The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Sean P. Gorman - One of the best experts on this subject based on the ideXlab platform.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical Research, 2002Co-Authors: David S. Jones, James G. Mcgovern, A. David Woolfson, Colin G. Adair, Sean P. GormanAbstract:Purpose . Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence ( Staphylococcus aureus and Pseudomonas aeruginosa ). Methods . PVC emulsion was cured in the presence of Hexetidine (0-20% w/w) and was characterized in terms of drug release, surface properties (i.e., microrugosity/contact angle), mechanical (tensile) properties, and resistance to microbial adherence. Results . Under sink conditions, Hexetidine release from PVC was diffusion-controlled. Increasing the concentration of Hexetidine from 1% to 10% (w/w) (but not from 10% to 20% w/w) increased the subsequent rate of drug release. In general, increasing the concentration of Hexetidine decreased both the tensile properties and hydrophobicity, yet increased PVC microrugosity. Following Hexetidine release (21 days), the surface properties were similar to those of native PVC. The resistance of Hexetidine-containing PVC (1% or 5%) to microbial adherence (following defined periods of drug release) was greater than that of native PVC and was constant over the examined period of Hexetidine release. Conclusions . ET PVC containing 1% (w/w) Hexetidine offered an appropriate balance between suitable physicochemical properties and resistance to microbial adherence. This may offer an approach with which to reduce the incidence of ventilator-associated pneumonia.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical research, 2002Co-Authors: David S. Jones, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, Sean P. GormanAbstract:Purpose. Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence (Staphylococcus aureus and Pseudomonas aeruginosa).
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The concomitant development of poly(vinyl chloride)-related biofilm and antimicrobial resistance in relation to ventilator-associated pneumonia.
Biomaterials, 2001Co-Authors: Sean P. Gorman, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, David S. JonesAbstract:Abstract Ventilator-associated pneumonia is a major cause of death in intensive care patients and the endotracheal tube, commonly fabricated from poly(vinyl chloride) (PVC), is acknowledged as a significant factor in this. Bacteria colonise the biomaterial, thereby adopting a sessile mode of growth that progresses to the establishment of an antibiotic-resistant biofilm by the accretion of a protective glycocalyx. This study examined the sequential steps involved in the formation of biofilm on PVC by atomic force microscopy and the concomitant development of resistance to an antibiotic (ceftazidime) and to a non-antibiotic antimicrobial agent (Hexetidine). Staphylococcus aureus and Pseudomonas aeruginosa isolated from ET tube biofilm were employed. The surface microrugosity of bacteria growing in sessile mode on PVC decreased significantly ( p S. aureus were lower than for Ps. aeruginosa . Furthermore, sessile populations of S. aureus and Ps. aeruginosa on PVC exhibited greater resistance to both ceftazidime and Hexetidine when compared to planktonic bacterial growth. The efficacy of the agents, determined by kill kinetics, against sessile bacteria was dependent on age, with established biofilms (⩾24 h) significantly more resistant ( p p
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Determination of the salivary retention of Hexetidine in-vivo by high-performance liquid chromatography.
The Journal of pharmacy and pharmacology, 2000Co-Authors: Colin P. Mccoy, David S. Jones, Sean P. Gorman, J.g. Mcgovern, A. David WoolfsonAbstract:The non-antibiotic antimicrobial agent Hexetidine is widely used at a concentration of 0.1% w/v as an oral rinse to reduce the number of viable microorganisms within the oral cavity. However, following use, the available concentration of Hexetidine in the oral cavity declines with time, thus compromising the resultant antimicrobial activity. It is, therefore, desirable to determine the persistence of the agent in the oral cavity by quantification of the drug concentration in saliva, thus enabling prediction of its antimicrobial activity in the oral environment. A rapid reverse-phase HPLC method was therefore developed and validated for Hexetidine in aqueous solution (Oraldene) and in saliva samples collected from volunteers post-rinsing with 15 mL of Hexetidine oral rinse for 30s. The HPLC assay was sufficiently sensitive to accurately detect Hexetidine in saliva up to 25 min after in-vivo use of a commercial oral rinse. Furthermore, it was possible to detect Hexetidine below the published minimum inhibitory concentrations (MICs) for a selection of microorganisms. From these data a first-order elimination rate constant of Hexetidine from the oral cavity was determined post-rinsing in each of six volunteers. The validated HPLC assay method presented is useful for the assay of Hexetidine in the oral cavity both at and below MICs. The first-order elimination rate constant shows significant variation between volunteers.
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The Effects of Hexetidine (Oraldene™) on the Adherence of Candida Albicans to Human Buccal Epithelial Cells In Vitro and Ex Vivo and on In Vitro Morphogenesis
Pharmaceutical Research, 1997Co-Authors: David S. Jones, James G. Mcgovern, A. David Woolfson, Sean P. GormanAbstract:Purpose . This study reports the effects of Hexetidine (Oraldene^™) on two virulence attributes of Candida albicans , namely, in vitro and ex vivo adherence of yeast cells to buccal epithelial cells (EEC) and in vitro morphogenesis. Methods . The effects of Hexetidine treatment of either yeast cells (stationary and exponential phases) or BEC on Candidal adherence, in terms of viable and non-viable adherent yeast cells, were evaluated using an acridine orange stain in conjunction with fluorescence microscopy. Ex vivo anti-adherence effects were determined by rinsing BEC in vivo with Hexetidine (0.1%), removal of BEC after defined periods and inclusion in the adherence assay. The effects of Hexetidine on morphogenesis were evaluated using light microscopy. Yeast cell viability following exposure to a range of concentration of Hexetidine (0.005-0.1 % v/v) for defined periods was determined following serial dilution and enumeration on solid media. Results . Treatment of stationary and exponential phase yeast cells or BEC with Hexetidine (0.1%) for a range of times (10−300 s) or, alternatively, with a range of concentrations of Hexetidine (0.005−0.1 %) for a fixed time (30s) significantly decreased the resultant Candidal / epithelial adhesion. No correlations were observed between reduced adherence and either time of treatment or Hexetidine concentration. In vivo treatment of BEC with Hexetidine (0.1%) for 30s resulted in prolonged and significant reductions in the ex vivo adherence of both viable and non-viable yeast cells for periods of up to (and including) four hours post-rinsing. Treatment of C. albicans blastospores with Hexetidine (0.05, 0.1% v/v) for 10s and 30s totally inhibited Candida morphogenesis, whereas treatment with lower antiseptic concentrations significantly reduced the extent of Candida morphogenesis and the rate of hyphal development. The effects of Hexetidine on yeast cell viability were both concentration and time-dependent. Conclusions . The reduced adherence of C. albicans to BEC and the modification or inhibition of morphogenesis following exposure to Hexetidine suggests a clinical role for Hexetidine in the prophylaxis of both superficial candidosis and the systemic complications resulting from invasion of sub-epithelial tissue.
David S. Jones - One of the best experts on this subject based on the ideXlab platform.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical Research, 2002Co-Authors: David S. Jones, James G. Mcgovern, A. David Woolfson, Colin G. Adair, Sean P. GormanAbstract:Purpose . Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence ( Staphylococcus aureus and Pseudomonas aeruginosa ). Methods . PVC emulsion was cured in the presence of Hexetidine (0-20% w/w) and was characterized in terms of drug release, surface properties (i.e., microrugosity/contact angle), mechanical (tensile) properties, and resistance to microbial adherence. Results . Under sink conditions, Hexetidine release from PVC was diffusion-controlled. Increasing the concentration of Hexetidine from 1% to 10% (w/w) (but not from 10% to 20% w/w) increased the subsequent rate of drug release. In general, increasing the concentration of Hexetidine decreased both the tensile properties and hydrophobicity, yet increased PVC microrugosity. Following Hexetidine release (21 days), the surface properties were similar to those of native PVC. The resistance of Hexetidine-containing PVC (1% or 5%) to microbial adherence (following defined periods of drug release) was greater than that of native PVC and was constant over the examined period of Hexetidine release. Conclusions . ET PVC containing 1% (w/w) Hexetidine offered an appropriate balance between suitable physicochemical properties and resistance to microbial adherence. This may offer an approach with which to reduce the incidence of ventilator-associated pneumonia.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical research, 2002Co-Authors: David S. Jones, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, Sean P. GormanAbstract:Purpose. Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence (Staphylococcus aureus and Pseudomonas aeruginosa).
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The concomitant development of poly(vinyl chloride)-related biofilm and antimicrobial resistance in relation to ventilator-associated pneumonia.
Biomaterials, 2001Co-Authors: Sean P. Gorman, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, David S. JonesAbstract:Abstract Ventilator-associated pneumonia is a major cause of death in intensive care patients and the endotracheal tube, commonly fabricated from poly(vinyl chloride) (PVC), is acknowledged as a significant factor in this. Bacteria colonise the biomaterial, thereby adopting a sessile mode of growth that progresses to the establishment of an antibiotic-resistant biofilm by the accretion of a protective glycocalyx. This study examined the sequential steps involved in the formation of biofilm on PVC by atomic force microscopy and the concomitant development of resistance to an antibiotic (ceftazidime) and to a non-antibiotic antimicrobial agent (Hexetidine). Staphylococcus aureus and Pseudomonas aeruginosa isolated from ET tube biofilm were employed. The surface microrugosity of bacteria growing in sessile mode on PVC decreased significantly ( p S. aureus were lower than for Ps. aeruginosa . Furthermore, sessile populations of S. aureus and Ps. aeruginosa on PVC exhibited greater resistance to both ceftazidime and Hexetidine when compared to planktonic bacterial growth. The efficacy of the agents, determined by kill kinetics, against sessile bacteria was dependent on age, with established biofilms (⩾24 h) significantly more resistant ( p p
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Determination of the salivary retention of Hexetidine in-vivo by high-performance liquid chromatography.
The Journal of pharmacy and pharmacology, 2000Co-Authors: Colin P. Mccoy, David S. Jones, Sean P. Gorman, J.g. Mcgovern, A. David WoolfsonAbstract:The non-antibiotic antimicrobial agent Hexetidine is widely used at a concentration of 0.1% w/v as an oral rinse to reduce the number of viable microorganisms within the oral cavity. However, following use, the available concentration of Hexetidine in the oral cavity declines with time, thus compromising the resultant antimicrobial activity. It is, therefore, desirable to determine the persistence of the agent in the oral cavity by quantification of the drug concentration in saliva, thus enabling prediction of its antimicrobial activity in the oral environment. A rapid reverse-phase HPLC method was therefore developed and validated for Hexetidine in aqueous solution (Oraldene) and in saliva samples collected from volunteers post-rinsing with 15 mL of Hexetidine oral rinse for 30s. The HPLC assay was sufficiently sensitive to accurately detect Hexetidine in saliva up to 25 min after in-vivo use of a commercial oral rinse. Furthermore, it was possible to detect Hexetidine below the published minimum inhibitory concentrations (MICs) for a selection of microorganisms. From these data a first-order elimination rate constant of Hexetidine from the oral cavity was determined post-rinsing in each of six volunteers. The validated HPLC assay method presented is useful for the assay of Hexetidine in the oral cavity both at and below MICs. The first-order elimination rate constant shows significant variation between volunteers.
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The Effects of Hexetidine (Oraldene™) on the Adherence of Candida Albicans to Human Buccal Epithelial Cells In Vitro and Ex Vivo and on In Vitro Morphogenesis
Pharmaceutical Research, 1997Co-Authors: David S. Jones, James G. Mcgovern, A. David Woolfson, Sean P. GormanAbstract:Purpose . This study reports the effects of Hexetidine (Oraldene^™) on two virulence attributes of Candida albicans , namely, in vitro and ex vivo adherence of yeast cells to buccal epithelial cells (EEC) and in vitro morphogenesis. Methods . The effects of Hexetidine treatment of either yeast cells (stationary and exponential phases) or BEC on Candidal adherence, in terms of viable and non-viable adherent yeast cells, were evaluated using an acridine orange stain in conjunction with fluorescence microscopy. Ex vivo anti-adherence effects were determined by rinsing BEC in vivo with Hexetidine (0.1%), removal of BEC after defined periods and inclusion in the adherence assay. The effects of Hexetidine on morphogenesis were evaluated using light microscopy. Yeast cell viability following exposure to a range of concentration of Hexetidine (0.005-0.1 % v/v) for defined periods was determined following serial dilution and enumeration on solid media. Results . Treatment of stationary and exponential phase yeast cells or BEC with Hexetidine (0.1%) for a range of times (10−300 s) or, alternatively, with a range of concentrations of Hexetidine (0.005−0.1 %) for a fixed time (30s) significantly decreased the resultant Candidal / epithelial adhesion. No correlations were observed between reduced adherence and either time of treatment or Hexetidine concentration. In vivo treatment of BEC with Hexetidine (0.1%) for 30s resulted in prolonged and significant reductions in the ex vivo adherence of both viable and non-viable yeast cells for periods of up to (and including) four hours post-rinsing. Treatment of C. albicans blastospores with Hexetidine (0.05, 0.1% v/v) for 10s and 30s totally inhibited Candida morphogenesis, whereas treatment with lower antiseptic concentrations significantly reduced the extent of Candida morphogenesis and the rate of hyphal development. The effects of Hexetidine on yeast cell viability were both concentration and time-dependent. Conclusions . The reduced adherence of C. albicans to BEC and the modification or inhibition of morphogenesis following exposure to Hexetidine suggests a clinical role for Hexetidine in the prophylaxis of both superficial candidosis and the systemic complications resulting from invasion of sub-epithelial tissue.
A. David Woolfson - One of the best experts on this subject based on the ideXlab platform.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical Research, 2002Co-Authors: David S. Jones, James G. Mcgovern, A. David Woolfson, Colin G. Adair, Sean P. GormanAbstract:Purpose . Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence ( Staphylococcus aureus and Pseudomonas aeruginosa ). Methods . PVC emulsion was cured in the presence of Hexetidine (0-20% w/w) and was characterized in terms of drug release, surface properties (i.e., microrugosity/contact angle), mechanical (tensile) properties, and resistance to microbial adherence. Results . Under sink conditions, Hexetidine release from PVC was diffusion-controlled. Increasing the concentration of Hexetidine from 1% to 10% (w/w) (but not from 10% to 20% w/w) increased the subsequent rate of drug release. In general, increasing the concentration of Hexetidine decreased both the tensile properties and hydrophobicity, yet increased PVC microrugosity. Following Hexetidine release (21 days), the surface properties were similar to those of native PVC. The resistance of Hexetidine-containing PVC (1% or 5%) to microbial adherence (following defined periods of drug release) was greater than that of native PVC and was constant over the examined period of Hexetidine release. Conclusions . ET PVC containing 1% (w/w) Hexetidine offered an appropriate balance between suitable physicochemical properties and resistance to microbial adherence. This may offer an approach with which to reduce the incidence of ventilator-associated pneumonia.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical research, 2002Co-Authors: David S. Jones, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, Sean P. GormanAbstract:Purpose. Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence (Staphylococcus aureus and Pseudomonas aeruginosa).
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The concomitant development of poly(vinyl chloride)-related biofilm and antimicrobial resistance in relation to ventilator-associated pneumonia.
Biomaterials, 2001Co-Authors: Sean P. Gorman, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, David S. JonesAbstract:Abstract Ventilator-associated pneumonia is a major cause of death in intensive care patients and the endotracheal tube, commonly fabricated from poly(vinyl chloride) (PVC), is acknowledged as a significant factor in this. Bacteria colonise the biomaterial, thereby adopting a sessile mode of growth that progresses to the establishment of an antibiotic-resistant biofilm by the accretion of a protective glycocalyx. This study examined the sequential steps involved in the formation of biofilm on PVC by atomic force microscopy and the concomitant development of resistance to an antibiotic (ceftazidime) and to a non-antibiotic antimicrobial agent (Hexetidine). Staphylococcus aureus and Pseudomonas aeruginosa isolated from ET tube biofilm were employed. The surface microrugosity of bacteria growing in sessile mode on PVC decreased significantly ( p S. aureus were lower than for Ps. aeruginosa . Furthermore, sessile populations of S. aureus and Ps. aeruginosa on PVC exhibited greater resistance to both ceftazidime and Hexetidine when compared to planktonic bacterial growth. The efficacy of the agents, determined by kill kinetics, against sessile bacteria was dependent on age, with established biofilms (⩾24 h) significantly more resistant ( p p
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Determination of the salivary retention of Hexetidine in-vivo by high-performance liquid chromatography.
The Journal of pharmacy and pharmacology, 2000Co-Authors: Colin P. Mccoy, David S. Jones, Sean P. Gorman, J.g. Mcgovern, A. David WoolfsonAbstract:The non-antibiotic antimicrobial agent Hexetidine is widely used at a concentration of 0.1% w/v as an oral rinse to reduce the number of viable microorganisms within the oral cavity. However, following use, the available concentration of Hexetidine in the oral cavity declines with time, thus compromising the resultant antimicrobial activity. It is, therefore, desirable to determine the persistence of the agent in the oral cavity by quantification of the drug concentration in saliva, thus enabling prediction of its antimicrobial activity in the oral environment. A rapid reverse-phase HPLC method was therefore developed and validated for Hexetidine in aqueous solution (Oraldene) and in saliva samples collected from volunteers post-rinsing with 15 mL of Hexetidine oral rinse for 30s. The HPLC assay was sufficiently sensitive to accurately detect Hexetidine in saliva up to 25 min after in-vivo use of a commercial oral rinse. Furthermore, it was possible to detect Hexetidine below the published minimum inhibitory concentrations (MICs) for a selection of microorganisms. From these data a first-order elimination rate constant of Hexetidine from the oral cavity was determined post-rinsing in each of six volunteers. The validated HPLC assay method presented is useful for the assay of Hexetidine in the oral cavity both at and below MICs. The first-order elimination rate constant shows significant variation between volunteers.
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The Effects of Hexetidine (Oraldene™) on the Adherence of Candida Albicans to Human Buccal Epithelial Cells In Vitro and Ex Vivo and on In Vitro Morphogenesis
Pharmaceutical Research, 1997Co-Authors: David S. Jones, James G. Mcgovern, A. David Woolfson, Sean P. GormanAbstract:Purpose . This study reports the effects of Hexetidine (Oraldene^™) on two virulence attributes of Candida albicans , namely, in vitro and ex vivo adherence of yeast cells to buccal epithelial cells (EEC) and in vitro morphogenesis. Methods . The effects of Hexetidine treatment of either yeast cells (stationary and exponential phases) or BEC on Candidal adherence, in terms of viable and non-viable adherent yeast cells, were evaluated using an acridine orange stain in conjunction with fluorescence microscopy. Ex vivo anti-adherence effects were determined by rinsing BEC in vivo with Hexetidine (0.1%), removal of BEC after defined periods and inclusion in the adherence assay. The effects of Hexetidine on morphogenesis were evaluated using light microscopy. Yeast cell viability following exposure to a range of concentration of Hexetidine (0.005-0.1 % v/v) for defined periods was determined following serial dilution and enumeration on solid media. Results . Treatment of stationary and exponential phase yeast cells or BEC with Hexetidine (0.1%) for a range of times (10−300 s) or, alternatively, with a range of concentrations of Hexetidine (0.005−0.1 %) for a fixed time (30s) significantly decreased the resultant Candidal / epithelial adhesion. No correlations were observed between reduced adherence and either time of treatment or Hexetidine concentration. In vivo treatment of BEC with Hexetidine (0.1%) for 30s resulted in prolonged and significant reductions in the ex vivo adherence of both viable and non-viable yeast cells for periods of up to (and including) four hours post-rinsing. Treatment of C. albicans blastospores with Hexetidine (0.05, 0.1% v/v) for 10s and 30s totally inhibited Candida morphogenesis, whereas treatment with lower antiseptic concentrations significantly reduced the extent of Candida morphogenesis and the rate of hyphal development. The effects of Hexetidine on yeast cell viability were both concentration and time-dependent. Conclusions . The reduced adherence of C. albicans to BEC and the modification or inhibition of morphogenesis following exposure to Hexetidine suggests a clinical role for Hexetidine in the prophylaxis of both superficial candidosis and the systemic complications resulting from invasion of sub-epithelial tissue.
J.g. Mcgovern - One of the best experts on this subject based on the ideXlab platform.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical research, 2002Co-Authors: David S. Jones, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, Sean P. GormanAbstract:Purpose. Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence (Staphylococcus aureus and Pseudomonas aeruginosa).
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The concomitant development of poly(vinyl chloride)-related biofilm and antimicrobial resistance in relation to ventilator-associated pneumonia.
Biomaterials, 2001Co-Authors: Sean P. Gorman, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, David S. JonesAbstract:Abstract Ventilator-associated pneumonia is a major cause of death in intensive care patients and the endotracheal tube, commonly fabricated from poly(vinyl chloride) (PVC), is acknowledged as a significant factor in this. Bacteria colonise the biomaterial, thereby adopting a sessile mode of growth that progresses to the establishment of an antibiotic-resistant biofilm by the accretion of a protective glycocalyx. This study examined the sequential steps involved in the formation of biofilm on PVC by atomic force microscopy and the concomitant development of resistance to an antibiotic (ceftazidime) and to a non-antibiotic antimicrobial agent (Hexetidine). Staphylococcus aureus and Pseudomonas aeruginosa isolated from ET tube biofilm were employed. The surface microrugosity of bacteria growing in sessile mode on PVC decreased significantly ( p S. aureus were lower than for Ps. aeruginosa . Furthermore, sessile populations of S. aureus and Ps. aeruginosa on PVC exhibited greater resistance to both ceftazidime and Hexetidine when compared to planktonic bacterial growth. The efficacy of the agents, determined by kill kinetics, against sessile bacteria was dependent on age, with established biofilms (⩾24 h) significantly more resistant ( p p
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Determination of the salivary retention of Hexetidine in-vivo by high-performance liquid chromatography.
The Journal of pharmacy and pharmacology, 2000Co-Authors: Colin P. Mccoy, David S. Jones, Sean P. Gorman, J.g. Mcgovern, A. David WoolfsonAbstract:The non-antibiotic antimicrobial agent Hexetidine is widely used at a concentration of 0.1% w/v as an oral rinse to reduce the number of viable microorganisms within the oral cavity. However, following use, the available concentration of Hexetidine in the oral cavity declines with time, thus compromising the resultant antimicrobial activity. It is, therefore, desirable to determine the persistence of the agent in the oral cavity by quantification of the drug concentration in saliva, thus enabling prediction of its antimicrobial activity in the oral environment. A rapid reverse-phase HPLC method was therefore developed and validated for Hexetidine in aqueous solution (Oraldene) and in saliva samples collected from volunteers post-rinsing with 15 mL of Hexetidine oral rinse for 30s. The HPLC assay was sufficiently sensitive to accurately detect Hexetidine in saliva up to 25 min after in-vivo use of a commercial oral rinse. Furthermore, it was possible to detect Hexetidine below the published minimum inhibitory concentrations (MICs) for a selection of microorganisms. From these data a first-order elimination rate constant of Hexetidine from the oral cavity was determined post-rinsing in each of six volunteers. The validated HPLC assay method presented is useful for the assay of Hexetidine in the oral cavity both at and below MICs. The first-order elimination rate constant shows significant variation between volunteers.
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The effects of Hexetidine (Oraldene) on the adherence of Candida albicans to human buccal epithelial cells in vitro and ex vivo and on in vitro morphogenesis.
Pharmaceutical research, 1997Co-Authors: David S. Jones, A. David Woolfson, J.g. Mcgovern, Sean P. GormanAbstract:Purpose. This study reports the effects of Hexetidine (Oraldene™) on two virulence attributes of Candida albicans, namely,in vitro and ex vivoadherence of yeast cells to buccal epithelial cells (EEC) and in vitro morphogenesis.
Colin G. Adair - One of the best experts on this subject based on the ideXlab platform.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical Research, 2002Co-Authors: David S. Jones, James G. Mcgovern, A. David Woolfson, Colin G. Adair, Sean P. GormanAbstract:Purpose . Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence ( Staphylococcus aureus and Pseudomonas aeruginosa ). Methods . PVC emulsion was cured in the presence of Hexetidine (0-20% w/w) and was characterized in terms of drug release, surface properties (i.e., microrugosity/contact angle), mechanical (tensile) properties, and resistance to microbial adherence. Results . Under sink conditions, Hexetidine release from PVC was diffusion-controlled. Increasing the concentration of Hexetidine from 1% to 10% (w/w) (but not from 10% to 20% w/w) increased the subsequent rate of drug release. In general, increasing the concentration of Hexetidine decreased both the tensile properties and hydrophobicity, yet increased PVC microrugosity. Following Hexetidine release (21 days), the surface properties were similar to those of native PVC. The resistance of Hexetidine-containing PVC (1% or 5%) to microbial adherence (following defined periods of drug release) was greater than that of native PVC and was constant over the examined period of Hexetidine release. Conclusions . ET PVC containing 1% (w/w) Hexetidine offered an appropriate balance between suitable physicochemical properties and resistance to microbial adherence. This may offer an approach with which to reduce the incidence of ventilator-associated pneumonia.
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Physicochemical Characterization of Hexetidine-Impregnated Endotracheal Tube Poly(vinyl Chloride) and Resistance to Adherence of Respiratory Bacterial Pathogens
Pharmaceutical research, 2002Co-Authors: David S. Jones, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, Sean P. GormanAbstract:Purpose. Ventilator-associated pneumonia is a frequent cause of mortality in intensive care patients. This study describes the physicochemical properties of Hexetidine-impregnated poly(vinyl chloride) (PVC) endotracheal tube (ET) biomaterials and their resistance to microbial adherence (Staphylococcus aureus and Pseudomonas aeruginosa).
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The concomitant development of poly(vinyl chloride)-related biofilm and antimicrobial resistance in relation to ventilator-associated pneumonia.
Biomaterials, 2001Co-Authors: Sean P. Gorman, A. David Woolfson, Colin G. Adair, J.g. Mcgovern, David S. JonesAbstract:Abstract Ventilator-associated pneumonia is a major cause of death in intensive care patients and the endotracheal tube, commonly fabricated from poly(vinyl chloride) (PVC), is acknowledged as a significant factor in this. Bacteria colonise the biomaterial, thereby adopting a sessile mode of growth that progresses to the establishment of an antibiotic-resistant biofilm by the accretion of a protective glycocalyx. This study examined the sequential steps involved in the formation of biofilm on PVC by atomic force microscopy and the concomitant development of resistance to an antibiotic (ceftazidime) and to a non-antibiotic antimicrobial agent (Hexetidine). Staphylococcus aureus and Pseudomonas aeruginosa isolated from ET tube biofilm were employed. The surface microrugosity of bacteria growing in sessile mode on PVC decreased significantly ( p S. aureus were lower than for Ps. aeruginosa . Furthermore, sessile populations of S. aureus and Ps. aeruginosa on PVC exhibited greater resistance to both ceftazidime and Hexetidine when compared to planktonic bacterial growth. The efficacy of the agents, determined by kill kinetics, against sessile bacteria was dependent on age, with established biofilms (⩾24 h) significantly more resistant ( p p