Introduction: Methadone hydrochloride (MDN) is an effective pharmacological substitution treatment for opioids dependence, adopted in different countries as methadone maintenance treatment (MMT) programmes. However, MDN can exacerbate the addiction problem if it is abused and injected intravenously, and the frequent visits to the MMT centres can reduce patient compliance. The overall aim of this study is to develop a novel extended-release capsule of MDN using the sol-gel silica (SGS) technique that has the potential to counteract medication-tampering techniques and associated health risks and reduce the frequent visits to MMT centres. Methods: For MDN recrystallisation, a closed container method (CCM) and hot-stage method (HSM) were conducted, and MDN crystals were characterised using the polarised light microscope (PLM). MDN crystal thickness was determined by scanning electron microscopy (SEM) and confocal microscopy (CM) to establish a relationship between MDN crystals thickness and their birefringence colours using the Michel-Levy Birefringence Colour Chart. The experimental series was continued to produce novel silica-based MDN formulations A and B capsules by adding MDN powder at the end and beginning of the SGS process, respectively. The silica-based MDN formulations were characterised by Fourier transform infrared (FT-IR), SEM, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), PLM and mean grey value (MGV) analyses. The in vitro release studies (n=3) for the silica-based MDN formulations and pure MDN capsules were conducted in a phosphate buffer solution (pH= 7.2) for 7 days. Stability studies were conducted for 1 month by keeping the silica-based MDN capsules under 25°C and 57% RH. Results: The optimal method to produce large numbers of MDN crystals was the CCM, and MDN crystals were characterised as diamond shaped with an intrinsic angle of 62o. The SEM surpassed the CM in measuring MDN crystal thickness, and Mann-Whitney U Test showed statistically significant differences between SEM and confocal thickness measurements (U= 1283, p < 0.05) as the SEM exhibited thinner diamond crystals (6.62 ± 2.9 µm) than the CM measurements (9.6 ± 4.6µm). According to the Michel-Levey birefringence colour chart (using the SEM mean thickness of MDN crystals and their retardation value of 428 nm), most of MDN crystals demonstrated a yellow colour. The FT-IR, SEM, DSC, MGV and PLM analyses of both silica-based MDN formulations revealed that MDN was successfully incorporated inside the silica network producing amorphous material (with no appearance of the melting peak of pure MDN at 233.4°C) with evidence of no physical or chemical interaction between sol-gel silica and MDN. However, the TGA analysis revealed a significantly greater amount of MDN was loaded inside the silica-based MDN formulation B compared to A (t = 2.80, p = 0.009, n=6), as 28.3 ± 0.6 mg of MDN was loaded in the former while 25.6 ± 0.7 mg in the latter. In addition, the silica-based MDN formulation B released 10% more MDN after 7 days than formulation A, and both formulations were stable when stored for 1 month under 57% RH and 25°C. Conclusion: The novel combined use of SEM and PLM techniques shows a potential for the identification of MDN in forensic science as it established a range of birefringence colours of MDN crystals. Moreover, the new silica-based MDN formulation B can help to deter MDN abuse and increase patient adherence to MMT due to its potential to sustain MDN release and reduce the frequent visits to MDN treatment centres.
In this work, the nano particles of Na-A zeolite were synthesized by sol –gel method. The samples were characterized by X-ray diffraction (XRD), X-ray luorescence (XRF), Surface area and pore volume, Atomic Force Microscope (AFM) and Fourier Transform Infrared Spectroscopy (FTIR). Results show that the nano A zeolite is with average crystal size is 74.77 nm., Si/Al ratio 1.03, BET surface area was 581.211m2/g and the pore volume for NaA was found equal to 0.355cm3/g.
Manganese-zinc ferrite MnxZn1-xFe2O4 (MnZnF) powder was prepared using the sol-gel method. The morphological, structural, and magnetic properties of MnZnF powder were studied using X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive X-ray (EDX), field emission-scanning electron microscopes (FE-SEM), and vibrating sample magnetometers (VSM). The XRD results showed that the MnxZn1-xFe2O4 that was formed had a trigonal crystalline structure. AFM results showed that the average diameter of Manganese-Zinc Ferrite is 55.35 nm, indicating that the sample has a nanostructure dimension. The EDX spectrum revealed the presence of transition metals (Mn, Fe, Zn, and O) in Mang
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CuO nanoparticles were synthesized in two different ways, firstly by precipitation method using copper acetate monohydrate Cu(CO2CH13)2·H2O, glacial acetic acid (CH3COOH) and sodium hydroxide(NaOH), and secondly by sol-gel method using copper chloride(CuCl2), sodium hydroxide (NaOH) and ethanol (C2H6O). Results of scanning electron microscopy (SEM) showed that different CuO nanostructures (spherical and Reef) can be formed using precipitation and sol- gel process, respectively, at which the particle size was found to be less than 2 µm. X-ray diffraction (XRD)manifested that the pure synthesized powder has no inclusions that may exist during preparations. XRD result
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Powder of silver nanoparticles was prepared by Sol - Gel method successfully using silver nitrate , (AgNO3) gesture is added to sodium citrate (C6H5O7Na3) as a reducing agent and by using Magnetic Stirrer to mix the solutions and heated then using centrifuge machine to separate the silver nanoparticles from solution .It is then dried in an oven at a temperature 40oC for 24 hours. Structure characteristics was studied , the synthetic silver powder was prepared through the use of an (XRD). Results showed the composition of silver nanoparticles is a (fcc) and a constant lattice (4.086 ± 0.006 Å) by comparing it with standard tables (JCPDS) which is found perfectly matched to file with a number 04-0783, which
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The prepared nanostructure SiO2 thin films were densified by two techniques (conventional and Diode Pumped Solid State Laser (DPSS) (532 nm). X-ray diffraction (XRD), Field Emission Scanning electron microscopy (FESEM), and Atomic Force Microscope (AFM) technique were used to analyze the samples. XRD results showed that the structure of SiO2 thin films was amorphous for both Oven and Laser densification. FESEM and AFM images revealed that the shape of nano silica is spherical and the particle size is in nano range. The small particle size of SiO2 thin film densified by DPSS Laser was (26 nm) , while the smallest particle size of SiO2 thin film densified by Oven was (111 nm).
In this study, titanium dioxide (TiO2 (are synthesized by sol– gel simple method. Thin films of sol, gel, and sol- gel on relatively flat glass substrates are applied with Spin coating technique with multilayers. The optical and morphological properties (studied using AFM) of TiO2 layers show good properties, with particles diameters less than 4 nm for all prepared samples and have maximum length 62 nm for TiO2 gel thin films of three layers. The results show low roughness values for all films especially for 4 layers sol (8.37nm), which improve the application in dye sensitive solar cell (DSSc) .
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