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Frank J. Burczynski - One of the best experts on this subject based on the ideXlab platform.
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Metabolic Disposition of the Insect Repellent DEET and the Sunscreen Oxybenzone Following Intravenous and Skin Administration in Rats
2016Co-Authors: Daryl J. Fediuk, Tao Wang, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, Frank J. BurczynskiAbstract:Insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone have shown a synergistic percutaneous enhancement when applied concurrently. Both compounds are extensively metabolized in vivo into a series of potentially toxic metabolites: 2 metabolites of DEET, N,N-diethyl-m-hydroxymethylbenzamide (DHMB) and N-ethyl-m-toluamide (ET), and 3 metabolites of Oxybenzone, 2,4-dihydroxybenzophenone (DHB), 2,2-dihydroxy-4-methoxybenzophenone (DMB), and 2,3,4-trihydroxybenzophenone (THB). In this study, the metabolites were extensively distributed following intravenous and topical skin administration of DEET and Oxybenzone in rats. Combined application enhanced the disposition of all DEET metabolites in the liver but did not consistently affect the distribution of Oxybenzone metabolites. The DHMB appeared to be the major metabolite for DEET, while THB and its precursor DHB were the main metabolites for Oxybenzone. Repeated once-daily topical application for 30 days led to higher concentrations of DEET metabolites in the liver. Hepatoma cell studies revealed a decrease in cellular proliferation from all metabolites as single and combined treatments, most notably at 72 hours. Increased accumulation of DHMB and ET in the liver together with an ability to reduce cellular proliferation at achievable plasma concentrations indicated that simultaneous exposure to DEET and Oxybenzone might have the potential to precipitate adverse effects in a rat animal model
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Evaluation of percutaneous permeation of repellent DEET and sunscreen Oxybenzone from emulsion-based formulations in artificial membrane and human skin
Acta pharmaceutica Sinica. B, 2014Co-Authors: T.c. Wang, Donald W. Miller, Frank J. BurczynskiAbstract:Insect repellent DEET and sunscreen ingredient Oxybenzone play an essential role in minimizing vector-borne diseases and skin cancers. The purpose of this study was to investigate the effects of emulsion type, addition of thickening agent and droplet size in three emulsion-based lotions on percutaneous permeation of DEET and Oxybenzone using in vitro diffusion experiments, in order to minimize overall systemic permeation of the substances. Formulation C (water-in-oil emulsion) significantly increased overall permeation of DEET through human skin (56%) compared to Formulation A (oil-in-water emulsion). Formulation B (oil-in-water emulsion with thickening agent xanthan gum) significantly decreased the size of oil droplet containing DEET (16%), but no effect on oil droplets containing Oxybenzone. Adding xanthan gum also increased overall permeation of DEET and Oxybenzone (21% and 150%) when compared to Formulation A; presence of both ingredients in Formulation B further increased their permeation (36% and 23%) in comparison to its single counterparts. Overall permeation of Oxybenzone through LDPE was significantly higher by 26%–628% than that through human skin; overall permeation of DEET through human skin was significantly higher by 64%–338% than that through LDPE.
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Metabolic disposition of the insect repellent DEET and the sunscreen Oxybenzone following intravenous and skin administration in rats.
International journal of toxicology, 2012Co-Authors: Daryl J. Fediuk, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, T.c. Wang, Frank J. BurczynskiAbstract:Insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone have shown a synergistic percutaneous enhancement when applied concurrently. Both compounds are extensively metabolized in v...
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tissue disposition of the insect repellent deet and the sunscreen Oxybenzone following intravenous and topical administration in rats
Biopharmaceutics & Drug Disposition, 2011Co-Authors: Daryl J. Fediuk, Tao Wang, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, Frank J. BurczynskiAbstract:The insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone (OBZ) have been shown to produce synergistic permeation enhancement when applied concurrently in vitro and in vivo. The disposition of both compounds following intravenous administration (2 mg/kg of DEET or OBZ) and topical skin application (100 mg/kg of DEET and 40 mg/kg of OBZ) was determined in male Sprague-Dawley rats. Pharmacokinetic analysis was also conducted using compartmental and non-compartmental methods. A two-compartment model was deemed the best fit for intravenous administration. The DEET and Oxybenzone permeated across the skin to accumulate in blood, liver and kidney following topical skin application. Combined use of DEET and Oxybenzone accelerated the disappearance of both compounds from the application site, increased their distribution in the liver and significantly decreased the apparent elimination half-lives of both compounds (p < 0.05). Hepatoma cell studies revealed toxicity from exposure to all treatment concentrations, most notably at 72 h. Although DEET and Oxybenzone were capable of mutually enhancing their percutaneous permeation and systemic distribution from topical skin application, there was no evidence of increased hepatotoxic deficits from concurrent application. Copyright © 2011 John Wiley & Sons, Ltd.
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Tissue disposition of the insect repellent DEET and the sunscreen Oxybenzone following intravenous and topical administration in rats.
Biopharmaceutics & drug disposition, 2011Co-Authors: Daryl J. Fediuk, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, T.c. Wang, Frank J. BurczynskiAbstract:The insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone (OBZ) have been shown to produce synergistic permeation enhancement when applied concurrently in vitro and in vivo. The disposition of both compounds following intravenous administration (2 mg/kg of DEET or OBZ) and topical skin application (100 mg/kg of DEET and 40 mg/kg of OBZ) was determined in male Sprague-Dawley rats. Pharmacokinetic analysis was also conducted using compartmental and non-compartmental methods. A two-compartment model was deemed the best fit for intravenous administration. The DEET and Oxybenzone permeated across the skin to accumulate in blood, liver and kidney following topical skin application. Combined use of DEET and Oxybenzone accelerated the disappearance of both compounds from the application site, increased their distribution in the liver and significantly decreased the apparent elimination half-lives of both compounds (p
Vasilios G. Stavros - One of the best experts on this subject based on the ideXlab platform.
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Ultrafast photophysical studies of a multicomponent sunscreen: Oxybenzone–titanium dioxide mixtures
Chemical Physics Letters, 2016Co-Authors: Lewis A. Baker, Lucy C. Grosvenor, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Recent studies of the sunscreen constituent Oxybenzone have suggested that the dominant mechanism underlying the efficient photoprotection it offers relies on an initial ultrafast enol -> keto tautomerisation, followed by nonadiabatic transfer to the ground electronic state. Subsequent collisions with the solvent bath then reform the original enol tautomer. Utilising femtosecond transient electronic absorption spectroscopy we explore the dissipation of electronic excitation energy in Oxybenzone in the presence of titanium dioxide, a widely used, and complementary sunscreen component. We find the relaxation dynamics of this popular organic filter are unaltered by the presence of this favoured inorganic scatterer and the overall dynamics can be described by the additive contribution of the individual constituents. The combination of the two components provides broadband photoprotective properties justifying the widely used organic filter and inorganic scatterer mixtures in commercial sunscreen products.
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ultrafast photophysical studies of a multicomponent sunscreen Oxybenzone titanium dioxide mixtures
Chemical Physics Letters, 2016Co-Authors: Lewis A. Baker, Lucy C. Grosvenor, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Recent studies of the sunscreen constituent Oxybenzone have suggested that the dominant mechanism underlying the efficient photoprotection it offers relies on an initial ultrafast enol -> keto tautomerisation, followed by nonadiabatic transfer to the ground electronic state. Subsequent collisions with the solvent bath then reform the original enol tautomer. Utilising femtosecond transient electronic absorption spectroscopy we explore the dissipation of electronic excitation energy in Oxybenzone in the presence of titanium dioxide, a widely used, and complementary sunscreen component. We find the relaxation dynamics of this popular organic filter are unaltered by the presence of this favoured inorganic scatterer and the overall dynamics can be described by the additive contribution of the individual constituents. The combination of the two components provides broadband photoprotective properties justifying the widely used organic filter and inorganic scatterer mixtures in commercial sunscreen products.
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Broadband ultrafast photoprotection by Oxybenzone across the UVB and UVC spectral regions
Photochemical and Photobiological Sciences, 2015Co-Authors: Lewis A. Baker, Michael D. Horbury, Simon E. Greenough, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Recent studies have shed light on the energy dissipation mechanism of Oxybenzone, a common ingredient in commercial sunscreens. After UVA photoexcitation, the dissipation mechanism may be understood in terms of an initial ultrafast excited state enol → keto tautomerisation, followed by nonadiabatic transfer to the ground electronic state and subsequent collisional relaxation to the starting enol tautomer. We expand on these studies using femtosecond transient electronic absorption spectroscopy to understand the non-radiative relaxation pathways of Oxybenzone in cyclohexane and in methanol after UVB and UVC excitation. We find that the relaxation pathway may be understood in the same way as when exciting in the UVA region, concluding that Oxybenzone displays proficient broadband non-radiative photoprotection, and thus photophysically justifying its inclusion in sunscreen mixtures.
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Probing the Ultrafast Energy Dissipation Mechanism of the Sunscreen Oxybenzone after UVA Irradiation
Journal of Physical Chemistry Letters, 2015Co-Authors: Lewis A. Baker, Michael D. Horbury, Simon E. Greenough, Tolga N. V. Karsili, Philip M. Coulter, Gareth Roberts, Andrew J. Orr-ewing, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Oxybenzone is a common constituent of many commercially available sunscreens providing photoprotection from ultraviolet light incident on the skin. Femtosecond transient electronic and vibrational absorption spectroscopies have been used to investigate the nonradiative relaxation pathways of Oxybenzone in cyclohexane and methanol after excitation in the UVA region. The present data suggest that the photoprotective properties of Oxybenzone can be understood in terms of an initial ultrafast excited state enol → keto tautomerization, followed by efficient internal conversion and subsequent vibrational relaxation to the ground state (enol) tautomer.
Tao Wang - One of the best experts on this subject based on the ideXlab platform.
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Metabolic Disposition of the Insect Repellent DEET and the Sunscreen Oxybenzone Following Intravenous and Skin Administration in Rats
2016Co-Authors: Daryl J. Fediuk, Tao Wang, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, Frank J. BurczynskiAbstract:Insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone have shown a synergistic percutaneous enhancement when applied concurrently. Both compounds are extensively metabolized in vivo into a series of potentially toxic metabolites: 2 metabolites of DEET, N,N-diethyl-m-hydroxymethylbenzamide (DHMB) and N-ethyl-m-toluamide (ET), and 3 metabolites of Oxybenzone, 2,4-dihydroxybenzophenone (DHB), 2,2-dihydroxy-4-methoxybenzophenone (DMB), and 2,3,4-trihydroxybenzophenone (THB). In this study, the metabolites were extensively distributed following intravenous and topical skin administration of DEET and Oxybenzone in rats. Combined application enhanced the disposition of all DEET metabolites in the liver but did not consistently affect the distribution of Oxybenzone metabolites. The DHMB appeared to be the major metabolite for DEET, while THB and its precursor DHB were the main metabolites for Oxybenzone. Repeated once-daily topical application for 30 days led to higher concentrations of DEET metabolites in the liver. Hepatoma cell studies revealed a decrease in cellular proliferation from all metabolites as single and combined treatments, most notably at 72 hours. Increased accumulation of DHMB and ET in the liver together with an ability to reduce cellular proliferation at achievable plasma concentrations indicated that simultaneous exposure to DEET and Oxybenzone might have the potential to precipitate adverse effects in a rat animal model
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tissue disposition of the insect repellent deet and the sunscreen Oxybenzone following intravenous and topical administration in rats
Biopharmaceutics & Drug Disposition, 2011Co-Authors: Daryl J. Fediuk, Tao Wang, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, Frank J. BurczynskiAbstract:The insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone (OBZ) have been shown to produce synergistic permeation enhancement when applied concurrently in vitro and in vivo. The disposition of both compounds following intravenous administration (2 mg/kg of DEET or OBZ) and topical skin application (100 mg/kg of DEET and 40 mg/kg of OBZ) was determined in male Sprague-Dawley rats. Pharmacokinetic analysis was also conducted using compartmental and non-compartmental methods. A two-compartment model was deemed the best fit for intravenous administration. The DEET and Oxybenzone permeated across the skin to accumulate in blood, liver and kidney following topical skin application. Combined use of DEET and Oxybenzone accelerated the disappearance of both compounds from the application site, increased their distribution in the liver and significantly decreased the apparent elimination half-lives of both compounds (p < 0.05). Hepatoma cell studies revealed toxicity from exposure to all treatment concentrations, most notably at 72 h. Although DEET and Oxybenzone were capable of mutually enhancing their percutaneous permeation and systemic distribution from topical skin application, there was no evidence of increased hepatotoxic deficits from concurrent application. Copyright © 2011 John Wiley & Sons, Ltd.
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Percutaneous characterization of the insect repellent DEET and the sunscreen Oxybenzone from topical skin application
Toxicology and applied pharmacology, 2007Co-Authors: Sreeneeranj Kasichayanula, James D House, Tao WangAbstract:The synergistic percutaneous enhancement between insect repellent DEET and sunscreen Oxybenzone has been proven in our laboratory using a series of in vitro diffusion studies. In this study, we carried out an in vivo study to characterize skin permeation profiles from topical skin application of three commercially available repellent and sunscreen preparations. The correlation between skin disposition and drug metabolism was attempted by using data collected. Both DEET and Oxybenzone permeated across the skin after the application and achieved substantial systemic absorption. Combined use of DEET and Oxybenzone significantly enhanced the percutaneous penetration percentages (ranging 36-108%) due to mutual enhancement effects. Skin disposition indicated that DEET produced a faster transdermal permeation rate and higher systemic absorption extent, but Oxybenzone formed a concentrated depot within the skin and delivered the content slowly over the time. In vivo AUCP/MRT of DEET and Oxybenzone was increased by 37%/17% and 63%/10% when the two compounds were used together. No DEET was detected from the urine samples 48 h after the application. Tape stripping seemed to be a satisfactory approach for quantitative assessment of DEET and Oxybenzone penetration into the stratum corneum. It was also concluded that pharmacological and toxicological perspectives from concurrent application of insect repellent and sunscreen products require further evaluation to ensure use efficacy and safety of these common consumer healthcare products.
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In Vitro Percutaneous Permeation of the Repellent DEET and the Sunscreen Oxybenzone across Human Skin
Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, 2007Co-Authors: Tao Wang, Xiaochen GuAbstract:PURPOSE. DEET and Oxybenzone are two essential active ingredients in repellent and sunscreen products. The percutaneous permeation of the two compounds across human skin from five commercially available repellent and sunscreen products was investigated in vitro. METHODS. Diffusion studies were carried out at 37 °C, using Franz-style diffusion cells and human epidermis (380 µm in thickness). The test products were evaluated either individually or in various combinations for up to 6 hours. Concentrations of both compounds permeated through the skin were measured using an HPLC assay. Permeability and permeation percentage of DEET and Oxybenzone from different application approaches were calculated and statistically compared. RESULTS. The accumulated transdermal permeation was 0.5- 25.7% for DEET and 0.3-1.6% for Oxybenzone, respectively. Repellent lotion produced an 18-fold increase in transdermal permeation in comparison to that of repellent spray, while using repellent spray prior to sunscreen lotion resulted in the highest penetration of DEET among the study groups. Premixing sunscreen lotion with repellent spray at different ratios also produced significantly higher permeation of Oxybenzone across the skin than the control, but other application approaches did not differentiate from the single sunscreen lotion. CONCLUSION. It was concluded from this study that human skin was less permeable to DEET and Oxybenzone than artificial membranes, but was comparable to pig skin in permeability. DEET permeated transdermally more across human skin than Oxybenzone, and both compounds acted as permeation enhancers when used simultaneously. Premixing repellent and sunscreen enhanced the overall penetration of both DEET and Oxybenzone. Using different application sequences and amounts resulted in variable percutaneous permeation of DEET and Oxybenzone through the skin.
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In vitro permeation of repellent DEET and sunscreen Oxybenzone across three artificial membranes
International Journal of Pharmaceutics, 2006Co-Authors: Tao Wang, Sreeneeranj Kasichayanula, Xiaochen GuAbstract:DEET and Oxybenzone are two essential active ingredients in repellent and sunscreen products. We performed a series of in vitro diffusion studies to evaluate the transmembrane permeation of DEET and Oxybenzone across three artificial membranes, low-density polyethylene (LDPE), low fouling composite (LFC) and mixed cellulose esters (MCE), from concurrent use of commercial repellent and sunscreen preparations. Permeation of DEET and Oxybenzone across the test membranes was synergistically increased when both the repellent and the sunscreen formulations were applied simultaneously. Different application sequences and formulation types also resulted in variable permeation profiles of DEET and Oxybenzone. Compared to biological piglet epidermis under the identical experimental conditions, transmembrane permeation of DEET was suppressed in LDPE and LFC membranes, but enhanced in MCE membrane; transmembrane permeation of Oxybenzone was reduced in LFC membrane, but increased in LDPE and MCE membranes. Permeability coefficients of DEET and Oxybenzone in all three artificial membranes were significantly different from those in piglet skin. It was concluded that the permeation profiles of the compounds were dependent upon physicochemical characteristics of the membranes and the formulations.
Lewis A. Baker - One of the best experts on this subject based on the ideXlab platform.
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Ultrafast photophysical studies of a multicomponent sunscreen: Oxybenzone–titanium dioxide mixtures
Chemical Physics Letters, 2016Co-Authors: Lewis A. Baker, Lucy C. Grosvenor, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Recent studies of the sunscreen constituent Oxybenzone have suggested that the dominant mechanism underlying the efficient photoprotection it offers relies on an initial ultrafast enol -> keto tautomerisation, followed by nonadiabatic transfer to the ground electronic state. Subsequent collisions with the solvent bath then reform the original enol tautomer. Utilising femtosecond transient electronic absorption spectroscopy we explore the dissipation of electronic excitation energy in Oxybenzone in the presence of titanium dioxide, a widely used, and complementary sunscreen component. We find the relaxation dynamics of this popular organic filter are unaltered by the presence of this favoured inorganic scatterer and the overall dynamics can be described by the additive contribution of the individual constituents. The combination of the two components provides broadband photoprotective properties justifying the widely used organic filter and inorganic scatterer mixtures in commercial sunscreen products.
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ultrafast photophysical studies of a multicomponent sunscreen Oxybenzone titanium dioxide mixtures
Chemical Physics Letters, 2016Co-Authors: Lewis A. Baker, Lucy C. Grosvenor, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Recent studies of the sunscreen constituent Oxybenzone have suggested that the dominant mechanism underlying the efficient photoprotection it offers relies on an initial ultrafast enol -> keto tautomerisation, followed by nonadiabatic transfer to the ground electronic state. Subsequent collisions with the solvent bath then reform the original enol tautomer. Utilising femtosecond transient electronic absorption spectroscopy we explore the dissipation of electronic excitation energy in Oxybenzone in the presence of titanium dioxide, a widely used, and complementary sunscreen component. We find the relaxation dynamics of this popular organic filter are unaltered by the presence of this favoured inorganic scatterer and the overall dynamics can be described by the additive contribution of the individual constituents. The combination of the two components provides broadband photoprotective properties justifying the widely used organic filter and inorganic scatterer mixtures in commercial sunscreen products.
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Broadband ultrafast photoprotection by Oxybenzone across the UVB and UVC spectral regions
Photochemical and Photobiological Sciences, 2015Co-Authors: Lewis A. Baker, Michael D. Horbury, Simon E. Greenough, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Recent studies have shed light on the energy dissipation mechanism of Oxybenzone, a common ingredient in commercial sunscreens. After UVA photoexcitation, the dissipation mechanism may be understood in terms of an initial ultrafast excited state enol → keto tautomerisation, followed by nonadiabatic transfer to the ground electronic state and subsequent collisional relaxation to the starting enol tautomer. We expand on these studies using femtosecond transient electronic absorption spectroscopy to understand the non-radiative relaxation pathways of Oxybenzone in cyclohexane and in methanol after UVB and UVC excitation. We find that the relaxation pathway may be understood in the same way as when exciting in the UVA region, concluding that Oxybenzone displays proficient broadband non-radiative photoprotection, and thus photophysically justifying its inclusion in sunscreen mixtures.
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Probing the Ultrafast Energy Dissipation Mechanism of the Sunscreen Oxybenzone after UVA Irradiation
Journal of Physical Chemistry Letters, 2015Co-Authors: Lewis A. Baker, Michael D. Horbury, Simon E. Greenough, Tolga N. V. Karsili, Philip M. Coulter, Gareth Roberts, Andrew J. Orr-ewing, Michael N. R. Ashfold, Vasilios G. StavrosAbstract:Oxybenzone is a common constituent of many commercially available sunscreens providing photoprotection from ultraviolet light incident on the skin. Femtosecond transient electronic and vibrational absorption spectroscopies have been used to investigate the nonradiative relaxation pathways of Oxybenzone in cyclohexane and methanol after excitation in the UVA region. The present data suggest that the photoprotective properties of Oxybenzone can be understood in terms of an initial ultrafast excited state enol → keto tautomerization, followed by efficient internal conversion and subsequent vibrational relaxation to the ground state (enol) tautomer.
Daryl J. Fediuk - One of the best experts on this subject based on the ideXlab platform.
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Metabolic Disposition of the Insect Repellent DEET and the Sunscreen Oxybenzone Following Intravenous and Skin Administration in Rats
2016Co-Authors: Daryl J. Fediuk, Tao Wang, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, Frank J. BurczynskiAbstract:Insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone have shown a synergistic percutaneous enhancement when applied concurrently. Both compounds are extensively metabolized in vivo into a series of potentially toxic metabolites: 2 metabolites of DEET, N,N-diethyl-m-hydroxymethylbenzamide (DHMB) and N-ethyl-m-toluamide (ET), and 3 metabolites of Oxybenzone, 2,4-dihydroxybenzophenone (DHB), 2,2-dihydroxy-4-methoxybenzophenone (DMB), and 2,3,4-trihydroxybenzophenone (THB). In this study, the metabolites were extensively distributed following intravenous and topical skin administration of DEET and Oxybenzone in rats. Combined application enhanced the disposition of all DEET metabolites in the liver but did not consistently affect the distribution of Oxybenzone metabolites. The DHMB appeared to be the major metabolite for DEET, while THB and its precursor DHB were the main metabolites for Oxybenzone. Repeated once-daily topical application for 30 days led to higher concentrations of DEET metabolites in the liver. Hepatoma cell studies revealed a decrease in cellular proliferation from all metabolites as single and combined treatments, most notably at 72 hours. Increased accumulation of DHMB and ET in the liver together with an ability to reduce cellular proliferation at achievable plasma concentrations indicated that simultaneous exposure to DEET and Oxybenzone might have the potential to precipitate adverse effects in a rat animal model
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Metabolic disposition of the insect repellent DEET and the sunscreen Oxybenzone following intravenous and skin administration in rats.
International journal of toxicology, 2012Co-Authors: Daryl J. Fediuk, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, T.c. Wang, Frank J. BurczynskiAbstract:Insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone have shown a synergistic percutaneous enhancement when applied concurrently. Both compounds are extensively metabolized in v...
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tissue disposition of the insect repellent deet and the sunscreen Oxybenzone following intravenous and topical administration in rats
Biopharmaceutics & Drug Disposition, 2011Co-Authors: Daryl J. Fediuk, Tao Wang, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, Frank J. BurczynskiAbstract:The insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone (OBZ) have been shown to produce synergistic permeation enhancement when applied concurrently in vitro and in vivo. The disposition of both compounds following intravenous administration (2 mg/kg of DEET or OBZ) and topical skin application (100 mg/kg of DEET and 40 mg/kg of OBZ) was determined in male Sprague-Dawley rats. Pharmacokinetic analysis was also conducted using compartmental and non-compartmental methods. A two-compartment model was deemed the best fit for intravenous administration. The DEET and Oxybenzone permeated across the skin to accumulate in blood, liver and kidney following topical skin application. Combined use of DEET and Oxybenzone accelerated the disappearance of both compounds from the application site, increased their distribution in the liver and significantly decreased the apparent elimination half-lives of both compounds (p < 0.05). Hepatoma cell studies revealed toxicity from exposure to all treatment concentrations, most notably at 72 h. Although DEET and Oxybenzone were capable of mutually enhancing their percutaneous permeation and systemic distribution from topical skin application, there was no evidence of increased hepatotoxic deficits from concurrent application. Copyright © 2011 John Wiley & Sons, Ltd.
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Tissue disposition of the insect repellent DEET and the sunscreen Oxybenzone following intravenous and topical administration in rats.
Biopharmaceutics & drug disposition, 2011Co-Authors: Daryl J. Fediuk, Yufei Chen, Fiona E. Parkinson, Michael P. Namaka, Keith J. Simons, T.c. Wang, Frank J. BurczynskiAbstract:The insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone (OBZ) have been shown to produce synergistic permeation enhancement when applied concurrently in vitro and in vivo. The disposition of both compounds following intravenous administration (2 mg/kg of DEET or OBZ) and topical skin application (100 mg/kg of DEET and 40 mg/kg of OBZ) was determined in male Sprague-Dawley rats. Pharmacokinetic analysis was also conducted using compartmental and non-compartmental methods. A two-compartment model was deemed the best fit for intravenous administration. The DEET and Oxybenzone permeated across the skin to accumulate in blood, liver and kidney following topical skin application. Combined use of DEET and Oxybenzone accelerated the disappearance of both compounds from the application site, increased their distribution in the liver and significantly decreased the apparent elimination half-lives of both compounds (p
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Tissue Deposition of the Insect Repellent DEET and the Sunscreen Oxybenzone From Repeated Topical Skin Applications in Rats
International journal of toxicology, 2010Co-Authors: Daryl J. Fediuk, T.c. Wang, Joshua E. Raizman, Fiona E. ParkinsonAbstract:Insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen Oxybenzone are capable of enhancing skin permeation of each other when applied simultaneously. We carried out a cellular study in rat a...
