Elucidating the Antibacterial Potential of PEG Modified Silver Nanoparticles

The present study provides an insight of antibacterial potential of PEG modified AgNPs. AgNPs were found to be ~26 nm by XRD analysis apart from exhibiting its ultravoilet spectra peak at 250 nm. The Fourier transform-infrared spectroscopy further confirmed the observance of peaks between 650 to 500 cm‑1 in the synthesized AgNPs. Antimicrobial characterization was monitored by colony forming units (CFU) on agar plates. AgNPs showed 20x109/ml CFU after 24 hrs of incubation at 20 mM AgNPs concentration as against 29x109/ml CFU under similar incubation conditions in the modified AgNPs. Moreover, zone of inhibition (ZOI) appeared as 3.1 and 3.8 cm at 0.2 and 0.4 mM at AgNPs, respectively in E.coli in contrast to 3.5 and 4.5 cm, respectively for modified AgNPs under similar conditions. ZOI for S. aureus showed 3.2 and 3.8 cm, respectively at 0.2 and 0.4 mM concentration for AgNPs while modified AgNPs exhibited ZOI at 3.8 and 4.4 cm, respectively under similar incubation conditions. Their toxic effect was demonstrated by MTT assay to point out their relevance as antimicrobial agent

Photodegradation of levofloxacin in aqueous and organic solvents: A kinetic study

The kinetics of photodegradation of levofloxacin in solution on UV irradiation in the pH range 2.0–12.0 has been studied using a HPLC method. Levofloxacin undergoes first-order kinetics in the initial stages of the reaction and the apparent first-order rate constants are of the order of 0.167 to 1.807×10–3 min–1. The rate-pH profile is represented by a curve indicating the presence of cationic, dipolar and anionic species during the reaction. The singly ionized form of the molecule is non-fluorescent and is less susceptible to photodegradation. The increase in the degradation rate in the pH range 5.0–9.0 may be due to greater reactivity of the ionized species existing in that range. The rate appears to vary with a change in the degree of ionization of the species present in a particular pH range and their susceptibility to photodegradation. Above pH 9, the decrease in the rate of photodegradation may be result of deprotonation of the piperazinyl group. The levofloxacin molecule is more stable in the pH range around 7, which is then suitable for formulation purposes. The photodegradation of levofloxacin was found to be affected by the dielectric constant and viscosity of the medium

FORMULATION AND CHARACTERIZATION OF FLUCONAZOLE LOADED OLIVE OIL NANOEMULSIONS

Present study was carried out to develop and evaluate olive oil based nano-emulsion for transdermal delivery of fluconazole, a bistriazole based antifungal agent with poor water solubility and lipophilicity. Olive oil, a natural non-irritating, non-toxic proposed permeation enhancer, is known to have some antifungal activity as well. Screening of common emulsifiers like Tweens (Tween 20, tween 60, tween 80), Spans (span 60, span 80), brij 35, puronic 127, and poloxamer 188 were done based on solubility of fluconazole in these surfactants followed by their efficiency to emulsify olive oil in water. Co-emulsifiers such as glycols (polyethylene glycol 200, polyethylene glycol 400, propylene glycol), and short chain alcohols (ethanol, propanol, butanol and octanol) were also screened similarly. Tween 80 and butanol were selected as emulsifier and co-emulsifier respectively to formulate nano-emulsion by aqueous titration method. However, separation was observed after 24 hours. Therefore, span 80 was added as an auxiliary emulsifier to improve emulsification efficiency. Finally, a blend of tween 80, span 80 and butanol was optimized as emulsifier (56 % wt/wt) to emulsify 9 % wt/wt of olive oil in 33 % wt/wt water. Pseudo-ternary phase diagram was employed to identify and optimize the components. Optimized formulation based on phase separation and thermokinetic stability was characterized for globule size, size distribution, zeta potential, viscosity, refractive index and pH. Globule size analysis by zetasizer nano ZS was further confirmed by transmission electron microscopy. Permeation flux of fluconazole from optimized formulation through artificial skin was approximately three fold higher than the control. In conclusion, developed olive oil based nano-emulsion of fluconazole demonstrated promising solubility, permeability and stability. Keywords: Fluconazole, olive oil, nano-emulsion, transdermal permeatio

Green synthesis and biological evaluation of novel 5-fluorouracil derivatives as potent anticancer agents

This study reports the formation of 5-FU co-crystals with four different pharmacologically safe co-formers; Urea, Thiourea, Acetanilide and Aspirin using methanol as a solvent. Two fabrication schemes were followed i.e., solid-state grinding protocol, in which API and co-formers were mixed through vigorous grinding while in the other method separate solutions of both the components were made and mixed together. The adopted approaches offer easy fabrication protocols, no temperature maintenance requirements, no need of expensive solvents, hardly available apparatus, isolation and purification of the desired products. In addition, there is no byproducts formation, In fact, a phenomenon embracing the requirements of green synthesis. Through FTIR analysis; for API the Nsingle bondH absorption frequency was recorded at 3409.02 cm−1 and that of single bondCdouble bondO was observed at 1647.77 cm−1. These characteristics peaks of 5-FU were significantly shifted and recorded at 3499.40 cm−1 and 1649.62 cm−1 for 5-FU-Ac (3B) and 3496.39 cm−1 and 1659.30 cm−1 for 5-FU-As (4B) co-crystals for Nsingle bondH and single bondCdouble bondO groups respectively. The structural differences between API and co-crystals were further confirmed through PXRD analysis. The characteristic peak of 5-FU at 2θ = 28.79918o was significantly shifted in the graphs of co-crystals not only in position but also with respect to intensity and FWHM values. In addition, new peaks were also recorded in all the spectra of co-formers confirming the structural differences between API and co-formers. In addition, percent growth inhibition was also observed by all the co-crystals through MTT assay against HCT 116 colorectal cell lines in vitro. At four different concentrations; 25, 50, 100 and 200 µg/mL, slightly different trends of the effectiveness of API and co-crystals were observed. However; among all the co-crystal forms, 5-FU-thiourea co-crystals obtained through solution method (2B) proved to be the most effective growth inhibitor at all the four above mentioned concentrations

Protective Effect of Solanum nigrum

The prophylactic or curative antioxidant efficacy of crude extract and the active constituent of S. nigrum leaves were evaluated in modulating inherent antioxidant system altered due to immobilization stress in rat brain tissues, in terms of measurement of glutathione (GSH), lipid peroxidation (thiobarbituric acid reactive substances, TBARS), and free radical scavenging enzymes activities. Rats were treated with single dose of crude extract of S. nigrum prior to and after 6 h of immobilization stress exposure. Exposure to immobilization stress resulted in a decrease in the brain levels of glutathione, SOD, GST, and catalase, with an increase in thiobarbituric acid reactive substances (TBARS) levels. Treatment of S. nigrum extract and its active constituents to both pre- and poststressed rats resulted in significant modulation in the above mentioned parameters towards their control values with a relative dominance by the latter. Brain is vulnerable to stress induced prooxidant insult due to high levels of fat content. Thus, as a safe herbal medication the S. nigrum leaves extract or its isolated constituents can be used as nutritional supplement for scavenging free radicals generated in the brain due to physical or psychological stress or any neuronal diseases per se

Biotechnological application of Aspergillus oryzae β-galactosidase immobilized on glutaraldehyde modified zinc oxide nanoparticles

The current research demonstrates the synthesis of zinc oxide nanoparticles (ZnO-NPs) via green nanotechnology approach (Azatirachta indica leaves). The size of the synthesized ZnO-NPs was confirmed as 27 nm by TEM. Glutaraldehyde was used to modify the surface of the developed ZnO-NPs in order to promote covalent binding of Aspergillus oryzae β-galactosidase. Enzyme activity was achieved as 93% on glutaraldehyde modified ZnO-NPs. The immobilized enzyme exhibited significant enhancement in activity under extreme temperature and pH variations, as compared to the soluble β-galactosidase (SβG). It was further observed that the immobilized enzyme retained 58% activity at 5% galactose concentration. However, under similar experimental conditions, SβG showed 27% activity. Reusability of immobilized enzyme revealed that it retained 89% activity even after fifth repeated use, and hence could be recovered easily by centrifugation for repeated use in biotechnological applications. Batch reactor experiment indicates that the immobilized enzyme displayed 81% and 70% lactose hydrolysis at 50 °C and 60 °C, respectively as compared to 70% and 58% lactose hydrolysis by soluble enzyme under identical conditions after 9 h