Field-flow fractionation is coming of age as a family of analytical methods for separating and characterizing macromolecules, nanoparticles, and particulates. The capabilities and versatility of these techniques are discussed in light of the challenges that are being addressed in analyzing nanometer-sized sample components and the insights gained through their use in applications ranging from materials science to biology. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html .).

Nano-sized metals have been introduced as a promising solution for microbial resistance to antimicrobial agents. Silver nanoparticles (AgNPs) have been proven to possess good antimicrobial activity. Green synthesis of AgNPs has been reported as safe, low cost and ecofriendly. This methodology uses extracts originating from different plants to reduce silver ions from AgNO 3 into nano-sized particles. In this study, extracts of several plants including ginger, garlic, capsicum and their mixtures were successfully used to produce AgNPs. Numerous spectroscopic, light scattering and microscopic techniques were employed to characterize the synthesized AgNPs. Agar well diffusion assay was performed to investigate the antimicrobial activity of AgNPs. The biosynthesized AgNPs have spherical shape with a size range of 20-70 nm. Garlic extract, pure or in mixture with ginger extract, generated AgNPs of the smallest size. The presence of the plant-origin capping agents surrounding AgNPs was proven by Fourier-transform infrared spectroscopy. The AgNPs, at a concentration of 50 µg/mL, demonstrated potent antimicrobial activity against Staphyloccocus aureus, Escherichia coli and Candida albicans as indicated by the zones of inhibitions. Our results revealed that AgNPs having potent antimicrobial activity could be prepared using different pure plant extracts and their mixtures.

Conventional formulations of antiviral drug acyclovir have various limitations such as low bioavailability. The current study was aimed at developing polymeric matrices for the controlled delivery of acyclovir using sericin as polymer and acrylic acid (AA) as a monomer. The free radical polymerization technique was used for hydrogel formulation. Briefly, sericin was chemically cross-linked with acrylic acid. N′-N′-methylene bis-acrylamide (MBA) and ammonium persulfate (APS) were used as cross-linker and initiator, respectively. FTIR spectra showed that acyclovir was successfully loaded into sericin hydrogel. SEM micrographs revealed that the outer surface was solid-like and smooth. According to DSC thermograms, the developed polymeric network was thermally stable. Amorphous nature of acyclovir was observed in XRD. The pH of medium and reactants’ concentration affected swelling dynamics and acyclovir release pattern. In addition, drug release occurred through a diffusion-controlled process. Sericin hydrogel suspension was well tolerable up to 3800 mg/kg of rabbits' body weight. Haematology and serum chemistry results were well within the range signifying normal liver and kidney functions. Similarly, histopathology slides of the rabbit’s vital organs were also in normal condition without causing any histopathological change. It was concluded from the findings that sericin-co-AA polymeric matrices are ideal for the pH-dependent delivery of acyclovir.

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A bstract Background: E-commerce of medicines has been extensively spread worldwide. Many reasons influence consumers to purchase their medical needs through the Internet, including low cost, availability, accessibility, and time saving. However, most of these medicines are substandard and counterfeit. Aim: To assess the perception of people in the UAE about purchasing medicines from online sources and to evaluate the quality of furosemide tablets from two different sources including illegal online source. Materials and Methods: A cross-sectional study was conducted on 528 participants in the UAE. The questionnaire included three parts to assess the public perception and experience toward purchasing medicines from online sources. Furosemide tablets, purchased from the UAE market and an illegal online source, were physically and chemically studied to assess their quality according to the British Pharmacopoeia (2018). Results: The survey results revealed that less than 10% of participants have purchased their medicines from online sources and mostly they were nonprescription products (78%). Most common motives for online purchasing were either unavailability in the local pharmacies (43%) or lower cost compared to that in local market (43%). The opinion of participants toward purchasing of online medicines was negative. On the other hand, the experimental analysis showed that online furosemide had failed to pass the chemical assay test (91.0% ± 0.8), which makes it a substandard product. Conclusion: This study showed that few consumers had considered purchasing pharmaceutical products from online sources as a feasible way to save money and time. However, most of them were in doubt about their quality, which encourages health-care providers to guide patients to government-supported websites if required. The study also showed that the quality of online medicines is questionable, indicating that these products are not equally effective as the medicines purchased from a local pharmacy.