Publications by authors named "Porav S"

The objective of this work was to develop a fused deposition modeling (FDM) 3D printed immediate release (IR) tablet with flexibility in adjusting the dose of the active pharmaceutical ingredient (API) by scaling the size of the dosage form and appropriate drug release profile steadiness to the variation of dimensions or thickness of the deposited layers throughout the printing process. Polyvinyl alcohol-based filaments with elevated API content (50% w/w) were prepared by hot melt extrusion (HME), through systematic screening of polymeric formulations with different drug loadings, and their printability was evaluated by means of mechanical characterization. For the tablet fabrication step by 3D printing (3DP), the Quality by Design (QbD) approach was implemented by employing risk management strategies and Design of Experiments (DoE).

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In this paper, the photodynamic effect of a ternary nanocomposite (TiO-Ag/graphene) on Escherichia coli bacteria and two human cell lines: A375 (melanoma) and HaCaT (keratinocyte) after exposure to different wavelength domains (blue, green or red-Light Emitting Diode, LED) was analyzed. The results obtained through bioassays were correlated with the morphological, structural and spectral data obtained through FT-IR, XPS and UV-Vis spectroscopy, powder X-Ray diffractometry (XRD) and STEM/EDX techniques, leading to conclusions that showed different photodynamic activation mechanisms and effects on bacteria and human cells, depending on the wavelength. The nanocomposite proved a therapeutic potential for blue light-activated antibacterial treatment and revealed a keratinocyte cytotoxic effect under blue and green LEDs.

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In the present study, the synthesis of superparamagnetic collagen-based nanocomposite hydrogels with tunable swelling, mechanical and magnetic properties is reported. The fabrication strategy involved the preparation of pristine collagen type-I hydrogels followed by their immersion in highly stable aqueous solutions containing pre-formed double-layer oleic acid-coated hydrophilic magnetite nanoparticles (OA.OA.

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The study focused on the fluid-bed granulation process of a product with two active pharmaceutical ingredients, intended for coated tablets preparation and further transfer to industrial scale. The work aimed to prove that an accurate control of the critical granulation parameters can level the input material variability and offer a user-friendly process control strategy. Moreover, an in-line Near-Infrared monitoring method was developed, which offered a real time overview of the moisture level along the granulation process, thus a reliable supervision and control process analytical technology (PAT) tool.

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The preparation procedure of zero magnetic remanence superparamagnetic white paper by means of three-layer membrane configuration (sandwiched structure) is presented. The cellulose acetate fibrous membranes were prepared by electrospinning. The middle membrane layer was magnetically loaded by impregnation with an aqueous ferrofluid of 8 nm magnetic iron oxide nanoparticles colloidally stabilized with a double layer of oleic acid.

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Our recent studies have demonstrated that the antitumor efficacy of doxorubicin (DOX), administered in long-circulating liposomes (LCL), could be considerably improved after its co-encapsulation with curcumin (CURC). Thus, the question addressed within this article is whether LCL-CURC-DOX can be exploited more efficiently than liposomal DOX for future colorectal cancer therapy. Therefore, we investigated the physicochemical and biological properties of LCL-CURC-DOX and the mechanisms of its antitumor activity in C26 murine colon carcinoma in vivo.

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The aim of this work was to develop and validate a NIR method for the quantification of three active ingredients from powder blends. Calibration set formulations were selected based on a D-optimal experimental design with three factors (ibuprofen, paracetamol, caffeine) and five variation levels (80-90-100-110-120%). NIR spectra were recorded in transmittance mode using a rotating sample configuration.

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Cryo-electron microscopy (cryo-EM) can now be used to determine high-resolution structural information on a diverse range of biological specimens. Recent advances have been driven primarily by developments in microscopes and detectors, and through advances in image-processing software. However, for many single-particle cryo-EM projects, major bottlenecks currently remain at the sample-preparation stage; obtaining cryo-EM grids of sufficient quality for high-resolution single-particle analysis can require the careful optimization of many variables.

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Raman scattering and its particular effect, surface-enhanced Raman scattering (SERS), are whole-organism fingerprinting spectroscopic techniques that gain more and more popularity in bacterial detection. In this work, two relevant Gram-positive bacteria species, () and () were characterized based on their Raman and SERS spectral fingerprints. The SERS spectra were used to identify the biochemical structures of the bacterial cell wall.

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The effect of lyoprotectant type and concentration on the stability of freeze-dried prednisolone sodium phosphate-loaded long-circulating liposomes was investigated. Trehalose at a 5:1 carbohydrate to lipid molar ratio proved to be superior in maintaining the structural integrity and the permeability properties of the liposome bilayers, assuring the desired characteristics of the final product: a cake with a porous structure and easy to reconstitute, a similar size to the liposomes before freeze-drying, a high percent of encapsulated drug, and a low residual moisture content. Further on, the study demonstrated the possibility of near-infrared spectroscopy to provide valuable insights for detecting critical changes in acyl chain packing of the liposome bilayer.

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The aim of this study was to apply quality by design (QbD) for pharmaceutical development of enoxaparin sodium microspheres for colon-specific delivery. The Process Parameters (CPPs) and Critical Quality Attributes (CQAs) were identified. A central composite experimental design was used in order to develop the design space of microspheres for colon-specific delivery that have the desired Quality Target Product Profile (QTPP).

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