Browsing by Author "Silva, Ana Catarina"
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- Advances in nanoparticulate carriers for oral peptides and proteins: polymeric vs. lipid nanoparticlesPublication . Silva, Ana Catarina; Santos, D.; Ferreira, D.C.; Souto, Eliana B.
- Advances in pharmaceutical biotechnologyPublication . Silva, Ana Catarina; Lopes, Carla Martins; Lobo, José M.S.; Amaral, Maria H.
- Application of the Quality-by-Design (QbD) approach to improve the nose-to-brain delivery of diazepam-loaded Nanostructured Lipid Carriers (NLCs)Publication . Costa, Cláudia Pina; Cunha, Sara; Peixoto, Andreia F.; Moreira, João Nuno; Lobo, José Manuel Sousa; Silva, Ana CatarinaThe intranasal administration of nanostructured lipid carriers (NLCs) has been suggested as a promising strategy to improve the fast treatment of epilepsy. This route allows for drug passage directly from the nose to the brain, avoiding the need of bypassing the blood–brain barrier. In addition, the quality-by-design (QbD) approach is a useful tool for the optimization of manufacturing variables, resulting in effective and safe pharmaceutical formulations. The aim of this work was to use the QbD approach to optimize a NLCs formulation for the nose-to-brain delivery of diazepam. The studies began with the screening of excipients and the assessment of the lipid-drug compatibility. The central composite design was used to evaluate the effects of critical material attributes (CMAs) (ratio of solid and liquid lipids and the amount of drug and emulsifiers) on the CQAs of the diazepam-loaded NLCs formulation (particle size, polydispersity index (PDI), zeta potential (ZP) and encapsulation efficiency (EE)). The results showed that the most adequate ratios of lipids and emulsifiers were 6.65:2.85 and 4.2:0.3 (%, w/w), with values of 84.92 nm, 0.18, −18.20 mV and 95.48% for particle size, PDI, ZP and EE, respectively. This formulation was selected for further studies related to the optimization of critical process parameters (CPPs).
- Applications of polymeric and lipid nanoparticles in ophthalmic pharmaceutical formulations: present and future considerationsPublication . Almeida, Hugo; Amaral, Maria Helena; Lobão, Paulo; Silva, Ana Catarina; Lobo, José Manuel SousaThe unique properties and characteristics of ocular tissues and the whole set of defence mechanisms of the ocular globe make the instillation of ocular drugs into a difficult task with a low rate of therapeutic response. One of the challenges for the new generation of ophthalmic pharmaceutical formulations is to increase the bioavailability of drugs administered by the ocular route and, therefore, their therapeutic efficacy. This can be achieved with the use of some strategies that provide an increase in the formulation pre-corneal residence time, mucoadhesion and penetration across the eye tissues. Colloidal carrier systems have been very successfully used for the selective and targeted delivery of drugs for several routes of administration. In this context, nanoparticles prepared with specific polymers or lipids and coated, dispersed or suspended in polymer solutions with mucoadhesion properties or in situ gelling properties will be an excellent strategy that deserves attention and further research. In this review, the characteristics and main properties of polymeric and lipid nanoparticles are discussed and examples and advantages of the application of these colloidal carrier systems for the ophthalmic administration of drugs are presented. The future directions of the research required in this specific field are also presented.
- Biosimilar medicines used for cancer therapy in Europe: a reviewPublication . Santos, Sofia B.; Lobo, José M. Sousa; Silva, Ana CatarinaThis article provides an updated review of the biosimilar medicines approved for cancer therapy in the European Union (EU). First we discuss the most relevant aspects for the development and approval of biosimilar medicines. We then present the oncological biosimilar drugs currently used, which include epoetins (alpha and zeta), filgrastim, and monoclonal antibodies (rituximab, trastuzumab and bevacizumab). Among the clinical applications of biosimilar medicines, cancer therapy remains the main target area and more approved biosimilars are expected over the next few years, providing cost-effective drugs to more patients. Furthermore, comprehensive pharmacovigilance studies are going on, monitoring the marketed biosimilars, and providing more feasible information to clinicians regarding the safety and efficacy of these medications.
- Biotechnology applied to cosmetics and aesthetic medicinesPublication . Gomes, Cátia; Silva, Ana Catarina; Marques, Ana Camila; Sousa Lobo, José; Amaral, Maria HelenaBiotechnology uses microorganisms and/or enzymes to obtain specific products through fermentative processes and/or genetic engineering techniques. Examples of these products are active ingredients, such as hyaluronic acid, kojic acid, resveratrol, and some enzymes, which are used in skin anti-aging products. In addition, certain growth factors, algae, stem cells, and peptides have been included in cosmetics and aesthetic medicines. Thus, biotechnology, cosmetics and aesthetic medicines are now closely linked, through the production of high-quality active ingredients, which are more effective and safer. This work describes the most used active ingredients that are produced from biotechnological processes. Although there are a vast number of active ingredients, the number of biotechnological active ingredients reported in the literature is not significantly high.
- Células estaminais na regeneração da pele: aplicações terapêuticas e cosméticasPublication . Silva, Ana Catarina; Barata, RitaTendo em conta a capacidade das células estaminais para se autorrenovarem e diferenciarem em vários tipos de células do organismo, a sua utilização terapêutica torna-se interessante, por exemplo, ao nível da regeneração da pele. Nesse sentido, as células estaminais têm sido testadas para o tratamento/cicatrização de feridas originadas pela exposição ao calor e à radiação, bem como em úlceras diabéticas. A eficácia da utilização destas células tem sido demonstrada por vários investigadores, tendo-se verificado que promovem a reepitelização e a neovascularização, e reduzem a formação de cicatrizes, sem provocar respostas inflamatórias ou imunológicas. Também na área da cosmética tem sido observado o potencial das células estaminais, em particular, as células de origem vegetal, para retardar o processo natural de envelhecimento da pele, através da proteção das células estaminais autólogas e estimulação da sua proliferação. No entanto, é necessário realizar mais estudos clínicos e procurar novos ingredientes ativos, de forma a poder concluir, com maior rigor, a eficácia destas aplicações.
- Characterization and biocompatibility evaluation of cutaneous formulations containing lipid nanoparticlesPublication . Eiras, F.; Amaral, M.H.; Silva, R.; Martins, E.; Lobo, J.M. Sousa; Silva, Ana CatarinaNanostructured lipid carriers (NLC) are well-known systems that show effectiveness to improve skin hydration, being suggested for cosmetic and dermatological use. Nonetheless, NLC dispersions present low viscosity, which is non-attractive for cutaneous application. To circumvent this drawback, the dispersions can be gelled or incorporated in semisolid systems, increasing the final formulation consistency. In this study, we prepared a hydrogel based on NLC containing vitamin E (HG-NLCVE) and evaluated its suitability for cutaneous application. The experiments started with the HG-NLCVE characterization (organoleptic analysis, accelerated stability, particle size, morphology, pH, texture and rheology). Afterwards, in vitro experiments were carried out, evaluating the formulation biocompatibility (MTT and Neutral Red) and irritant potential (Hen's egg test on the chorioallantoic membrane, HET-CAM) for cutaneous application. The results showed that the HG-NLCVE has adequate features for skin application, is biocompatible and non-irritant. From this study, it was predicted the in vivo irritant potential of the developed formulation, avoiding the need to perform a high number of tests on human volunteers. Regarding vitamin E and NLC potential to improve skin hydration, we suggest that the HG-NLCVE could be used in cosmetic (e.g. moisturizers and anti-aging) or dermatologic (e.g. xerosis and other skin disorders) products.
- Current applications of pharmaceutical biotechnologyPublication . Silva, Ana Catarina; Moreira, João Nuno; Lobo, José Manuel Sousa; Almeida, HugoThis book offers an authoritative review of biopharmaceuticals and their clinical relevance. Biopharmaceuticals have been showing high therapeutic potential by means of biological and biosimilar medicines, particularly for the treatment of cancer, chronic diseases (e.g. diabetes, Crohn's disease, psoriasis and rheumatoid arthritis), neurodegenerative disorders (e.g. multiple sclerosis), and they have also been contributing to the progress of innovative therapies such as assisted reproductive medicine. Since the eighties, several biopharmaceuticals have been approved and, due to patents expiration, many biosimilars are also marketed. In this book, readers will find the most relevant updated information about the main clinical applications of pharmaceutical biotechnology. The authors provide expert analysis about the industrial challenges of recombinant proteins and the different classes of biopharmaceuticals, including monoclonal antibodies, vaccines, growth factors and stem cells. Topics such as bioprinting technologies in tissue engineering, gene therapy and personalized medicine are also covered in this book. Professionals, students and researchers interested in this field will find this work an important account.
- Current progresses on nanodelivery systems for the treatment of neuropsychiatric diseases: Alzheimer’s and SchizophreniaPublication . Silva, Ana Catarina; González-Mira, E.; Lobo, J.M. Sousa; Amaral, M.H.Currently Alzheimer's disease and schizophrenia are both well-established neuropsychiatric diseases. Nonetheless, the treatment of these disorders is not unanimous and fully effective. As a consequence, several approaches have been studied to improve patient's conditions. In this context, the development of new drug nanodelivery systems to increase drug bioavailability and reduce adverse effects has been claimed as a good option. Among these systems we focus on the ones that seem to be most promising, such as lipidbased systems (e.g. liposomes, nanoemulsions and lipid nanoparticles), drug nanocrystals, polymeric nanoparticles and micelles. Moreover, the application of these systems by means of alternative administration routes is also discussed. Regardless of the satisfactory results and the associated progresses that have been done in the last years, more studies are required to quickly licence the application of drug nanodelivery systems in human medicines.