TEDE Collection:

Produção de não-tecido por eletrofiação para análise de dissolução rápida de paracetamol em nanofibras de poli(1-vinilpirrolidona)-co-(acetato de vinila)

Fri, 07 Mar 2025 00:00:00 GMT

Title: Produção de não-tecido por eletrofiação para análise de dissolução rápida de paracetamol em nanofibras de poli(1-vinilpirrolidona)-co-(acetato de vinila) Autor: Chang, Vanessa Rong Jen Primeiro orientador: Dragunski, Douglas Cardoso Abstract: The study investigates ways to improve the dissolution of paracetamol for patients with swallowing difficulties, using the sublingual administration of the drug in a non-woven format, which allows rapid release and avoids the need to swallow and chew. The electrospinning technique was applied to incorporate paracetamol (PCM) into the polymer poly(1-vinylpyrrolidone)-co-(vinyl acetate) (PVP/VA), which reduces the crystallinity of the drug, promoting an amorphous form of greater availability. The study included characterization of the electrospinning solution (viscosity and conductivity) and the resulting fibers, using scanning electron microscopy (SEM) for morphological analysis, Fourier transform infrared spectroscopy (FTIR) for identification of functional groups, differential scanning calorimetry DSC and Thermogravimetric analysis TGA for thermal properties, and X-ray diffraction (XRD) to evaluate crystallinity. The release test was performed on artificial saliva to check the dissolution time. Results indicate that higher concentration of PCM in fibers increases crystallinity, while lower concentrations result in amorphous fiber degrading more easily due to the disordered molecular state. Therefore, nonwovens with more concentrated PCM present the presence of crystallinity, as a result of the dissolution of PCM also promotes rapid dissolution of PCM in sublingual formulations, offering a promising alternative to improve the bioavailability of the drug and expanding its accessibility for patients with swallowing difficulties. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação

Avaliação da concentração de aciclovir em não-tecido eletrofiado de poli(1-vinilpirrolidona)-co-(acetato de vinila) para dissolução rápida

Wed, 03 Dec 2025 00:00:00 GMT

Title: Avaliação da concentração de aciclovir em não-tecido eletrofiado de poli(1-vinilpirrolidona)-co-(acetato de vinila) para dissolução rápida Autor: Pfeifer, Gabriel das Neves Primeiro orientador: Dragunski, Douglas Cardoso Abstract: Herpes simplex virus (HSV), especially type 1 (HSV-1), is highly prevalent and causes recurrent orofacial infections. Acyclovir (ACV) is the standard treatment, but its low solubility limits bioavailability. Electrospinning enables the production of nanofibers with high surface area, enhancing rapid drug release. The PVP/VA copolymer combines hydrophilic and hydrophobic characteristics that aid in compound solubilization and transport, making it a promising matrix for drug‐delivery systems. However, few studies explore electrospun PVP/VA, and none apply ACV for topical use. This work develops and characterizes ACV-loaded PVP/VA nanofibers, evaluating their physicochemical and morphological properties and their potential for rapid release against HSV-1. FTIR analysis revealed interactions between ACV and PVP/VA, evidenced by shifts in the hydroxyl band. ACV increased fiber diameter but improved jet stability, as SEM analysis showed fewer beads. XRD indicated that ACV and PVP/VA do not form a fully homogeneous solid solution but likely a blend, since crystalline peaks remained detectable, although crystallinity was altered. DSC confirmed the disappearance of the ACV melting peak in polymer-containing samples. The release kinetics were best described by the Weibull model, with a diffusional mechanism (β < 1). Simulated dissolution showed complete solubilization of the electrospun material within 4 s, whereas pure ACV remained undissolved. Overall, the developed system is promising for rapid-release topical dressings or sublingual patches for HSV-1 treatment. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação

Uma revisão sobre o uso de adjuvantes na agricultura

Fri, 05 Sep 2025 00:00:00 GMT

Title: Uma revisão sobre o uso de adjuvantes na agricultura Autor: Meotti, Mauricio Luiz Primeiro orientador: Lindino, Cleber Antônio Abstract: The application of products in agricultural spraying has been widely used, as it aids in plant development in various ways, such as pest control and nutrition. However, to achieve good application efficiency, these products are not always easy to stabilize when used in mixtures, nor are they always compatible with each other, as they can form foam, cause losses during application, lack uniformity of contact with the plant, among other application problems. This work describes the types of adjuvants, their specific applications, the problems that mixtures of pesticides and fertilizers can cause and presents the main solutions. A literature review in scientific journal databases was conducted to evaluate the main research areas in the field, showing that there are numerous studies dispersed across different countries, with the authors of the research concentrated in the United States, Brazil, and China. It was also found that there are few patents filed or granted at the INPI (Brazilian National Institute of Industrial Property), indicating little concern for the intellectual property protection of products or processes produced in national companies. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação

Biossíntese de CuO/Cu2O usando extrato aquoso de Curcuma longa L. para aplicação em reações de cicloadição [3+2] entre azidas e alquinos

Wed, 10 Sep 2025 00:00:00 GMT

Title: Biossíntese de CuO/Cu2O usando extrato aquoso de Curcuma longa L. para aplicação em reações de cicloadição [3+2] entre azidas e alquinos Autor: Pinto, Felipe Augusto Chimenez Primeiro orientador: Manarin, Flávia Giovana Abstract: The development of new materials through nanotechnology has gained increasing attention due to their broad applicability, especially metallic nanoparticles and metal oxides such as copper and copper oxides. Conventional synthesis methods are gradually being replaced by green approaches, aiming to reduce the use of toxic reagents and expensive, less sustainable equipment. These eco-friendly methods utilize natural sources such as microorganisms, algae, and plant extracts. Curcuma longa L., for instance, is a plant well known for its anti-inflammatory, antimicrobial, and antioxidant properties. In this context, the present study aims to synthesize copper oxide nanoparticles (CuO/Cu₂O) using an aqueous extract of Curcuma longa L. and anhydrous copper sulfate as the precursor, characterize them using UV-Vis, FTIR, XRD, SEM, TEM and EDX techniques, and evaluate their catalytic potential. The synthesis was carried out by adding the plant extract to a 100 mM precursor solution, followed by centrifugation and drying of the resulting material. The obtained nanoparticles were calcined to investigate their morphological structure and purity. An optimization study was also conducted using the nanoparticles as a catalyst in multicomponent click chemistry reactions. Nanoparticle formation was confirmed through solution color changes, optical features in the UV-Vis spectrum, and the presence of reducing functional groups identified via FTIR. XRD patterns exhibited diffraction peaks corresponding to CuO and Cu₂O, with average crystallite sizes of 15.88 nm and 16.71 nm, respectively. TEM images revealed nearly spherical structures presenting an average particle diameter of 8 nm. The synthesis proceeded with the optimization of the reaction conditions, employing 1 mg of catalyst and achieving yields of up to 96%. These results demonstrate the successful development of a material synthesized via a green route, with promising catalytic efficiency for click chemistry reactions. In this way, this work contributes to the advancement of sustainable methodologies for the production of new materials and their application in organic synthesis. Publisher: Universidade Estadual do Oeste do Paraná Tipo do documento: Dissertação