The formulation and device collectively constitute an inhalation drug product.Development of inhaled drugs must consider the compatibility between formulation and device in order to achieve the intended pharmaceutical...The formulation and device collectively constitute an inhalation drug product.Development of inhaled drugs must consider the compatibility between formulation and device in order to achieve the intended pharmaceutical performance and usability of the product to improve patient compliance with treatment instruction.From the points of formulation,device and patient use,this article summarizes the inhalation drugs,including pressurized metered dose inhaler(pMDI),dry powder inhaler(DPI),and nebulizer that are currently available in the US and UK markets.It also discusses the practical considerations for the development of inhalers and provides an update on the corresponding regulations of the FDA(U.S.Food and Drug Administration)and the EMA(European Medicines Agency).展开更多
Water distribution network(WDN)leakage management has received increased attention in recent years.One of the most successful leakage-control strategies is to divide the network into District Metered Areas(DMAs).As a ...Water distribution network(WDN)leakage management has received increased attention in recent years.One of the most successful leakage-control strategies is to divide the network into District Metered Areas(DMAs).As a multi-staged technique,the generation of DMAs is a difficult task in design and implementation(i.e.,clustering,sectorization,and performance evaluation).Previous studies on DMAs implementation did not consider the potential use of existing valves in achieving the objective.In this work,a methodology is proposed for detecting clusters and reducing the cost of additional valves and DMA sectorization by considering existing valves as much as possible.The procedure of DMAs identification has been divided into three stages,i.e.,a)clusters identification;b)sectorization or boundaries optimization and c)performance evaluation of the partitioned network.The proposed methodology is evaluated on a simple network and a real-world water network with the findings provided and compared to the DMAs,established for a raw water network with no existing valves.It is found that there is an adequate difference in cost of strategy implementation in both the cases for the network under consideration and the existing valve system achieved better network performance in terms of resilience index.展开更多
The objective of the present work was to develop a metered dose transdermal spray(MDTS)formulation for transdermal delivery of testosterone and to characterize its efficacy.Testosterone release from a series of formul...The objective of the present work was to develop a metered dose transdermal spray(MDTS)formulation for transdermal delivery of testosterone and to characterize its efficacy.Testosterone release from a series of formulations was assessed in vitro.Skin from hairless mice was used in permeation experiments with Franz diffusion cells.The spray pattern,pump seal efficiency,average weight per metered dose and dose uniformity were evaluated.An optimized formulation containing 10%(w/v)testosterone,9%(v/v)azone and 91%(v/v)ethanol was based on good skin permeation and acceptable drug concentration and permeation enhancer(PE)content.A skin irritation study indicated that the formulation was non-irritating in a rat model.An in vivo pharmacokinetic study indicated that the optimized formulation showed a different plasma concentration-time profile from that of the commercially available product Testopatchs.The Testopatchs product demonstrated a more sustainable drug release.The evaluation of the testosterone MDTS indicated that it could deliver reproducible amounts of the formulation per actuation.The results obtained showed that the MDTS is a potential alternative therapeutic system for transdermal testosterone delivery.展开更多
The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles with...The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles within HFA 134a based metered dose formulations.Compositions of rizatriptan and scutellarin were spray-dried using different spray-drying parameters,and particles were suspended within HFA 134a.The surface morphology were determined using scanning electron microscopy(SEM),while the aerodynamic performance of MDIs was evaluated using a next generation pharmaceutical impactor.The surface morphology of spraydried particles could vary from smooth to moderately corrugated,and to raisin-like depending upon spray-drying parameters and preparation compositions.In general,increasing inlet temperature,decreasing feed concentration and/or adding leucine to the feed solution tended to increase the corrugated degree of particle surface.Deposition results indicated that raisinlike particle based MDIs for all compositions of the two drugs produced significantly better aerodynamic performance in terms of fine particle fractions and mass median aerodynamic diameters relative to the formulations of the corresponding smooth or slightly corrugated particles when the particle compositions were the same.The present results demonstrated that wrinkled particles increased fine particle fractions within surfactant-free MDI formulations.展开更多
文摘The formulation and device collectively constitute an inhalation drug product.Development of inhaled drugs must consider the compatibility between formulation and device in order to achieve the intended pharmaceutical performance and usability of the product to improve patient compliance with treatment instruction.From the points of formulation,device and patient use,this article summarizes the inhalation drugs,including pressurized metered dose inhaler(pMDI),dry powder inhaler(DPI),and nebulizer that are currently available in the US and UK markets.It also discusses the practical considerations for the development of inhalers and provides an update on the corresponding regulations of the FDA(U.S.Food and Drug Administration)and the EMA(European Medicines Agency).
文摘Water distribution network(WDN)leakage management has received increased attention in recent years.One of the most successful leakage-control strategies is to divide the network into District Metered Areas(DMAs).As a multi-staged technique,the generation of DMAs is a difficult task in design and implementation(i.e.,clustering,sectorization,and performance evaluation).Previous studies on DMAs implementation did not consider the potential use of existing valves in achieving the objective.In this work,a methodology is proposed for detecting clusters and reducing the cost of additional valves and DMA sectorization by considering existing valves as much as possible.The procedure of DMAs identification has been divided into three stages,i.e.,a)clusters identification;b)sectorization or boundaries optimization and c)performance evaluation of the partitioned network.The proposed methodology is evaluated on a simple network and a real-world water network with the findings provided and compared to the DMAs,established for a raw water network with no existing valves.It is found that there is an adequate difference in cost of strategy implementation in both the cases for the network under consideration and the existing valve system achieved better network performance in terms of resilience index.
基金supported financially by the Major Projects for Drug Innovation and Development from National Science and Technology(2012ZX09304004).
文摘The objective of the present work was to develop a metered dose transdermal spray(MDTS)formulation for transdermal delivery of testosterone and to characterize its efficacy.Testosterone release from a series of formulations was assessed in vitro.Skin from hairless mice was used in permeation experiments with Franz diffusion cells.The spray pattern,pump seal efficiency,average weight per metered dose and dose uniformity were evaluated.An optimized formulation containing 10%(w/v)testosterone,9%(v/v)azone and 91%(v/v)ethanol was based on good skin permeation and acceptable drug concentration and permeation enhancer(PE)content.A skin irritation study indicated that the formulation was non-irritating in a rat model.An in vivo pharmacokinetic study indicated that the optimized formulation showed a different plasma concentration-time profile from that of the commercially available product Testopatchs.The Testopatchs product demonstrated a more sustainable drug release.The evaluation of the testosterone MDTS indicated that it could deliver reproducible amounts of the formulation per actuation.The results obtained showed that the MDTS is a potential alternative therapeutic system for transdermal testosterone delivery.
基金the National Natural Science Foundation of China(grant no.81172997)the Ministry of Science and Technology of the People’s Republic of China(grant no.2012ZX09301-002-030)for the financial supports.
文摘The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles within HFA 134a based metered dose formulations.Compositions of rizatriptan and scutellarin were spray-dried using different spray-drying parameters,and particles were suspended within HFA 134a.The surface morphology were determined using scanning electron microscopy(SEM),while the aerodynamic performance of MDIs was evaluated using a next generation pharmaceutical impactor.The surface morphology of spraydried particles could vary from smooth to moderately corrugated,and to raisin-like depending upon spray-drying parameters and preparation compositions.In general,increasing inlet temperature,decreasing feed concentration and/or adding leucine to the feed solution tended to increase the corrugated degree of particle surface.Deposition results indicated that raisinlike particle based MDIs for all compositions of the two drugs produced significantly better aerodynamic performance in terms of fine particle fractions and mass median aerodynamic diameters relative to the formulations of the corresponding smooth or slightly corrugated particles when the particle compositions were the same.The present results demonstrated that wrinkled particles increased fine particle fractions within surfactant-free MDI formulations.
