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Mojtaba Beheshti - One of the best experts on this subject based on the ideXlab platform.
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oral fluoroquinolone therapy results in Drug Adsorption on ureteral stents and prevention of biofilm formation
International Journal of Antimicrobial Agents, 2001Co-Authors: Gregor Reid, Marc Habash, Darrell Vachon, John D. Denstedt, John V. Riddell, Mojtaba BeheshtiAbstract:The oral administration of ciprofloxacin (250mg bid) and ofloxacin (300mg bid) in 40 patients with ureteral stents, led to Drug levels on all the device surfaces that were higher than the minimum inhibitory concentration (MIC) of Escherichia coli (0.004--0.015 mg/l), the most common uropathogen. The Drug levels in the film were higher than the MIC of other common pathogens, namely Pseudomonas aeruginosa (0.25--1.0 mg/l), Enterococcus faecalis (0.25--2.0 mg/l) and Staphylococcus aureus (0.12--0.5 mg/l) in a few cases (six, three and 14 cases out of 40, respectively). For both antibiotics, the concentrations were greater than the MIC of many uropathogens on the film surrounding the devices (0.89 vs 0.31 mg/l respectively, P=0.05), and on the devices themselves (0.22 vs. 0.12 mg/l, P=0.207). Adsorption of the antibiotics was higher to the film than to the stent (P<0.0001). Ciprofloxacin concentration on the film surrounding the stents was significantly higher than that of ofloxacin (P=0.05), while there was no statistical concentration difference between the two antibiotics adsorbed onto the actual devices (P=0.207). No bacteria were found in patients' urine and no biofilms were detected. This is the first report of an oral antibiotic being adsorbed onto medical devices. It potentially provides a new approach of preventing infection, and avoids the need to pre-coat devices with agents whose use will be restricted once bacteria develop resistance to them. If biomaterial properties can be enhanced to increase further the adsorptive concentration of Drug, the risk of infections and recalcitrant biofilm formation could be significantly reduced in a highly susceptible patient population.
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Oral fluoroquinolone therapy results in Drug Adsorption on ureteral stents and prevention of biofilm formation.
International journal of antimicrobial agents, 2001Co-Authors: Gregor Reid, Marc Habash, Darrell Vachon, John D. Denstedt, John V. Riddell, Mojtaba BeheshtiAbstract:The oral administration of ciprofloxacin (250mg bid) and ofloxacin (300mg bid) in 40 patients with ureteral stents, led to Drug levels on all the device surfaces that were higher than the minimum inhibitory concentration (MIC) of Escherichia coli (0.004--0.015 mg/l), the most common uropathogen. The Drug levels in the film were higher than the MIC of other common pathogens, namely Pseudomonas aeruginosa (0.25--1.0 mg/l), Enterococcus faecalis (0.25--2.0 mg/l) and Staphylococcus aureus (0.12--0.5 mg/l) in a few cases (six, three and 14 cases out of 40, respectively). For both antibiotics, the concentrations were greater than the MIC of many uropathogens on the film surrounding the devices (0.89 vs 0.31 mg/l respectively, P=0.05), and on the devices themselves (0.22 vs. 0.12 mg/l, P=0.207). Adsorption of the antibiotics was higher to the film than to the stent (P
Gregor Reid - One of the best experts on this subject based on the ideXlab platform.
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oral fluoroquinolone therapy results in Drug Adsorption on ureteral stents and prevention of biofilm formation
International Journal of Antimicrobial Agents, 2001Co-Authors: Gregor Reid, Marc Habash, Darrell Vachon, John D. Denstedt, John V. Riddell, Mojtaba BeheshtiAbstract:The oral administration of ciprofloxacin (250mg bid) and ofloxacin (300mg bid) in 40 patients with ureteral stents, led to Drug levels on all the device surfaces that were higher than the minimum inhibitory concentration (MIC) of Escherichia coli (0.004--0.015 mg/l), the most common uropathogen. The Drug levels in the film were higher than the MIC of other common pathogens, namely Pseudomonas aeruginosa (0.25--1.0 mg/l), Enterococcus faecalis (0.25--2.0 mg/l) and Staphylococcus aureus (0.12--0.5 mg/l) in a few cases (six, three and 14 cases out of 40, respectively). For both antibiotics, the concentrations were greater than the MIC of many uropathogens on the film surrounding the devices (0.89 vs 0.31 mg/l respectively, P=0.05), and on the devices themselves (0.22 vs. 0.12 mg/l, P=0.207). Adsorption of the antibiotics was higher to the film than to the stent (P<0.0001). Ciprofloxacin concentration on the film surrounding the stents was significantly higher than that of ofloxacin (P=0.05), while there was no statistical concentration difference between the two antibiotics adsorbed onto the actual devices (P=0.207). No bacteria were found in patients' urine and no biofilms were detected. This is the first report of an oral antibiotic being adsorbed onto medical devices. It potentially provides a new approach of preventing infection, and avoids the need to pre-coat devices with agents whose use will be restricted once bacteria develop resistance to them. If biomaterial properties can be enhanced to increase further the adsorptive concentration of Drug, the risk of infections and recalcitrant biofilm formation could be significantly reduced in a highly susceptible patient population.
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Oral fluoroquinolone therapy results in Drug Adsorption on ureteral stents and prevention of biofilm formation.
International journal of antimicrobial agents, 2001Co-Authors: Gregor Reid, Marc Habash, Darrell Vachon, John D. Denstedt, John V. Riddell, Mojtaba BeheshtiAbstract:The oral administration of ciprofloxacin (250mg bid) and ofloxacin (300mg bid) in 40 patients with ureteral stents, led to Drug levels on all the device surfaces that were higher than the minimum inhibitory concentration (MIC) of Escherichia coli (0.004--0.015 mg/l), the most common uropathogen. The Drug levels in the film were higher than the MIC of other common pathogens, namely Pseudomonas aeruginosa (0.25--1.0 mg/l), Enterococcus faecalis (0.25--2.0 mg/l) and Staphylococcus aureus (0.12--0.5 mg/l) in a few cases (six, three and 14 cases out of 40, respectively). For both antibiotics, the concentrations were greater than the MIC of many uropathogens on the film surrounding the devices (0.89 vs 0.31 mg/l respectively, P=0.05), and on the devices themselves (0.22 vs. 0.12 mg/l, P=0.207). Adsorption of the antibiotics was higher to the film than to the stent (P
Lasse Murtomäki - One of the best experts on this subject based on the ideXlab platform.
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Drug Adsorption on bovine and porcine sclera studied with streaming potential
Journal of pharmaceutical sciences, 2013Co-Authors: Lasse Murtomäki, Tuomas Vainikka, Silvia Pescina, Sara NicoliAbstract:The affinity of a Drug to a biological membrane can affect the distribution and the availability of the active compound to its target. Adsorption is usually determined with in vitro distribution studies based on partitioning of the Drug between buffer and tissue, which have limitations such as the high variability of the uptake data and the need for high accuracy in the measurement of Drug concentration. Furthermore, distribution studies yield solute concentrations in the bulk of the tissue, whereas electrokinetic phenomena such as streaming potential and electroosmosis reflect the electric charge density on a membrane surface. Streaming potential thus can be used in studying the conditions, by which the charge sign and density can be regulated. That, in turn, has significance to electroosmotic transport mechanism during iontophoresis. In this communication, the Adsorption of model compounds methylprednisolone sodium succinate, propranolol, and cytochrome C on bovine and porcine sclera is determined as a function of their concentration by measuring streaming potential. Both membranes had negative streaming potential, proving that they carry negative charge, but had different values at negative and positive pressure differences, which is addressed to the structural asymmetry of these membranes. Bovine sclera had a clearly higher value of streaming potential, ca. -26 nV/Pa, than porcine sclera, ca. -7 nV/Pa (10 mM NaCl solution). All the model compounds were adsorbed on bovine and porcine sclera already in the millimolar concentration range and can have an impact to electroosmosis during transscleral iontophoresis. The results obtained help to better elucidate the phenomena involved in transscleral transport, both in passive diffusion and in iontophoresis, supporting the future application of iontophoresis to the noninvasive delivery of Drugs to the posterior segment of the human eye.
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Drug Adsorption in Human Skin: A Streaming Potential Study
Journal of pharmaceutical sciences, 2003Co-Authors: Johanna Raiman, Kaisa Hänninen, Kyösti Kontturi, Lasse Murtomäki, Jouni HirvonenAbstract:The objective of this study was to investigate the Drug Adsorption process in human skin using in vitro streaming potential measurements. Streaming potential is an electrokinetic phenomenon, which reflects both the charge density and the pore size of a membrane. Thus, the Adsorption of charged solutes on the pore walls can be detected as a change of streaming potential, viz., as a change in the slope deltaE/deltaP. In these streaming potential measurements, hydrophilic nadolol and luteinizing hormone-releasing hormone, and lipophilic propranolol and Nafarelin were used as model Drugs. As could be expected, the hydrophilic Drugs did not change the slope. The more lipophilic propranolol and Nafarelin, instead, changed the slope. Propranolol changed the slope gradually from negative to positive when the concentration was increased from 1 to 10 mM. With Nafarelin, a straight line with a slope of about 0 was obtained at pH 7.3 and an ascending curve at pH 4.2. These results indicate that the negative charges on the pore walls of human skin are blocked by Adsorption of the lipophilic cations. The Adsorption of lipophilic cations in the skin alters the permselectivity of the skin, which, in turn, may lead to the inhibition of electroosmotic flow across the skin during iontophoresis and to the shut down of transdermal Drug permeation of higher molecular weight Drugs.
Sara Nicoli - One of the best experts on this subject based on the ideXlab platform.
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Drug Adsorption on bovine and porcine sclera studied with streaming potential
Journal of pharmaceutical sciences, 2013Co-Authors: Lasse Murtomäki, Tuomas Vainikka, Silvia Pescina, Sara NicoliAbstract:The affinity of a Drug to a biological membrane can affect the distribution and the availability of the active compound to its target. Adsorption is usually determined with in vitro distribution studies based on partitioning of the Drug between buffer and tissue, which have limitations such as the high variability of the uptake data and the need for high accuracy in the measurement of Drug concentration. Furthermore, distribution studies yield solute concentrations in the bulk of the tissue, whereas electrokinetic phenomena such as streaming potential and electroosmosis reflect the electric charge density on a membrane surface. Streaming potential thus can be used in studying the conditions, by which the charge sign and density can be regulated. That, in turn, has significance to electroosmotic transport mechanism during iontophoresis. In this communication, the Adsorption of model compounds methylprednisolone sodium succinate, propranolol, and cytochrome C on bovine and porcine sclera is determined as a function of their concentration by measuring streaming potential. Both membranes had negative streaming potential, proving that they carry negative charge, but had different values at negative and positive pressure differences, which is addressed to the structural asymmetry of these membranes. Bovine sclera had a clearly higher value of streaming potential, ca. -26 nV/Pa, than porcine sclera, ca. -7 nV/Pa (10 mM NaCl solution). All the model compounds were adsorbed on bovine and porcine sclera already in the millimolar concentration range and can have an impact to electroosmosis during transscleral iontophoresis. The results obtained help to better elucidate the phenomena involved in transscleral transport, both in passive diffusion and in iontophoresis, supporting the future application of iontophoresis to the noninvasive delivery of Drugs to the posterior segment of the human eye.
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RESEARCH ARTICLE Drug Adsorption on Bovine and Porcine Sclera Studied with Streaming Potential
2013Co-Authors: Lasse Murtom, Tuomas Vainikka, Silvia Pescina, Sara NicoliAbstract:The affinity of a Drug to a biological membrane can affect the distribution and the availability of the active compound to its target. Adsorption is usually determined with in vitro distribution studies based on partitioning of the Drug between buffer and tissue, which have limitations such as the high variability of the uptake data and the need for high accu- racy in the measurement of Drug concentration. Furthermore, distribution studies yield solute concentrations in the bulk of the tissue, whereas electrokinetic phenomena such as streaming potential and electroosmosis reflect the electric charge density on a membrane surface. Stream- ing potential thus can be used in studying the conditions, by which the charge sign and density can be regulated. That, in turn, has significance to electroosmotic transport mechanism during iontophoresis. In this communication, the Adsorption of model compounds methylprednisolone sodium succinate, propranolol, and cytochrome C on bovine and porcine sclera is determined as a function of their concentration by measuring streaming potential. Both membranes had negative streaming potential, proving that they carry negative charge, but had different values at negative and positive pressure differences, which is addressed to the structural asymmetry of these membranes. Bovine sclera had a clearly higher value of streaming potential, ca. −26 nV/ Pa, than porcine sclera, ca. −7 nV/Pa (10 mM NaCl solution). All the model compounds were adsorbed on bovine and porcine sclera already in the millimolar concentration range and can have an impact to electroosmosis during transscleral iontophoresis. The results obtained help to better elucidate the phenomena involved in transscleral transport, both in passive diffusion and in iontophoresis, supporting the future application of iontophoresis to the noninvasive de- livery of Drugs to the posterior segment of the human eye. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci
John D. Denstedt - One of the best experts on this subject based on the ideXlab platform.
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oral fluoroquinolone therapy results in Drug Adsorption on ureteral stents and prevention of biofilm formation
International Journal of Antimicrobial Agents, 2001Co-Authors: Gregor Reid, Marc Habash, Darrell Vachon, John D. Denstedt, John V. Riddell, Mojtaba BeheshtiAbstract:The oral administration of ciprofloxacin (250mg bid) and ofloxacin (300mg bid) in 40 patients with ureteral stents, led to Drug levels on all the device surfaces that were higher than the minimum inhibitory concentration (MIC) of Escherichia coli (0.004--0.015 mg/l), the most common uropathogen. The Drug levels in the film were higher than the MIC of other common pathogens, namely Pseudomonas aeruginosa (0.25--1.0 mg/l), Enterococcus faecalis (0.25--2.0 mg/l) and Staphylococcus aureus (0.12--0.5 mg/l) in a few cases (six, three and 14 cases out of 40, respectively). For both antibiotics, the concentrations were greater than the MIC of many uropathogens on the film surrounding the devices (0.89 vs 0.31 mg/l respectively, P=0.05), and on the devices themselves (0.22 vs. 0.12 mg/l, P=0.207). Adsorption of the antibiotics was higher to the film than to the stent (P<0.0001). Ciprofloxacin concentration on the film surrounding the stents was significantly higher than that of ofloxacin (P=0.05), while there was no statistical concentration difference between the two antibiotics adsorbed onto the actual devices (P=0.207). No bacteria were found in patients' urine and no biofilms were detected. This is the first report of an oral antibiotic being adsorbed onto medical devices. It potentially provides a new approach of preventing infection, and avoids the need to pre-coat devices with agents whose use will be restricted once bacteria develop resistance to them. If biomaterial properties can be enhanced to increase further the adsorptive concentration of Drug, the risk of infections and recalcitrant biofilm formation could be significantly reduced in a highly susceptible patient population.
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Oral fluoroquinolone therapy results in Drug Adsorption on ureteral stents and prevention of biofilm formation.
International journal of antimicrobial agents, 2001Co-Authors: Gregor Reid, Marc Habash, Darrell Vachon, John D. Denstedt, John V. Riddell, Mojtaba BeheshtiAbstract:The oral administration of ciprofloxacin (250mg bid) and ofloxacin (300mg bid) in 40 patients with ureteral stents, led to Drug levels on all the device surfaces that were higher than the minimum inhibitory concentration (MIC) of Escherichia coli (0.004--0.015 mg/l), the most common uropathogen. The Drug levels in the film were higher than the MIC of other common pathogens, namely Pseudomonas aeruginosa (0.25--1.0 mg/l), Enterococcus faecalis (0.25--2.0 mg/l) and Staphylococcus aureus (0.12--0.5 mg/l) in a few cases (six, three and 14 cases out of 40, respectively). For both antibiotics, the concentrations were greater than the MIC of many uropathogens on the film surrounding the devices (0.89 vs 0.31 mg/l respectively, P=0.05), and on the devices themselves (0.22 vs. 0.12 mg/l, P=0.207). Adsorption of the antibiotics was higher to the film than to the stent (P
