Peter McLoughlin - Academia.edu (original) (raw)
Papers by Peter McLoughlin
Journal of Applied Phycology, 2019
Biosecurity is emerging as one of the most important issues facing the agricultural and forestry ... more Biosecurity is emerging as one of the most important issues facing the agricultural and forestry communities, with the use of chemical pesticides being the main protocol for controlling plant pathogens. However, as a result of the emergence of resistance against these controls and the negative impact chemicals have on the environment, coupled with more stringent European Union regulations, this will have to change. The search for safer alternatives has begun, with seaweed becoming an interesting focus as a potential biopesticide due to its ability to produce a broad spectrum of chemically active secondary metabolites. These secondary metabolites possess biological properties including antimicrobial, antioxidant, anti-inflammatory, and antifungal. There is a need to develop reliable methods with the ability to rapidly screen and evaluate the potential pesticidal activity in seaweeds. This review focuses on the current methods used to investigate the fungicidal activity of seaweed extracts including in vitro methods namely disk diffusion and in vivo methods namely, the screen-house study and the advantages and disadvantages associated with each method. It was concluded that no one method is suitable for all test organisms or extracts after careful consideration of the literature. Additionally, this review confirms the promising potential of seaweeds as biopesticides with studies demonstrating that seaweeds are active against a wide variety of fungal diseases. It was noted that further research needs to be carried out on the isolation, purification, and identification of the bioactive compounds present in seaweeds in order to facilitate the future potential application of these novel biopesticides.
Poor aqueous solubility is a major challenge for formulation scientists as more than 40% of new c... more Poor aqueous solubility is a major challenge for formulation scientists as more than 40% of new chemical entities developed in the pharmaceutical industry are insoluble in water. The high energy am...
Mcloughlin Peter Atmospheric Reactions of Ethers and Ketones Phd Thesis Dublin City University, 1992
The Atm osphere and this thesis 2 1.2 References 24 Chapter 2.0 OH radical and Cl atom reactions ... more The Atm osphere and this thesis 2 1.2 References 24 Chapter 2.0 OH radical and Cl atom reactions with a series of ethers and ketones Page 3 .3 .4 P hotooxidation of the an ae sth etic s in th e 2 1 6 p res en c e of chlorine 3 .3 .5 Product studies 2 2 5 3.4 D iscu ssio n 242 3.5 C o n clu sio n 263 3.6 References 264
International Journal of Pharmaceutics, 2015
Inhalation formulations are a popular way of treating the symptoms of respiratory diseases. The a... more Inhalation formulations are a popular way of treating the symptoms of respiratory diseases. The active pharmaceutical ingredient (API) is delivered directly to the site of action within the deep lung using an inhalation device such as the dry powder inhaler (DPI). The performance of the formulation and the efficiency of the treatment depend on a number of factors including the forces acting between the components. In DPI formulations these forces are dominated by interparticulate interactions. Research has shown that adhesive and cohesive forces depend on a number of particulate properties such as size, surface roughness, crystallinity, surface energetics and combinations of these. With traditional methods the impact of particulate properties on interparticulate forces could be evaluated by examining the bulk properties. Atomic force microscopy (AFM), however, enables the determination of local surface characteristics and the direct measurement of interparticulate forces using the colloidal probe technique. AFM is considered extremely useful for evaluating the surface topography of a substrate (an API or carrier particle) and even allows the identification of crystal faces, defects and polymorphs from high-resolution images. Additionally, information is given about local mechanical properties of the particles and changes in surface composition and energetics. The assessment of attractive forces between two bodies is possible by using colloidal probe AFM. This review article summarises the application of AFM in DPI formulations while specifically focussing on the colloidal probe technique and the evaluation of interparticulate forces.
Environmental Pollution, 2012
This paper provides one of the most comprehensive studies of metal distributions in three main ma... more This paper provides one of the most comprehensive studies of metal distributions in three main macroalgae species. In this novel study, levels of total, intracellular and surface bound Pb, Zn, As, Cd, Co, Cr, Cu, Mn and Ni associated with Polysiphonia lanosa (L) Tandy, Ascophyllum nodosum (L) Le Jolis, Fucus vesiculosus (L) and Ulva sp. were determined. Additionally, water and sediment metal levels were analysed to gain an insight into the relative uptake efficiencies of different macroalgal species. Samples were collected from a clean site in Fethard-on-Sea, Wexford, Ireland (52 11 0 53.68 0 N, 6 49 0 34.64 0 W), in May 2008. Results demonstrated that total, intracellular and surface bound metal levels varied according to metal and seaweed species, with the highest proportion of metals found to be intracellular. Inhibition of Mn uptake by Zn was indicated for P. lanosa. Furthermore, P. lanosa had enhanced bioaccumulation ability, with the highest Concentration Factor reported of any seaweed to date.
Analytica Chimica Acta, 2005
The successful molecular imprinting of 2-aminopyridine (2-apy) in bulk polymerisations of acrylic... more The successful molecular imprinting of 2-aminopyridine (2-apy) in bulk polymerisations of acrylic and sol-gel based polymers has been achieved. Both polymeric systems reveal varying degrees of affinity in rebinding the original template as well as a number of structural analogues. Rebinding was conducted in chloroform, acetonitrile and methanol in order to assess the role of hydrogen bonding in imprinting. The acrylic imprinted polymer retained approximately 50% of the template in rebinding studies in chloroform compared to 100% for the sol-gel. However, this higher affinity for the sol-gel was accompanied by a higher degree of non-specific binding. While the acrylic polymer performed poorly in acetonitrile, the sol-gel maintained a high degree of discrimination. The acrylic polymer exhibited little discrimination between imprinted and reference polymers for 3-aminopyridine (3-apy) indicating the high selectivity of the MIP polymer for 2-apy relative to 3-apy. This selectivity was reduced in acetonitrile. Selectivity of the sol-gel for 2-apy in chloroform was poor as 3-apy was retained to a similar degree. Comparable results were obtained in acetonitrile. 4-Aminopyridine (4-apy) bound strongly to all polymers in all solvents and proved very difficult to remove due to the high degree of non-specific binding for both polymeric matrices.
Pharmaceutics
Extensive research is currently being conducted into novel ocular drug delivery systems (ODDS) th... more Extensive research is currently being conducted into novel ocular drug delivery systems (ODDS) that are capable of surpassing the limitations associated with conventional intraocular anterior and posterior segment treatments. Nanoformulations, including those synthesised from the natural, hydrophilic glycosaminoglycan, hyaluronic acid (HA), have gained significant traction due to their enhanced intraocular permeation, longer retention times, high physiological stability, inherent biocompatibility, and biodegradability. However, conventional nanoformulation preparation methods often require large volumes of organic solvent, chemical cross-linkers, and surfactants, which can pose significant toxicity risks. We present a comprehensive, critical review of the use of HA in the field of ophthalmology and ocular drug delivery, with a discussion of the physicochemical and biological properties of HA that render it a suitable excipient for drug delivery to both the anterior and posterior seg...
International Journal of Pharmaceutics
International Journal of Pharmaceutics
Investigative Ophthalmology & Visual Science, Jul 22, 2019
Pharmaceutics, 2021
Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the o... more Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the ocular surface caused by tear film dysfunction. Symptoms include dryness, irritation, discomfort and visual disturbance, and standard treatment includes the use of lubricants and topical steroids. Secondary inflammation plays a prominent role in the development and propagation of this debilitating condition. To address this we have investigated the pilot scale development of an innovative drug delivery system using a dexamethasone-encapsulated cholesterol-Labrafac™ lipophile nanostructured lipid carrier (NLC)-based ophthalmic formulation, which could be developed as an eye drop to treat DED and any associated acute exacerbations. After rapid screening of a range of laboratory scale pre-formulations, the chosen formulation was prepared at pilot scale with a particle size of 19.51 ± 0.5 nm, an encapsulation efficiency of 99.6 ± 0.5%, a PDI of 0.08, and an extended stability of 6 months at 4...
Pharmaceutics, 2021
Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the o... more Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the ocular surface caused by tear film dysfunction. Symptoms include dryness, irritation, discomfort and visual disturbance, and standard treatment includes the use of lubricants and topical steroids. Secondary inflammation plays a prominent role in the development and propagation of this debilitating condition. To address this we have investigated the pilot scale development of an innovative drug delivery system using a dexamethasone-encapsulated cholesterol-Labrafac™ lipophile nanostructured lipid carrier (NLC)-based ophthalmic formulation, which could be developed as an eye drop to treat DED and any associated acute exacerbations. After rapid screening of a range of laboratory scale pre-formulations, the chosen formulation was prepared at pilot scale with a particle size of 19.51 ± 0.5 nm, an encapsulation efficiency of 99.6 ± 0.5%, a PDI of 0.08, and an extended stability of 6 months at 4...
Pharmaceutics, 2021
The current treatment for the acquired retinal vasculopathies involves lifelong repeated intravit... more The current treatment for the acquired retinal vasculopathies involves lifelong repeated intravitreal injections of either anti-vascular endothelial growth factor (VEGF) therapy or modulation of inflammation with steroids. Consequently, any treatment modification that decreases this treatment burden for patients and doctors alike would be a welcome intervention. To that end, this research aims to develop a topically applied nanoparticulate system encapsulating a corticosteroid for extended drug release. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) supports the controlled release of the encapsulated drug, while surface modification of these NPs with chitosan might prolong the mucoadhesion ability leading to improved bioavailability of the drug. Triamcinolone acetonide (TA)-loaded chitosan-coated PLGA NPs were fabricated using the oil-in-water emulsion technique. The optimized surface-modified NPs obtained using Box-Behnken response surface statistical design were reprodu...
Scientific Reports, 2019
Antimicrobial resistant strains of infection are afflicting clinical settings, driving the search... more Antimicrobial resistant strains of infection are afflicting clinical settings, driving the search for novel antimicrobial compounds. Naturally sourced bioactives, for instance those from seaweeds, have the potential to ameliorate this issue. As such, solvent extracts from the edible Irish seaweeds Fucus serratus and Fucus vesiculosus were screened for antimicrobial activity against 28 clinically isolated strains of MRSA, including one GISA (glycopeptide intermediate S. aureus) and two mecC gene containing strains. The water extract of F. vesiculosus was the most promising extract went on to be tested for biofilm prevention and disruption activity. The disk diffusion method was used to investigate the inhibition of the bacterial pathogens tested while MIC, MBC and biofilm disruption and prevention analyses were performed spectroscopically and by plate counts, respectively. Solvent extracts were found to have a wide array of antimicrobial activity against the strains tested, with the ...
International journal of pharmaceutics, Jan 30, 2017
The highly effective barrier properties of the stratum corneum (SC) limit the application of tran... more The highly effective barrier properties of the stratum corneum (SC) limit the application of transdermal delivery to relatively small, lipophilic molecules. Microneedles (MNs) however, offer a route to effectively deliver a wide range of pharmaceuticals through the skin, bypassing the SC in a non-invasive and pain-free manner. This study presents a dissolving MN system composed of polyvinylpyrrolidone (PVP) and trehalose to encapsulate active pharmaceutical peptides within the MN matrix. Rapid systemic delivery is then achieved once the needles have penetrated the SC and dissolved in the interstitial fluid of the skin. A variety of characterisation techniques were carried out to determine the optimum formulation. A model peptide, polymyxin B, was then incorporated into the MN system and delivered through porcine skin. In addition, the activity of the model drug was monitored during all stages of the formulation process.
Plant and Animal Sources, 2013
Microchimica Acta, 2013
AbstractA comparative study was performed on different polymeric formats for targeting corticoste... more AbstractA comparative study was performed on different polymeric formats for targeting corticosteroids, focusing on the use of bulk monolith and precipitation polymerisation strategies. Hydrocortisone-17-butyrate was selected as the template and methacrylic acid as the functional monomer, following 1H NMR investigation of the pre-polymerisation mixture. Three different cross-linkers were tested, ranging from moderate to highly hydrophobic. The synthesised bulk and precipitated imprinted polymers were physically characterised by nitrogen sorption and evaluated by means of HPLC and frontal chromatography against a range of template analogues. While some degree of selectivity for the template was achieved for all tested polymers, the ones based on the tri-functional cross-linking monomer trimethylolpropane trimethacrylate exhibited the longest retention for all corticosteroids, especially in the precipitated format, which suggested broader group selectivity. FigureAn investigation into polymer format suitability for the molecular imprinting of corticosteroids.
Journal of Materials Chemistry, 2012
Molecularly Imprinted Polymers (MIPs) against S-ibuprofen were synthesised using a tailor made fu... more Molecularly Imprinted Polymers (MIPs) against S-ibuprofen were synthesised using a tailor made functional monomer, 2-acrylamido-4-methylpyridine, following extensive pre-polymerisation studies of template-monomer complexation. An apparent association constant of 340 AE 22 M À1 was calculated that was subsequently corrected to account for dimerisation of ibuprofen (K dim ¼ 320 AE 95 M À1) resulting in an intrinsic association constant of 715 AE 16 M À1 , consistent with previously reported values. Using the synthesised imprinted polymer as a stationary phase, complete resolution of a racemic mixture of ibuprofen was achieved in predominantly aqueous mobile phases. An imprinting factor of 10 was observed, and was found to be in agreement with the difference in the average number of binding sites between MIP and blank polymers, calculated by staircase frontal chromatography. The imprinted polymers exhibited enhanced selectivity for the templated drug over structurally related NSAIDs. When applied as sorbents in solid-phase extraction of ibuprofen from commercial tablets, urine and blood serum samples, recoveries up to 92.2% were achieved.
Analytical Methods, 2013
Molecularly Imprinted Polymers (MIPs) against imiquimod, a highly potent immune response modifier... more Molecularly Imprinted Polymers (MIPs) against imiquimod, a highly potent immune response modifier used in the treatment of skin cancer, were synthesised using a template analogue strategy and were compared with imprints of the drug itself. An investigation of the complexation between the functional monomer and the template analogue revealed an association constant of 1376 AE 122 M À1 , significantly higher than previously reported values for similar systems. The binding characteristics of the synthesised imprinted polymers were evaluated and extremely strong binding for imiquimod was observed while imprinting factors as high as 17 were calculated. When applied as sorbents in solid-phase extraction of imiquimod from aqueous, urine and blood serum samples, clean extracts and recoveries up to 95% were achieved, and it is concluded that while imiquimod imprints exhibited higher capacity for the drug, template analogue imprints are more selective. The results obtained suggest potential applications of imiquimod imprints as sorbents in rapid extraction and monitoring of undesirable systemic release of the drug.
Journal of Applied Phycology, 2019
Biosecurity is emerging as one of the most important issues facing the agricultural and forestry ... more Biosecurity is emerging as one of the most important issues facing the agricultural and forestry communities, with the use of chemical pesticides being the main protocol for controlling plant pathogens. However, as a result of the emergence of resistance against these controls and the negative impact chemicals have on the environment, coupled with more stringent European Union regulations, this will have to change. The search for safer alternatives has begun, with seaweed becoming an interesting focus as a potential biopesticide due to its ability to produce a broad spectrum of chemically active secondary metabolites. These secondary metabolites possess biological properties including antimicrobial, antioxidant, anti-inflammatory, and antifungal. There is a need to develop reliable methods with the ability to rapidly screen and evaluate the potential pesticidal activity in seaweeds. This review focuses on the current methods used to investigate the fungicidal activity of seaweed extracts including in vitro methods namely disk diffusion and in vivo methods namely, the screen-house study and the advantages and disadvantages associated with each method. It was concluded that no one method is suitable for all test organisms or extracts after careful consideration of the literature. Additionally, this review confirms the promising potential of seaweeds as biopesticides with studies demonstrating that seaweeds are active against a wide variety of fungal diseases. It was noted that further research needs to be carried out on the isolation, purification, and identification of the bioactive compounds present in seaweeds in order to facilitate the future potential application of these novel biopesticides.
Poor aqueous solubility is a major challenge for formulation scientists as more than 40% of new c... more Poor aqueous solubility is a major challenge for formulation scientists as more than 40% of new chemical entities developed in the pharmaceutical industry are insoluble in water. The high energy am...
Mcloughlin Peter Atmospheric Reactions of Ethers and Ketones Phd Thesis Dublin City University, 1992
The Atm osphere and this thesis 2 1.2 References 24 Chapter 2.0 OH radical and Cl atom reactions ... more The Atm osphere and this thesis 2 1.2 References 24 Chapter 2.0 OH radical and Cl atom reactions with a series of ethers and ketones Page 3 .3 .4 P hotooxidation of the an ae sth etic s in th e 2 1 6 p res en c e of chlorine 3 .3 .5 Product studies 2 2 5 3.4 D iscu ssio n 242 3.5 C o n clu sio n 263 3.6 References 264
International Journal of Pharmaceutics, 2015
Inhalation formulations are a popular way of treating the symptoms of respiratory diseases. The a... more Inhalation formulations are a popular way of treating the symptoms of respiratory diseases. The active pharmaceutical ingredient (API) is delivered directly to the site of action within the deep lung using an inhalation device such as the dry powder inhaler (DPI). The performance of the formulation and the efficiency of the treatment depend on a number of factors including the forces acting between the components. In DPI formulations these forces are dominated by interparticulate interactions. Research has shown that adhesive and cohesive forces depend on a number of particulate properties such as size, surface roughness, crystallinity, surface energetics and combinations of these. With traditional methods the impact of particulate properties on interparticulate forces could be evaluated by examining the bulk properties. Atomic force microscopy (AFM), however, enables the determination of local surface characteristics and the direct measurement of interparticulate forces using the colloidal probe technique. AFM is considered extremely useful for evaluating the surface topography of a substrate (an API or carrier particle) and even allows the identification of crystal faces, defects and polymorphs from high-resolution images. Additionally, information is given about local mechanical properties of the particles and changes in surface composition and energetics. The assessment of attractive forces between two bodies is possible by using colloidal probe AFM. This review article summarises the application of AFM in DPI formulations while specifically focussing on the colloidal probe technique and the evaluation of interparticulate forces.
Environmental Pollution, 2012
This paper provides one of the most comprehensive studies of metal distributions in three main ma... more This paper provides one of the most comprehensive studies of metal distributions in three main macroalgae species. In this novel study, levels of total, intracellular and surface bound Pb, Zn, As, Cd, Co, Cr, Cu, Mn and Ni associated with Polysiphonia lanosa (L) Tandy, Ascophyllum nodosum (L) Le Jolis, Fucus vesiculosus (L) and Ulva sp. were determined. Additionally, water and sediment metal levels were analysed to gain an insight into the relative uptake efficiencies of different macroalgal species. Samples were collected from a clean site in Fethard-on-Sea, Wexford, Ireland (52 11 0 53.68 0 N, 6 49 0 34.64 0 W), in May 2008. Results demonstrated that total, intracellular and surface bound metal levels varied according to metal and seaweed species, with the highest proportion of metals found to be intracellular. Inhibition of Mn uptake by Zn was indicated for P. lanosa. Furthermore, P. lanosa had enhanced bioaccumulation ability, with the highest Concentration Factor reported of any seaweed to date.
Analytica Chimica Acta, 2005
The successful molecular imprinting of 2-aminopyridine (2-apy) in bulk polymerisations of acrylic... more The successful molecular imprinting of 2-aminopyridine (2-apy) in bulk polymerisations of acrylic and sol-gel based polymers has been achieved. Both polymeric systems reveal varying degrees of affinity in rebinding the original template as well as a number of structural analogues. Rebinding was conducted in chloroform, acetonitrile and methanol in order to assess the role of hydrogen bonding in imprinting. The acrylic imprinted polymer retained approximately 50% of the template in rebinding studies in chloroform compared to 100% for the sol-gel. However, this higher affinity for the sol-gel was accompanied by a higher degree of non-specific binding. While the acrylic polymer performed poorly in acetonitrile, the sol-gel maintained a high degree of discrimination. The acrylic polymer exhibited little discrimination between imprinted and reference polymers for 3-aminopyridine (3-apy) indicating the high selectivity of the MIP polymer for 2-apy relative to 3-apy. This selectivity was reduced in acetonitrile. Selectivity of the sol-gel for 2-apy in chloroform was poor as 3-apy was retained to a similar degree. Comparable results were obtained in acetonitrile. 4-Aminopyridine (4-apy) bound strongly to all polymers in all solvents and proved very difficult to remove due to the high degree of non-specific binding for both polymeric matrices.
Pharmaceutics
Extensive research is currently being conducted into novel ocular drug delivery systems (ODDS) th... more Extensive research is currently being conducted into novel ocular drug delivery systems (ODDS) that are capable of surpassing the limitations associated with conventional intraocular anterior and posterior segment treatments. Nanoformulations, including those synthesised from the natural, hydrophilic glycosaminoglycan, hyaluronic acid (HA), have gained significant traction due to their enhanced intraocular permeation, longer retention times, high physiological stability, inherent biocompatibility, and biodegradability. However, conventional nanoformulation preparation methods often require large volumes of organic solvent, chemical cross-linkers, and surfactants, which can pose significant toxicity risks. We present a comprehensive, critical review of the use of HA in the field of ophthalmology and ocular drug delivery, with a discussion of the physicochemical and biological properties of HA that render it a suitable excipient for drug delivery to both the anterior and posterior seg...
International Journal of Pharmaceutics
International Journal of Pharmaceutics
Investigative Ophthalmology & Visual Science, Jul 22, 2019
Pharmaceutics, 2021
Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the o... more Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the ocular surface caused by tear film dysfunction. Symptoms include dryness, irritation, discomfort and visual disturbance, and standard treatment includes the use of lubricants and topical steroids. Secondary inflammation plays a prominent role in the development and propagation of this debilitating condition. To address this we have investigated the pilot scale development of an innovative drug delivery system using a dexamethasone-encapsulated cholesterol-Labrafac™ lipophile nanostructured lipid carrier (NLC)-based ophthalmic formulation, which could be developed as an eye drop to treat DED and any associated acute exacerbations. After rapid screening of a range of laboratory scale pre-formulations, the chosen formulation was prepared at pilot scale with a particle size of 19.51 ± 0.5 nm, an encapsulation efficiency of 99.6 ± 0.5%, a PDI of 0.08, and an extended stability of 6 months at 4...
Pharmaceutics, 2021
Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the o... more Dry eye disease (DED) or keratoconjunctivitis sicca is a chronic multifactorial disorder of the ocular surface caused by tear film dysfunction. Symptoms include dryness, irritation, discomfort and visual disturbance, and standard treatment includes the use of lubricants and topical steroids. Secondary inflammation plays a prominent role in the development and propagation of this debilitating condition. To address this we have investigated the pilot scale development of an innovative drug delivery system using a dexamethasone-encapsulated cholesterol-Labrafac™ lipophile nanostructured lipid carrier (NLC)-based ophthalmic formulation, which could be developed as an eye drop to treat DED and any associated acute exacerbations. After rapid screening of a range of laboratory scale pre-formulations, the chosen formulation was prepared at pilot scale with a particle size of 19.51 ± 0.5 nm, an encapsulation efficiency of 99.6 ± 0.5%, a PDI of 0.08, and an extended stability of 6 months at 4...
Pharmaceutics, 2021
The current treatment for the acquired retinal vasculopathies involves lifelong repeated intravit... more The current treatment for the acquired retinal vasculopathies involves lifelong repeated intravitreal injections of either anti-vascular endothelial growth factor (VEGF) therapy or modulation of inflammation with steroids. Consequently, any treatment modification that decreases this treatment burden for patients and doctors alike would be a welcome intervention. To that end, this research aims to develop a topically applied nanoparticulate system encapsulating a corticosteroid for extended drug release. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) supports the controlled release of the encapsulated drug, while surface modification of these NPs with chitosan might prolong the mucoadhesion ability leading to improved bioavailability of the drug. Triamcinolone acetonide (TA)-loaded chitosan-coated PLGA NPs were fabricated using the oil-in-water emulsion technique. The optimized surface-modified NPs obtained using Box-Behnken response surface statistical design were reprodu...
Scientific Reports, 2019
Antimicrobial resistant strains of infection are afflicting clinical settings, driving the search... more Antimicrobial resistant strains of infection are afflicting clinical settings, driving the search for novel antimicrobial compounds. Naturally sourced bioactives, for instance those from seaweeds, have the potential to ameliorate this issue. As such, solvent extracts from the edible Irish seaweeds Fucus serratus and Fucus vesiculosus were screened for antimicrobial activity against 28 clinically isolated strains of MRSA, including one GISA (glycopeptide intermediate S. aureus) and two mecC gene containing strains. The water extract of F. vesiculosus was the most promising extract went on to be tested for biofilm prevention and disruption activity. The disk diffusion method was used to investigate the inhibition of the bacterial pathogens tested while MIC, MBC and biofilm disruption and prevention analyses were performed spectroscopically and by plate counts, respectively. Solvent extracts were found to have a wide array of antimicrobial activity against the strains tested, with the ...
International journal of pharmaceutics, Jan 30, 2017
The highly effective barrier properties of the stratum corneum (SC) limit the application of tran... more The highly effective barrier properties of the stratum corneum (SC) limit the application of transdermal delivery to relatively small, lipophilic molecules. Microneedles (MNs) however, offer a route to effectively deliver a wide range of pharmaceuticals through the skin, bypassing the SC in a non-invasive and pain-free manner. This study presents a dissolving MN system composed of polyvinylpyrrolidone (PVP) and trehalose to encapsulate active pharmaceutical peptides within the MN matrix. Rapid systemic delivery is then achieved once the needles have penetrated the SC and dissolved in the interstitial fluid of the skin. A variety of characterisation techniques were carried out to determine the optimum formulation. A model peptide, polymyxin B, was then incorporated into the MN system and delivered through porcine skin. In addition, the activity of the model drug was monitored during all stages of the formulation process.
Plant and Animal Sources, 2013
Microchimica Acta, 2013
AbstractA comparative study was performed on different polymeric formats for targeting corticoste... more AbstractA comparative study was performed on different polymeric formats for targeting corticosteroids, focusing on the use of bulk monolith and precipitation polymerisation strategies. Hydrocortisone-17-butyrate was selected as the template and methacrylic acid as the functional monomer, following 1H NMR investigation of the pre-polymerisation mixture. Three different cross-linkers were tested, ranging from moderate to highly hydrophobic. The synthesised bulk and precipitated imprinted polymers were physically characterised by nitrogen sorption and evaluated by means of HPLC and frontal chromatography against a range of template analogues. While some degree of selectivity for the template was achieved for all tested polymers, the ones based on the tri-functional cross-linking monomer trimethylolpropane trimethacrylate exhibited the longest retention for all corticosteroids, especially in the precipitated format, which suggested broader group selectivity. FigureAn investigation into polymer format suitability for the molecular imprinting of corticosteroids.
Journal of Materials Chemistry, 2012
Molecularly Imprinted Polymers (MIPs) against S-ibuprofen were synthesised using a tailor made fu... more Molecularly Imprinted Polymers (MIPs) against S-ibuprofen were synthesised using a tailor made functional monomer, 2-acrylamido-4-methylpyridine, following extensive pre-polymerisation studies of template-monomer complexation. An apparent association constant of 340 AE 22 M À1 was calculated that was subsequently corrected to account for dimerisation of ibuprofen (K dim ¼ 320 AE 95 M À1) resulting in an intrinsic association constant of 715 AE 16 M À1 , consistent with previously reported values. Using the synthesised imprinted polymer as a stationary phase, complete resolution of a racemic mixture of ibuprofen was achieved in predominantly aqueous mobile phases. An imprinting factor of 10 was observed, and was found to be in agreement with the difference in the average number of binding sites between MIP and blank polymers, calculated by staircase frontal chromatography. The imprinted polymers exhibited enhanced selectivity for the templated drug over structurally related NSAIDs. When applied as sorbents in solid-phase extraction of ibuprofen from commercial tablets, urine and blood serum samples, recoveries up to 92.2% were achieved.
Analytical Methods, 2013
Molecularly Imprinted Polymers (MIPs) against imiquimod, a highly potent immune response modifier... more Molecularly Imprinted Polymers (MIPs) against imiquimod, a highly potent immune response modifier used in the treatment of skin cancer, were synthesised using a template analogue strategy and were compared with imprints of the drug itself. An investigation of the complexation between the functional monomer and the template analogue revealed an association constant of 1376 AE 122 M À1 , significantly higher than previously reported values for similar systems. The binding characteristics of the synthesised imprinted polymers were evaluated and extremely strong binding for imiquimod was observed while imprinting factors as high as 17 were calculated. When applied as sorbents in solid-phase extraction of imiquimod from aqueous, urine and blood serum samples, clean extracts and recoveries up to 95% were achieved, and it is concluded that while imiquimod imprints exhibited higher capacity for the drug, template analogue imprints are more selective. The results obtained suggest potential applications of imiquimod imprints as sorbents in rapid extraction and monitoring of undesirable systemic release of the drug.