Current Issue : October - December Volume : 2014 Issue Number : 4 Articles : 5 Articles
New antimicrobial properties of products derived from Humulus lupulus L. such as antiadherent and antibiofilm activities were\nevaluated. The growth of gram-positive but not gram-negative bacteria was inhibited to different extents by these compounds. An\nextract of hop cones containing 51% xanthohumol was slightly less active against S. aureus strains (MIC range 31.2ââ?¬â??125.0 ????g/mL)\nthan pure xanthohumol (MIC range 15.6ââ?¬â??62.5 ????g/mL).Thespent hop extract, free of xanthohumol, exhibited lower but still relevant\nactivity (MIC range 1-2mg/mL). There were positive coactions of hop cone, spent hop extracts, and xanthohumol with oxacillin\nagainst MSSA and with linezolid against MSSA and MRSA. Plant compounds in the culture medium at sub-MIC concentrations\ndecreased the adhesion of Staphylococci to abiotic surfaces, which in turn caused inhibition of biofilmformation.The rate ofmature\nbiofilm eradication by these products was significant.The spent hop extract atMIC reduced biofilm viability by 42.8%, the hop cone\nextract by 74.8%, and pure xanthohumol by 86.5%.When the hop cone extract or xanthohumol concentration was increased, almost\ncomplete biofilm eradication was achieved (97ââ?¬â??99%). This study reveals the potent antibiofilm activity of hop-derived compounds\nfor the first time....
The objective of present study was to develop Stevia rebaudiana as a sweetener in pharmaceutical formulation. The major constituents are stevioside and rebaudioside A. The leaves of stevia are the source of diterpene glycosides, viz. stevioside and rebaudioside. Stevioside is regenerated as a valuable natural sweetening agent because of its good taste and chemical stability. It has both economical and medicinal importance. Sugar is the most popular sweetener in the world. However due to adverse health effects of sucrose and known artificial sweeteners, interest increased in search for no calorie natural sweeteners has been intensified in recent years. Isolation of stevioside in purest form dried stevia leaves powder by different extraction method. Isolated stevioside was analysed and characterized by various spectral, chromatographic and physicochemical method. It was also compared with standard stevioside with all analytical methods. Stevioside also showed synergistic antidiabetic activity in type 2 diabetes with antidiabetic drug gliclazide. Its suspension was prepared by employing complex processing steps like wetting, suspending, thickening, flocculating agent and preservative where stevioside was used as sweetener for masking metallic taste of gliclazide. Optimized formulation batch of Suspension was evaluated with evolutionary parameters such as sedimentation rate, sedimentation volume, particle size, viscosity, zeta potential and also evaluated for in-vitro drug release study. The optimized batch showed drug release up to 98% in 1 hour. The formulation was stable during thermodynamic study. The formulation showed good stability. Confirmed by in-vitro drug release and viscosity determination. Stevioside showed good compatibility with all excipient of suspension....
Background: Cyclodextrins (CDs) have been shown to improve physicochemical and biopharmaceutical\nproperties of drugs when low solubility and low safety limit their use in the pharmaceutical field. Recently, a new\namphiphilic peptide-substituted-?-CD, hepta-(N-acetyl-Leu-Gly-Leu)-?-CD (hepta-(N-acetyl-LGL)-?-CD), is\ndeveloped which exhibited good solubility, strong inclusion ability and an appropriate average molecular weight.\nHowever, there is limited information available about its toxic effects. This study was designed to evaluate\ncytotoxic effects of the hepta-(N-acetyl-LGL)-?-CD (50, 200, 400, and 800 ?g/ml) on rat pheochromocytoma PC-12\ncells.\nResults: A significant reduction of cell viability with IC50 values of 1115.0 ?g/ml, 762.4 ?g/ml, and 464.9 ?g/ml at 6,\n12, and 24 h post-treatment, respectively, as well as increased lipid peroxide levels and DNA damage were observed.\nConclusions: In conclusion, hepta-(N-acetyl-Leu-Gly-Leu)-?-CD exhibit significant toxic properties at high concentrations,\nprobably through induction of oxidative stress and genotoxicity....
The work investigates the adhesive/cohesive molecular and physical interactions together with nanoscopic features of\ncommonly used orally disintegrating tablet (ODT) excipients microcrystalline cellulose (MCC) and D-mannitol. This helps to\nelucidate the underlying physico-chemical and mechanical mechanisms responsible for powder densification and optimum\nproduct functionality. Atomic force microscopy (AFM) contact mode analysis was performed to measure nano-adhesion\nforces and surface energies between excipient-drug particles (6-10 different particles per each pair). Moreover, surface\ntopography images (100 nm2ââ?¬â??10 mm2) and roughness data were acquired from AFM tapping mode. AFM data were related\nto ODT macro/microscopic properties obtained from SEM, FTIR, XRD, thermal analysis using DSC and TGA, disintegration\ntesting, Heckel and tabletability profiles. The study results showed a good association between the adhesive molecular and\nphysical forces of paired particles and the resultant densification mechanisms responsible for mechanical strength of\ntablets. MCC micro roughness was 3 times that of D-mannitol which explains the high hardness of MCC ODTs due to\nmechanical interlocking. Hydrogen bonding between MCC particles could not be established from both AFM and FTIR solid\nstate investigation. On the contrary, D-mannitol produced fragile ODTs due to fragmentation of surface crystallites during\ncompression attained from its weak crystal structure. Furthermore, AFM analysis has shown the presence of extensive micro\nfibril structures inhabiting nano pores which further supports the use of MCC as a disintegrant. Overall, excipients (and\nmodel drugs) showed mechanistic behaviour on the nano/micro scale that could be related to the functionality of materials\non the macro scale....
Xanthan gum is a high-molecular-weight polysaccharide secreted by the microorganism Xanthomonas campestris and produced commercially in a batch fermentation process. It hydrates in cold water to give a viscous solution with pseudoplastic flow behaviour. Because of its physical properties, it is widely used as a thickener or viscoser in both food and non-food industries. Xanthan gum is also used as a stabilizer for a wide variety of suspensions, emulsions and foams. This gives excellent suspension and cling at low shear and excellent mouth feel and pouring properties at high shear. The xanthan gum molecule has a cellulosic backbone with side chains that wrap around the backbone protecting it and conferring excellent stability across a wide pH range and tolerance of high salt concentrations and ingredients such as glycerol and alcohol. The rigid backbone helps to maintain viscosity during heating. Xanthan gum shows synergistic thickening with guar gum and forms very elastic cohesive gels with locust bean gum and konjac mannan. Non-food uses include oil field, personal care, pharmaceutical and home care products. Typical food applications include sauces and dressings, baked goods, beverages, desserts and ice creams. This article outlines overview of the applications and industrial production of xanthan....
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