Publications by authors named "Touraj Ehtezazi"

Oral thrush and throat infections can occur in a wide range of patients. Treatments are available; however, resistance to drugs is a major problem for treating oral and throat infections. Three-dimensional printing (3DP) of fast dissolving oral films (FDFs) of linalool oil may provide an alternative solution.

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Three-dimensional printing (3DP) is rapidly innovating the manufacturing process and provides opportunities that have never been seen before [...

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Recent clinical studies have revealed that the serum levels of toxic hydrophobic bile acids (deoxy cholic acid, lithocholic acid [LCA], and glycoursodeoxycholic acid) are significantly higher in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) when compared to control subjects. The elevated serum bile acids may be the result of hepatic peroxisomal dysfunction. Circulating hydrophobic bile acids are able to disrupt the blood-brain barrier and promote the formation of amyloid-β plaques through enhancing the oxidation of docosahexaenoic acid.

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Three-dimensional printing (3DP) allows production of novel fast dissolving oral films (FDFs). However, mechanical properties of the films may not be desirable when certain excipients are used. This work investigated whether adding chitosan micro-ribbons or cellulose microfibres will achieve desired FDFs by fused deposition modelling 3DP.

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Introduction: Serious COVID-19 respiratory problems start when the virus reaches the alveolar level, where type II cells get infected and die. Therefore, virus inhibition at the alveolar level would help preventing these respiratory complications.

Method: A literature search was conducted to collect physicochemical properties of small molecule compounds that could be used for the COVID-19 treatment.

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The prevalence of neurological/neurodegenerative diseases, such as Alzheimer's disease is known to be increasing due to an aging population and is anticipated to further grow in the decades ahead. The treatment of brain diseases is challenging partly due to the inaccessibility of therapeutic agents to the brain. An increasingly important observation is that the physiology of the brain alters during many brain diseases, and aging adds even more to the complexity of the disease.

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Introduction The objectives were to characterise the particle size distribution of aerosols generated by standard dental aerosol generating procedures (AGPs) and to assess the impact of aerosol-management interventions on 'fallow time'. Interventions included combinations of high-volume intraoral suction (HVS[IO]), high-volume extraoral suction (HVS[EO]) and an air cleaning system (ACS).Method A sequence of six AGPs were performed on a phantom head.

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This study investigated whether the inclusion of a matrix metalloproteinase-9 (MMP-9) responsive sequence in self-assembled peptide-based brain-targeting nanoparticles (NPs) would enhance the blood-brain barrier (BBB) penetration when MMP-9 levels are elevated both in the brain and blood circulation. Brain-targeting peptides were conjugated at the N-terminus to MMP-9-responsive peptides, and these were conjugated at the N-terminus to lipid moiety (cholesteryl chloroformate or palmitic acid). Two constructs did not have MMP-9-responsive peptides.

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Latent and active levels of cerebral matrix metalloproteinase 9 (MMP-9) are elevated in neurological diseases and brain injuries, contributing to neurological damage and poor clinical outcomes. This study aimed developing peptide-based nanoparticles with ability to cross the blood-brain-barrier (BBB) and inhibit MMP-9. Three amphiphilic peptides were synthesised containing brain-targeting ligands (HAIYPRH or CKAPETALC) conjugated with MMP-9 inhibiting peptide (CTTHWGFTLC) linked by glycine (spacer) at the N-terminus, and the peptide sequences were conjugated at the N- terminus to cholesterol.

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Background: Inkjet method has been used to produce nano-sized liposomes with a uniform size distribution. However, following the production of liposomes by inkjet method, the solvent residue in the product could have a significant effect on the properties of the final liposomes.

Objective: This research paper aimed to find a suitable method to remove ethanol content and to study its effect on the properties of the final liposomal suspension.

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3D printing technique has been utilised to develop novel and complex drug delivery systems that are almost impossible to produce by employing conventional formulation techniques. For example, this technique may be employed to produce tablets or Fast Dissolving oral Films (FDFs) with multilayers of active ingredients, which are personalised to patient's needs. In this article, we compared the production of FDFs by 3D printing to conventional methods such as solvent casting.

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Objective: To investigate the effect of formulation parameters on the preparation of transfersomes as sustained-release delivery systems for lidocaine and to develop and validate a new high-performance liquid chromatography (HPLC) method for analysis.

Method: Taguchi design of experiment (DOE) was used to optimise lidocaine-loaded transfersomes in terms of phospholipid, edge activator (EA) and phospholipid : EA ratio. Transfersomes were characterised for size, polydispersity index (PDI), charge and entrapment efficiency (%EE).

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Understanding the effect of surfactant properties is critical when designing vesicular delivery systems. This review evaluates previous studies to explain the influence of surfactant properties on the behavior of lipid vesicular systems, specifically their size, charge, stability, entrapment efficiency, pharmacokinetics, and pharmacodynamics. Generally, the size of vesicles decreases by increasing the surfactant concentration, carbon chain length, the hydrophilicity of the surfactant head group, and the hydrophilic-lipophilic balance.

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Fast-dissolving oral films (FDFs) provide an alternative approach to increase consumer acceptance by advantage of rapid dissolution and administration without water. Usually, FDFs require taste-masking agents. However, inclusion of these excipients could make developing the formulation a challenging task.

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The application of the inkjet method to pharmaceutical products is promising. To make this realistic, not only does the throughput of this method need to be increased, but also the components should be inert to pharmaceutical preparations. We present designs of glass-based inkjet devices that are capable of producing droplets at high rates.

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Delivery of medication to the neonatal lung using current methods is inefficient. Aerosols offer one way to improve delivery to small airways. In this in vitro work, aerosol delivery by using a micropump or a rotary valve has been evaluated in a model of the neonatal setting with a pressurised metered dose inhaler plus spacer outside of the inspiratory limb.

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In this paper recent patents in pressurised metered dose inhalers have been reviewed. The patents are related to novel valves, dose-counters, formulations, add-on devices, reduction of propellant leakage and inkjet technology. Recently patented dose-counters provide mechanisms that are less susceptible to inaccuracy, and are battery-less electronic dose-counters with the help of miniature electromechanical generators.

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Background: The aim of this study was to evaluate the compaction behavior of a model two-component amorphous spray-dried dispersion system compared with the unprocessed excipients, using simulated rotary tablet press production conditions.

Method: In this study, the stabilizing polymer, hypromellose acetate succinate (HPMCAS), was solubilized and spray dried with and without sodium lauryl sulfate (SLS). The impact of compression force and speed on the tabletting process was quantified by means of tablet tensile strength, compaction energy, and Heckel analysis.

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Entrainment and de-aggregation of aerosol particles from dry powder inhalers (DPIs) is achieved by a forceful inhalation from the device by the patient and by the airflow resistance built into the device. The aerodynamic shear stress imposed by the upper airway also plays an important role in the de-aggregation process. In this study the effect of device airflow resistance on the upper airway shape is determined.

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Although it is likely that the upper airway is a major factor in the large inter- and intra-subject variation in deposition of inhaled drug aerosols in the lung, data on the configuration of the upper airway during inhalation is sparse. We have developed a unique method, using magnetic resonance imaging, to reconstruct the upper airway in three dimensions during inhalation from aerosol devices used to deliver medication to patients with asthma, chronic obstructive pulmonary disease, and cystic fibrosis. Ten healthy adults were imaged while inhaling from a pressurized metered dose inhaler (pMDI), a spacer used with pMDI (spacer), and a high-resistance dry powder inhaler, the Turbuhaler (DPI).

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The optimization of DNA-cationic polymer complexation is crucial for nonviral gene delivery. Although physicochemical characterization of the interaction between DNA and cationic polymers has recently attracted more attention in the nonviral DNA delivery field, the literature on the effect of varying polycation charge density on DNA-cationic polymer complexation is still scarce. Thus, the aim of this study was to systematically assess the influence of the degree of ionization of a weak cationic polyelectrolyte (poly[2-(dimethylamino)ethyl methacrylate] or DMAEMA homopolymer) on its ability to form complexes with DNA.

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