Displaying publications 1 - 20 of 35 in total

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  1. Development of solid dispersion systems of dapivirine to enhance its solubility
    Gorajana A, Ying CC, Shuang Y, Fong P, Tan Z, Gupta J, et al.
    Curr Drug Deliv, 2013 Jun;10(3):309-16.
    PMID: 23360246
    Dapivirine, formerly known as TMC 120, is a poorly-water soluble anti-HIV drug, currently being developed as a vaginal microbicide. The clinical use of this drug has been limited due to its poor solubility. The aim of this study was to design solid dispersion systems of Dapivirine to improve its solubility. Solid dispersions were prepared by solvent and fusion methods. Dapivirine release from the solid dispersion system was determined by conducting in-vitro dissolution studies. The physicochemical characteristics of the drug and its formulation were studied using Differential Scanning Calorimetry (DSC), powder X-ray Diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). A significant improvement in drug dissolution rate was observed with the solid dispersion systems. XRD, SEM and DSC results indicated the transformation of pure Dapivirine which exists in crystalline form into an amorphous form in selected solid dispersion formulations. FTIR and HPLC analysis confirmed the absence of drug-excipient interactions. Solid dispersion systems can be used to improve the dissolution rate of Dapivirine. This improvement could be attributed to the reduction or absence of drug crystallinity, existence of drug particles in an amorphous form and improved wettability of the drug.
    Matched MeSH terms: Powder Diffraction
  2. Arginine Complexes with Simvastatin: Apparent Solubility, In Vitro Dissolution and Solid State Characterization
    Affandi MMRMM, Tripathy M, Majeed ABA
    Curr Drug Deliv, 2018;15(1):77-86.
    PMID: 28322162 DOI: 10.2174/1567201814666170320144259
    BACKGROUND: Categorized as a Biopharmaceutics Classification System (BCS) Class II drugs, statin exhibit low aqueous solubility and bioavailability thus presenting an obstacle and great challenge to formulation researchers. This paper describes a de novo approach to enhance the aqueous solubility of one of the most commonly prescribed statins i.e., simvastatin (SMV) by forming a complex (SMV-ARG) with cosolute arginine (ARG).

    METHODS: The complex has been characterized for its apparent solubility and in vitro dissolution. The solid state characterization has been carried out using Fourier Transform Infra-Red (FTIR) Spectroscopy, Elemental Analysis, X-Ray Powder Diffraction (XRD), Differential Scanning Calorimetry (DSC) analysis, Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM).

    RESULTS: Simvastatin-Arginine (SMV-ARG) complex exhibited massive solubility enhancement by 12,000 fold and significant improvement in both acidic and alkaline dissolution media. A conversion of coherent crystalline to non-coherent pattern, and certain extent of amorphization in SMV-ARG complex, fully justifies the enhanced solubility, and hence the dissolution profile.

    CONCLUSION: The present study provides a significant evidence that ARG molecules are capable to form a complex with small molecules and increase their aqueous solubility which prove to be beneficial in drug formulation and development.

    Matched MeSH terms: Powder Diffraction
  3. Development and characterization of lecithin stabilized glibenclamide nanocrystals for enhanced solubility and drug delivery
    Kumar BS, Saraswathi R, Kumar KV, Jha SK, Venkates DP, Dhanaraj SA
    Drug Deliv, 2014 May;21(3):173-84.
    PMID: 24102185 DOI: 10.3109/10717544.2013.840690
    Novel LNCs (lipid nanocrystals) were developed with an aim to improve the solubility, stability and targeting efficiency of the model drug glibenclamide (GLB). PEG 20000, Tween 80 and soybean lecithin were used as polymer, surfactant and complexing agent, respectively. GLB nanocrystals (NCs) were prepared by precipitation process and complexed using hot and cold melt technique. The LNCs were evaluated by drug loading, saturation solubility (SL), optical clarity, in vitro dissolution, solid state characterization, in vivo and stability analysis. LNCs exhibited a threefold increase in SL and a higher dissolution rate than GLB. The percentage dissolution efficiency was found to decrease with increase in PEG 20000. The average particle size was in the range of 155-842 nm and zeta potential values tend to increase after complexation. X-ray powder diffractometry and differential scanning calorimetry results proved the crystallinity prevailed in the samples. Spherical shaped particles (<1000 nm) with a lipid coat on the surface were observed in scanning electron microscopy analysis. Fourier transform infrared results proved the absence of interaction between drug and polymer and stability study findings proved that LNCs were stable. In vivo study findings showed a decrease in drug concentration to pancreas in male Wistar rats. It can be concluded that LNCs are could offer enhanced solubility, dissolution rate and stability for poorly water soluble drugs. The targeting efficiency of LNCs was decreased and further membrane permeability studies ought to be carried out.
    Matched MeSH terms: Powder Diffraction
  4. Fulltext Berberine nanoparticles with enhanced in vitro bioavailability: characterization and antimicrobial activity
    Sahibzada MUK, Sadiq A, Faidah HS, Khurram M, Amin MU, Haseeb A, et al.
    Drug Des Devel Ther, 2018;12:303-312.
    PMID: 29491706 DOI: 10.2147/DDDT.S156123
    BACKGROUND: Berberine is an isoquinoline alkaloid widely used in Ayurveda and traditional Chinese medicine to treat illnesses such as hypertension and inflammatory conditions, and as an anticancer and hepato-protective agent. Berberine has low oral bioavailability due to poor aqueous solubility and insufficient dissolution rate, which can reduce the efficacy of drugs taken orally. In this study, evaporative precipitation of nanosuspension (EPN) and anti-solvent precipitation with a syringe pump (APSP) were used to address the problems of solubility, dissolution rate and bioavailability of berberine.

    METHODS: Semi-crystalline nanoparticles (NPs) of 90-110 nm diameter for APSP and 65-75 nm diameter for EPN were prepared and then characterized using differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD). Thereafter, drug content solubility and dissolution studies were undertaken. Berberine and its NPs were evaluated for their antibacterial activity.

    RESULTS: The results indicate that the NPs have significantly increased solubility and dissolution rate due to conversion of the crystalline structure to a semi-crystalline form.

    CONCLUSION: Berberine NPs produced by both APSP and EPN methods have shown promising activities against Gram-positive and Gram-negative bacteria, and yeasts, with NPs prepared through the EPN method showing superior results compared to those made with the APSP method and the unprocessed drug.

    Matched MeSH terms: Powder Diffraction
  5. Design and development of dry powder sulfobutylether-β-cyclodextrin complex for pulmonary delivery of fisetin
    Mohtar N, Taylor KM, Sheikh K, Somavarapu S
    Eur J Pharm Biopharm, 2017 Apr;113:1-10.
    PMID: 27916704 DOI: 10.1016/j.ejpb.2016.11.036
    This study has investigated complexation of fisetin, a natural flavonoid, with three types of cyclodextrins to improve its solubility. Sulfobutylether-β-cyclodextrin (SBE-β-CD) showed the highest complexation efficiency while maintaining the in vitro antioxidant activity of fisetin. Addition of 20%v/v ethanol in water improved the amount of solubilized fisetin in the complex 5.9-fold compared to the system containing water alone. Spray drying of fisetin-SBE-β-CD complex solution in the presence of ethanol produced a dry powder with improved aerosolization properties when delivered from a dry powder inhaler, indicated by a 2-fold increase in the fine particle fraction (FPF) compared to the powder produced from the complex solution containing water alone. The pitted morphological surface of these particles suggested a more hollow internal structure, indicating a lighter and less dense powder. Incorporation of 20%w/w leucine improved the particle size distribution of the powder and further increased the FPF by 2.3-fold. This formulation also showed an EC50 value equivalent to fisetin alone in the A549 cell line. In conclusion, an inhalable dry powder containing fisetin-SBE-β-CD complex was successfully engineered with an improved aqueous solubility of fisetin. The dry powder may be useful to deliver high amounts of fisetin to the deep lung region for therapeutic purposes.
    Matched MeSH terms: Powder Diffraction
  6. Fulltext Reflection and transmission coefficient of yttrium iron garnet filled polyvinylidene fluoride composite using rectangular waveguide at microwave frequencies
    Soleimani H, Abbas Z, Yahya N, Shameli K, Soleimani H, Shabanzadeh P
    Int J Mol Sci, 2012;13(7):8540-8.
    PMID: 22942718 DOI: 10.3390/ijms13078540
    The sol-gel method was carried out to synthesize nanosized Yttrium Iron Garnet (YIG). The nanomaterials with ferrite structure were heat-treated at different temperatures from 500 to 1000 °C. The phase identification, morphology and functional groups of the prepared samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. The YIG ferrite nanopowder was composited with polyvinylidene fluoride (PVDF) by a solution casting method. The magnitudes of reflection and transmission coefficients of PVDF/YIG containing 6, 10 and 13% YIG, respectively, were measured using rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in X-band frequencies. The results indicate that the presence of YIG in polymer composites causes an increase in reflection coefficient and decrease in transmission coefficient of the polymer.
    Matched MeSH terms: Powder Diffraction
  7. Fulltext Synthesis of talc/Fe3O4 magnetic nanocomposites using chemical co-precipitation method
    Kalantari K, Bin Ahmad M, Shameli K, Khandanlou R
    Int J Nanomedicine, 2013;8:1817-23.
    PMID: 23696700 DOI: 10.2147/IJN.S43693
    The aim of this research was to synthesize and develop a new method for the preparation of iron oxide (Fe(3)O(4)) nanoparticles on talc layers using an environmentally friendly process. The Fe(3)O(4) magnetic nanoparticles were synthesized using the chemical co-precipitation method on the exterior surface layer of talc mineral as a solid substrate. Ferric chloride, ferrous chloride, and sodium hydroxide were used as the Fe(3)O(4) precursor and reducing agent in talc. The talc was suspended in deionized water, and then ferrous and ferric ions were added to this solution and stirred. After the absorption of ions on the exterior surface of talc layers, the ions were reduced with sodium hydroxide. The reaction was carried out under a nonoxidizing oxygen-free environment. There were not many changes in the interlamellar space limits (d-spacing = 0.94-0.93 nm); therefore, Fe(3)O(4) nanoparticles formed on the exterior surface of talc, with an average size of 1.95-2.59 nm in diameter. Nanoparticles were characterized using different methods, including powder X-ray diffraction, transmission electron microscopy, emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. These talc/Fe(3)O(4) nanocomposites may have potential applications in the chemical and biological industries.
    Matched MeSH terms: Powder Diffraction
  8. Fulltext Preparation and controlled-release studies of a protocatechuic acid-magnesium/aluminum-layered double hydroxide nanocomposite
    Barahuie F, Hussein MZ, Hussein-Al-Ali SH, Arulselvan P, Fakurazi S, Zainal Z
    Int J Nanomedicine, 2013;8:1975-87.
    PMID: 23737666 DOI: 10.2147/IJN.S42718
    In the study reported here, magnesium/aluminum (Mg/Al)-layered double hydroxide (LDH) was intercalated with an anticancer drug, protocatechuic acid, using ion-exchange and direct coprecipitation methods, with the resultant products labeled according to the method used to produce them: "PANE" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the ion-exchange method) and "PAND" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the direct method), respectively. Powder X-ray diffraction and Fourier transform infrared spectroscopy confirmed the intercalation of protocatechuic acid into the inter-galleries of Mg/Al-LDH. The protocatechuic acid between the interlayers of PANE and PAND was found to be a monolayer, with an angle from the z-axis of 8° for PANE and 15° for PAND. Thermogravimetric and differential thermogravimetric analysis results revealed that the thermal stability of protocatechuic acid was markedly enhanced upon intercalation. The loading of protocatechuic acid in PANE and PAND was estimated to be about 24.5% and 27.5% (w/w), respectively. The in vitro release study of protocatechuic acid from PANE and PAND in phosphate-buffered saline at pH 7.4, 5.3, and 4.8 revealed that the nanocomposites had a sustained release property. After 72 hours incubation of PANE and PAND with MCF-7 human breast cancer and HeLa human cervical cancer cell lines, it was found that the nanocomposites had suppressed the growth of these cancer cells, with a half maximal inhibitory concentration of 35.6 μg/mL for PANE and 36.0 μg/mL for PAND for MCF-7 cells, and 19.8 μg/mL for PANE and 30.3 μg/mL for PAND for HeLa cells. No half maximal inhibitory concentration for either nanocomposite was found for 3T3 cells.
    Matched MeSH terms: Powder Diffraction
  9. Fulltext Controlled-release formulation of antihistamine based on cetirizine zinc-layered hydroxide nanocomposites and its effect on histamine release from basophilic leukemia (RBL-2H3) cells
    Hasan S, Al Ali H, Al-Qubaisi M, Zobir Hussein M, Ismail M, Zainal Z, et al.
    Int J Nanomedicine, 2012;7:3351-63.
    PMID: 22848164 DOI: 10.2147/IJN.S30809
    A controlled-release formulation of an antihistamine, cetirizine, was synthesized using zinc-layered hydroxide as the host and cetirizine as the guest. The resulting well-ordered nanolayered structure, a cetirizine nanocomposite "CETN," had a basal spacing of 33.9 Å, averaged from six harmonics observed from X-ray diffraction. The guest, cetirizine, was arranged in a horizontal bilayer between the zinc-layered hydroxide (ZLH) inorganic interlayers. Fourier transform infrared spectroscopy studies indicated that the intercalation takes place without major change in the structure of the guest and that the thermal stability of the guest in the nanocomposites is markedly enhanced. The loading of the guest in the nanocomposites was estimated to be about 49.4% (w/w). The release study showed that about 96% of the guest could be released in 80 hours by phosphate buffer solution at pH 7.4 compared with about 97% in 73 hours at pH 4.8. It was found that release was governed by pseudo-second order kinetics. Release of histamine from rat basophilic leukemia cells was found to be more sensitive to the intercalated cetirizine in the CETN compared with its free counterpart, with inhibition of 56% and 29%, respectively, at 62.5 ng/mL. The cytotoxicity assay toward Chang liver cells line show the IC₅₀ for CETN and ZLH are 617 and 670 μg/mL, respectively.
    Matched MeSH terms: Powder Diffraction
  10. Fulltext Controlled release and angiotensin-converting enzyme inhibition properties of an antihypertensive drug based on a perindopril erbumine-layered double hydroxide nanocomposite
    Hussein Al Ali SH, Al-Qubaisi M, Hussein MZ, Ismail M, Zainal Z, Hakim MN
    Int J Nanomedicine, 2012;7:2129-41.
    PMID: 22619549 DOI: 10.2147/IJN.S30461
    The intercalation of perindopril erbumine into Zn/Al-NO(3)-layered double hydroxide resulted in the formation of a host-guest type of material. By virtue of the ion-exchange properties of layered double hydroxide, perindopril erbumine was released in a sustained manner. Therefore, this intercalated material can be used as a controlled-release formulation.
    Matched MeSH terms: Powder Diffraction
  11. Fulltext Synthesis and characterization of silver/montmorillonite/chitosan bionanocomposites by chemical reduction method and their antibacterial activity
    Shameli K, Bin Ahmad M, Zargar M, Yunus WM, Ibrahim NA, Shabanzadeh P, et al.
    Int J Nanomedicine, 2011;6:271-84.
    PMID: 21499424 DOI: 10.2147/IJN.S16043
    Silver nanoparticles (AgNPs) of a small size were successfully synthesized using the wet chemical reduction method into the lamellar space layer of montmorillonite/chitosan (MMT/Cts) as an organomodified mineral solid support in the absence of any heat treatment. AgNO3, MMT, Cts, and NaBH4 were used as the silver precursor, the solid support, the natural polymeric stabilizer, and the chemical reduction agent, respectively. MMT was suspended in aqueous AgNO3/Cts solution. The interlamellar space limits were changed (d-spacing = 1.24-1.54 nm); therefore, AgNPs formed on the interlayer and external surface of MMT/Cts with d-average = 6.28-9.84 nm diameter. Characterizations were done using different methods, ie, ultraviolet-visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence spectrometry, and Fourier transform infrared spectroscopy. Silver/montmorillonite/chitosan bionanocomposite (Ag/MMT/Cts BNC) systems were examined. The antibacterial activity of AgNPs in MMT/Cts was investigated against Gram-positive bacteria, ie, Staphylococcus aureus and methicillin-resistant S. aureus and Gram-negative bacteria, ie, Escherichia coli, E. coli O157:H7, and Pseudomonas aeruginosa by the disc diffusion method using Mueller Hinton agar at different sizes of AgNPs. All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity. These results show that Ag/MMT/Cts BNCs can be useful in different biological research and biomedical applications, including surgical devices and drug delivery vehicles.
    Matched MeSH terms: Powder Diffraction
  12. Fulltext Development of antiproliferative nanohybrid compound with controlled release property using ellagic acid as the active agent
    Hussein MZ, Al Ali SH, Zainal Z, Hakim MN
    Int J Nanomedicine, 2011;6:1373-83.
    PMID: 21796241 DOI: 10.2147/IJN.S21567
    An ellagic acid (EA)-zinc layered hydroxide (ZLH) nanohybrid (EAN) was synthesized under a nonaqueous environment using EA and zinc oxide (ZnO) as the precursors. Powder X-ray diffraction showed that the basal spacing of the nanohybrid was 10.4 Å, resulting in the spatial orientation of EA molecules between the interlayers of 22.5° from z-axis with two negative charges at 8,8' position of the molecules pointed toward the ZLH interlayers. FTIR study showed that the intercalated EA spectral feature is generally similar to that of EA, but with bands slightly shifted. This indicates that some chemical bonding of EA presence between the nanohybrid interlayers was slightly changed, due to the formation of host-guest interaction. The nanohybrid is of mesopores type with 58.8% drug loading and enhanced thermal stability. The release of the drug active, EA from the nanohybrid was found to be sustained and therefore has good potential to be used as a drug controlled-release formulation. In vitro bioassay study showed that the EAN has a mild effect on the hepatocytes cells, similar to its counterpart, free EA.
    Matched MeSH terms: Powder Diffraction
  13. Fulltext Synthesis of silver nanoparticles in montmorillonite and their antibacterial behavior
    Shameli K, Ahmad MB, Zargar M, Yunus WM, Rustaiyan A, Ibrahim NA
    Int J Nanomedicine, 2011;6:581-90.
    PMID: 21674015 DOI: 10.2147/IJN.S17112
    Silver nanoparticles (Ag NPs) were synthesized by the chemical reducing method in the external and interlamellar space of montmorillonite (MMT) as a solid support at room temperature. AgNO(3) and NaBH(4) were used as a silver precursor and reducing agent, respectively. The most favorable experimental conditions for synthesizing Ag NPs in the MMT are described in terms of the initial concentration of AgNO(3). The interlamellar space limits changed little (d-spacing = 1.24-1.47 nm); therefore, Ag NPs formed on the MMT suspension with d-average = 4.19-8.53 nm diameter. The Ag/MMT nanocomposites (NCs), formed from AgNO(3)/MMT suspension, were characterizations with different instruments, for example UV-visible, PXRD, TEM, SEM, EDXRF, FT-IR, and ICP-OES analyzer. The antibacterial activity of different sizes of Ag NPs in MMT were investigated against Gram-positive, ie, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) and Gram-negative bacteria, ie, Escherichia coli, Escherichia coli O157:H7, and Klebsiella pneumoniae, by the disk diffusion method using Mueller-Hinton agar (MHA). The smaller Ag NPs were found to have significantly higher antibacterial activity. These results showed that Ag NPs can be used as effective growth inhibitors in different biological systems, making them applicable to medical applications.
    Matched MeSH terms: Powder Diffraction
  14. Fulltext Synthesis and characterization of silver/talc nanocomposites using the wet chemical reduction method
    Shameli K, Ahmad MB, Yunus WZ, Ibrahim NA, Darroudi M
    Int J Nanomedicine, 2010;5:743-51.
    PMID: 21042420 DOI: 10.2147/IJN.S13227
    In this study, silver nanoparticles (Ag-NPs) were synthesized using the wet chemical reduction method on the external surface layer of talc mineral as a solid support. Silver nitrate and sodium borohydride were used as the silver precursor and reducing agent in talc. The talc was suspended in aqueous AgNO(3) solution. After the absorption of Ag(+) on the surface, the ions were reduced with NaBH(4). The interlamellar space limits were without many changes (d(s) = 9.34-9.19 A(º)); therefore, Ag-NPs formed on the exterior surface of talc, with d(ave) = 7.60-13.11 nm in diameter. The properties of Ag/talc nanocomposites (Ag/talc-NCs) and the diameters of the Ag-NPs prepared in this way depended on the primary AgNO(3) concentration. The prepared Ag-NPs were characterized by ultraviolet-visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared. These Ag/talc-NCs may have potential applications in the chemical and biological industries.
    Matched MeSH terms: Powder Diffraction
  15. Fulltext Fabrication of silver nanoparticles doped in the zeolite framework and antibacterial activity
    Shameli K, Ahmad MB, Zargar M, Yunus WM, Ibrahim NA
    Int J Nanomedicine, 2011;6:331-41.
    PMID: 21383858 DOI: 10.2147/IJN.S16964
    Using the chemical reduction method, silver nanoparticles (Ag NPs) were effectively synthesized into the zeolite framework in the absence of any heat treatment. Zeolite, silver nitrate, and sodium borohydride were used as an inorganic solid support, a silver precursor, and a chemical reduction agent, respectively. Silver ions were introduced into the porous zeolite lattice by an ion-exchange path. After the reduction process, Ag NPs formed in the zeolite framework, with a mean diameter of about 2.12-3.11 nm. The most favorable experimental condition for the synthesis of Ag/zeolite nanocomposites (NCs) is described in terms of the initial concentration of AgNO(3). The Ag/zeolite NCs were characterized by ultraviolet-visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, and Fourier transform infrared. The results show that Ag NPs form a spherical shape with uniform homogeneity in the particle size. The antibacterial activity of Ag NPs in zeolites was investigated against Gram-negative bacteria (ie, Escherichia coli and Shigella dysentriae) and Gram-positive bacteria (ie, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus) by disk diffusion method using Mueller-Hinton agar at different sizes of Ag NPs. All of the synthesized Ag/zeolite NCs were found to have antibacterial activity. These results show that Ag NPs in the zeolite framework can be useful in different biological research and biomedical applications.
    Matched MeSH terms: Powder Diffraction
  16. Fulltext Green synthesis of silver/montmorillonite/chitosan bionanocomposites using the UV irradiation method and evaluation of antibacterial activity
    Shameli K, Ahmad MB, Yunus WM, Rustaiyan A, Ibrahim NA, Zargar M, et al.
    Int J Nanomedicine, 2010 Oct 22;5:875-87.
    PMID: 21116328 DOI: 10.2147/IJN.S13632
    In this study, silver nanoparticles (Ag-NPs) were synthesized using a green physical synthetic route into the lamellar space of montmorillonite (MMT)/chitosan (Cts) utilizing the ultraviolet (UV) irradiation reduction method in the absence of any reducing agent or heat treatment. Cts, MMT, and AgNO(3) were used as the natural polymeric stabilizer, solid support, and silver precursor, respectively. The properties of Ag/MMT/Cts bionanocomposites (BNCs) were studied as the function of UV irradiation times. UV irradiation disintegrated the Ag-NPs into smaller sizes until a relatively stable size and size distribution were achieved. Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy. The antibacterial activity of Ag-NPs in MMT/Cts was investigated against Gram-positive bacteria, ie, Staphylococcus aureus and methicillin-resistant S. aureus and Gram-negative bacteria (ie, Escherichia coli) by the disk diffusion method on Muller-Hinton Agar at different sizes of Ag-NPs. All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity. These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.
    Matched MeSH terms: Powder Diffraction
  17. Fulltext Antimicrobial activities of silver nanoparticles bio-synthesized from diatom Amphora sp.
    Tevan, R., Govindaraju, Mugilan, Jayakumar, Saravanan, Govindan, Natanamurugaraj, Mohd Hasbi Ab. Rahim, Maniam, Gaanty Pragas, et al.
    Journal of Engineering and Science Research, 2017;1(2):176-184.
    MyJurnal
    A biological method was employed to synthesize silver nanoparticles through marine diatom Amphora sp. Antimicrobial efficacy test against different pathogenic bacteria were performed through synthesized silver nanoparticles. The physio-chemical properties of synthesized silver nanoparticles were studied using analytical techniques such as UV-Vis spectrophotometer, Field Emission Scanning Electron Microscopy (FESEM), EnergyDispersive X-ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Powder Diffraction (XRD). UV-Vis color intensity study and higher magnification of the Field Emission Scanning Electron Microscopy image showed the synthesized silver nanoparticles were rod shaped with a size range from 42 nm to 46 nm. The synthesized nanoparticles exhibited antibacterial activities in varying magnitudes. About 10 mg/ml of silver nanoparticles were able to inhibit the growth of gram-negative bacteria while gram-positive bacteria were resistant towards similar concentrations of silver nanoparticles.
    Matched MeSH terms: Powder Diffraction
  18. Fulltext Rietveld quantitative phase analysis of non-stoichiometric cordierite synthesised from mainly talc and kaolin: effect of sintering temperature
    Banjuraizah Johar, Hasmaliza Mohamad, Zainal Arifin Ahmad
    Journal of Nuclear and Related Technologies, 2009;2009(1):103-110.
    MyJurnal
    Indialite or α-cordierite was synthesized by glass crystallization method using mainly talc and kaolin and with small amount of MgO, Al2O3, SiO2 to compensate the chemical formulation of non-stoihiometric compositions of cordierite. (3MgO.1.5Al2O3.5SiO2). B2O3, P2O5 and CaO was also added to decrease the melting and sintering temperature of cordierite. The glasses were pelletized and sintered from 850 o C up to 1050 o C. Phase compositions of both heat treated glass was quantified by X-ray powder diffraction data by the Rietveld method using TOPAS Ver 3 software. Result shows that about 60wt% of α cordierite has successfully crystallized at 850 o C. Beside secondary phases (forsterite) which come from initial raw materials, phases from grinding media were also presents in the sample. The contamination was considered high since it has reacted with existence phases to form a new phase at higher temperature. Without any contamination from grinding it was expected to obtain more than 90wt% α cordierite using the same composition.
    Matched MeSH terms: Powder Diffraction
  19. Zeolite Linde Type L as micro-solid phase extraction sorbent for the high performance liquid chromatography determination of ochratoxin A in coffee and cereal
    Lee TP, Saad B, Ng EP, Salleh B
    J Chromatogr A, 2012 May 11;1237:46-54.
    PMID: 22444432 DOI: 10.1016/j.chroma.2012.03.031
    Zeolite Linde Type L (LTL) crystals with different length, diameter and particle size (nanosized LTL, rod LTL, cylinder LTL and needle LTL) were synthesized, characterized and were used as sorbent in the micro-solid phase extraction of ochratoxin A (OTA) before the high performance liquid chromatography detection. Under the optimized conditions, the detection limits of OTA for coffee and cereal were 0.09 ng g(-1) and 0.03 ng g(-1), respectively, while the quantification limits were 0.28 ng g(-1) and 0.08 ng g(-1), respectively. The recoveries of OTA of coffee and cereal spiked at 0.5, 10 and 25 ng g(-1) ranged from 91.7 to 101.0%. The proposed method was applied to forty-five samples of coffee and cereal. The presence of OTA was found in twenty-five samples, ranging from 0.28 to 9.33 ng g(-1).
    Matched MeSH terms: Powder Diffraction
  20. Enhanced Catalytic Activity, Facile Synthesis and Characterization Studies of Spinel Mn-Co Aluminate Nano-Catalysts
    Bhavani P, Manikandan A, Jaganathan SK, Shankar S, Antony SA
    J Nanosci Nanotechnol, 2018 Feb 01;18(2):1388-1395.
    PMID: 29448597 DOI: 10.1166/jnn.2018.14112
    Undoped and Mn2+ doped CoAl2O4 (MnxCo1-xAl2O4; x = 0.0 to 1.0) spinel nanoparticles were successfully synthesized by a microwave heating method using glycine as the fuel. X-ray powder diffraction (XRD) was confirmed the cubic spinel structure. The average crystallite size of the samples was found to be in the range of 16.46 nm to 20.25 nm calculated by Scherrer's formula. The nano-sized particle-like morphology of the samples was confirmed by high resolution scanning electron microscopy (HR-SEM) and transmission electron microscopy (HR-TEM) analysis. Energy dispersive X-ray (EDX) results showed the pure form of spinel aluminate structure. The band gap energy (Eg) of pure CoAl2O4 was estimated to be 3.68 eV from UV-Visible diffuse reflectance spectroscopy (DRS), and the Eg values increased with increase of Mn2+ ions, due to the smaller grain size. The magnetic hysteresis (M-H) loop showed the superparamagnetic nature, and the magnetization and coercivity values increased with increasing Mn2+ ions, which was confirmed by vibrating sample magnetometer (VSM). All compositions of the nano-catalysts were tested as catalyst successfully for the conversion of benzyl alcohol into benzaldehyde and observed good catalytic activity.
    Matched MeSH terms: Powder Diffraction
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