in neutral (TC) and ionized (TC+) states, with beta- (b-CD) and hydroxypropyl-beta-cyclodextrin (HP-b-CD), and how such interactions affect the transport of tetracaine, at different concentrations, across a model membrane. The kinetics and mechanism of TC release from HPMC gels is also evaluated giving an insight on the role of cyclodextrin on the tetracaine transport. HPLC, fluorescence and NMR spectroscopies provided solid physicochemical knowledge of these systems and in vitro studies were performed to obtain relevant data on the transport and mechanism parameters. HPLC and fluorescence spectroscopy data revealed that tetracaine interacts with both cyclodextrins on a 1:1 stoichiometry but it is observed that neutral tetracaine forms more stables complexes (ca. 1050 M 1 for both cyclodextrins) than in its ionized form (628 and 337 M 1 for b-CD and HP-b-CD respectively). Despite of that, no host–guest interactions take place as seen by ROESY. This study clearly demonstrates that both forms of tetracaine are successfully released from the formulations at a controlled rate, following a Super-Case transport mechanism and the transport of tetracaine can be tuned by using cyclodextrins.
- Influence of gut microbiota dysbiosis on brain function: a systematic reviewPublication . Almeida, Cátia; Oliveira, Rita; Soares, Raquel; Barata, PedroBackground: For almost a century it has been recognized that human possess a varied and dens microbial ecosystem called the human microbiota, yet we are still beginning to understand many of the roles that these microorganisms play in human health and development. It is thought that under certain circumstances such as dysbiosis, the microbiota can cause diseases, where the central nervous system (CNS) has an important relevance and where the “gut-brain axis” will play a major role. Aims: This review investigated the influence of the gut microbiota on brain function, trying to demonstrate whether dysbiosis influences CNS diseases or whether it is the disease that causes dysbiosis, highlighting the existing literature within this field. Methods:We performed a systematic literature search in EMBASE, PubMed, and Cochrane combining the terms “gut microbiota,” “dysbiosis,” and “CNS diseases” to identify those whom reported some influence or relation between dysbiosis of gut microbiota and CNS diseases. For the present systematic review, we only included systematic reviews or meta-analysis. Results: The EMBASE, PubMed, and Cochrane were systematically searched, considering only systematic reviews or metaanalysis. Nine studies comprising 705 articles were included in this review. Those 9 systematic reviews consist in 2 about autism spectrum disorder, 1 in dementia, 1 in depression, 2 in autoimmune diseases, 1 in schizophrenia, and 2 in some altered brain function. Available data characterizing several neural diseases demonstrate a significant correlation between dysbiosis and CNS diseases, strengthen the evidence that dysbiosis of gut microbiota may correlate with abnormalities in CNS patients. Conclusions: Although there is a clear need for more investigations to better understand the role of the gut microbiota in CNS diseases, the modulation of the nervous system by the microbiota is clear, continuing to be the subject of continuous research. We need to fully understand the mechanisms by which the microbiota interacts with the human brain, and therefore what’s the connection between dysbiosis and pathologies such depression, dementia, autism, or schizophrenia.
- Veiculação de fármacos para o cólonPublication . Barata, Pedro; Oliveira, Rita; Santos, Delfim; Strusi, OrazioLuca; Veiga, FranciscoA veiculação de fármacos para o cólon tem atraído a atenção de muitos investigadores interessados no tratamento de patologias locais e no seu potencial para a veiculação de proteínas e peptídeos. Para desenvolver estes sistemas é fundamental compreender o cólon enquanto local de veiculação de fármacos, em particular a sua capacidade de absorção e o tempo necessário para o atingir. Dois tipos de abordagens podem ser utilizados, libertação retardada ou libertação específica no cólon. O primeiro caso é menos específico e consiste em formulações preparadas de forma a retardar a libertação de fármaco até o sistema farmacêutico atingir o cólon. O segundo caso explora as propriedades de pH, actividade enzimática e pressão intraluminal do cólon para promover a libertação colónica de fármacos. Colon targeting has been attracting interest for those interested in treating local pathologies and administrating proteins and peptides. In order to develop these systems a perfect understanding of the colonic region is compulsory. two main strategies are used: delayed release and specific release. the first one, less specific, consists in postponing release from the system until it reaches de colon. the second one uses colon properties as pH, enzymatic activity and intraluminal pressure to trigger colonic drug release.
- Protocolos laboratoriais de Tecnologia Farmacêutica IIPublication . Oliveira, Rita
- Aplicação de ciclodextrinas na promoção da adesão à terapêutica dermatológica com corticosteroidesPublication . Garrido, Manuela; Oliveira, Bárbara; Oliveira, Rita; Almeida, Isabel; Garrido, Jorge
- Development of an in vitro test for the evaluation of the sweat-resistance efficacy of decorative cosmetics – an exploratory studyPublication . Costa, Silvana; Oliveira, Rita; Sousa-Lobo, José Manuel; Almeida, Isabel
- Estabilidade dos medicamentos manipuladosPublication . Pombal, Rute; Barata, Pedro; Oliveira, RitaActualmente assiste-se a uma cada vez maior solicitação dos Medicamentos Manipulados, principalmente com o objectivo de encontrar soluções terapêuticas não oferecidas pela Indústria Farmacêutica. A Manipulação Magistral de Medicamentos deve obedecer a vários parâmetros que são determinados pela legislação e por diferentes Farmacopeias. Esses parâmetros visam o garante da qualidade, segurança e eficácia destes medicamentos sendo a sua estabilidade um factor chave. Este artigo visa apresentar os principais factores que condicionam a estabilidade dos medicamentos manipulados e condicionam a atribuição de um prazo de validade aos mesmos. Nowadays there is an increase in the request for compounded medicines or extemporaneous formulations, mainly for situations that are not covered by the Pharmaceutical Industry. Compounded medicines must follow quality parameters that are required by law and are included in different pharmacopoeias. This review aims to present the main factors that condition compounded formulations stability and hence determine expiry dates.