This study aimed to develop niosomes of ellagic acid(EA),a potent antioxidant phytochemical substance,for dermal delivery and to investigate the influence of chemical penetration enhancers on the physicochemical prope...This study aimed to develop niosomes of ellagic acid(EA),a potent antioxidant phytochemical substance,for dermal delivery and to investigate the influence of chemical penetration enhancers on the physicochemical properties of EA-loaded niosomes.The EA niosomes were prepared by reverse phase evaporation method using Span 60,Tween 60 and cholesterol as vesicle forming agents and Solulan C24 as a steric stabilizer.Polyethylene glycol 400(PEG)was used as a solubilizer while dimethylsulfoxide(DMSO)or Nmethyl-2-pyrrolidone(NMP)was used as a skin penetration enhancer.It was found that the mean particle sizes of EA-loaded niosomes were in the range of 312e402 nm with PI values of lower than 0.4.The niosomes were determined to be spherical multilamellar vesicles as observed by transmission electron microscope and optical microscopy.All niosomes were stable after 4 months storage at 4C.In vitro skin permeation through human epidermis revealed that the skin enhancers affected the penetration of EA from the niosomes at 24 h.The DMSO niosomes showed the highest EA amount in epidermis;whereas the NMP niosomes had the highest EA amount in the acceptor medium.Concomitantly,the skin distribution by confocal laser scanning microscopy showed the high fluorescence intensity of the DMSO niosomes and NMP niosomes at a penetration depth of between 30e90 mm(the epidermis layer)and 90e120 mm(the dermis layer)under the skin,respectively.From the results,it can be concluded that the DMSO niosomes are suitable for epidermis delivery of EA while the NMP niosomes can be used for dermis delivery of EA.展开更多
In this paper we highlight how the apparent double coverage of toxins and bioregulators by both the Biological and Toxin Weapons Convention(BTWC)and the Chemical Weapons Convention(CWC)in fact masks a regulatory gap t...In this paper we highlight how the apparent double coverage of toxins and bioregulators by both the Biological and Toxin Weapons Convention(BTWC)and the Chemical Weapons Convention(CWC)in fact masks a regulatory gap that has left such potentially dangerous agents neglected by both the control regimes during a period of rapid advances in relevant chemical,life and associated sciences and technologies.We first review what toxins,bioregulators and other mid-spectrum agents are and why they are of such concern and then examine how they are regulated under the BTWC and CWC.This paper then examines an illustrative range of contemporary chemical and life science research and associated activities of concern drawn from case study research on China,India,Iran,Russia,Syria and the United States,and assesses how the CWC and BTWC States Parties have inadequately addressed these threats.We then examine how both the CWC and BTWC Review Conferences failed to address these long-term challenges,and we end by providing a series of recommendations for how both regimes can be strengthened in this area.展开更多
基金This project is supported by the Office of the High Education Commission and Mahidol University under the National Research Universities Initiative.
文摘This study aimed to develop niosomes of ellagic acid(EA),a potent antioxidant phytochemical substance,for dermal delivery and to investigate the influence of chemical penetration enhancers on the physicochemical properties of EA-loaded niosomes.The EA niosomes were prepared by reverse phase evaporation method using Span 60,Tween 60 and cholesterol as vesicle forming agents and Solulan C24 as a steric stabilizer.Polyethylene glycol 400(PEG)was used as a solubilizer while dimethylsulfoxide(DMSO)or Nmethyl-2-pyrrolidone(NMP)was used as a skin penetration enhancer.It was found that the mean particle sizes of EA-loaded niosomes were in the range of 312e402 nm with PI values of lower than 0.4.The niosomes were determined to be spherical multilamellar vesicles as observed by transmission electron microscope and optical microscopy.All niosomes were stable after 4 months storage at 4C.In vitro skin permeation through human epidermis revealed that the skin enhancers affected the penetration of EA from the niosomes at 24 h.The DMSO niosomes showed the highest EA amount in epidermis;whereas the NMP niosomes had the highest EA amount in the acceptor medium.Concomitantly,the skin distribution by confocal laser scanning microscopy showed the high fluorescence intensity of the DMSO niosomes and NMP niosomes at a penetration depth of between 30e90 mm(the epidermis layer)and 90e120 mm(the dermis layer)under the skin,respectively.From the results,it can be concluded that the DMSO niosomes are suitable for epidermis delivery of EA while the NMP niosomes can be used for dermis delivery of EA.
基金supported by an Emeritus Fellowship from the Leverhulme Trust(EM-2018-005/10)to Professor Malcolm Dando.
文摘In this paper we highlight how the apparent double coverage of toxins and bioregulators by both the Biological and Toxin Weapons Convention(BTWC)and the Chemical Weapons Convention(CWC)in fact masks a regulatory gap that has left such potentially dangerous agents neglected by both the control regimes during a period of rapid advances in relevant chemical,life and associated sciences and technologies.We first review what toxins,bioregulators and other mid-spectrum agents are and why they are of such concern and then examine how they are regulated under the BTWC and CWC.This paper then examines an illustrative range of contemporary chemical and life science research and associated activities of concern drawn from case study research on China,India,Iran,Russia,Syria and the United States,and assesses how the CWC and BTWC States Parties have inadequately addressed these threats.We then examine how both the CWC and BTWC Review Conferences failed to address these long-term challenges,and we end by providing a series of recommendations for how both regimes can be strengthened in this area.
