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Monolithic LC method applied to fesoterodine fumarate low dose extended-release tablets:Dissolution and release kinetics 被引量:2
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作者 Maximiliano S.Sangoi Vítor Todeschini Martin Steppe 《Journal of Pharmaceutical Analysis》 CAS 2015年第2期137-141,共5页
A dissolution test for fesoterodine low dose extended-release tablets using liquid chromatographic(LC) method equipped with a C18 monolithic column was developed and validated. LC system was operated isocratically a... A dissolution test for fesoterodine low dose extended-release tablets using liquid chromatographic(LC) method equipped with a C18 monolithic column was developed and validated. LC system was operated isocratically at controlled temperature(40 1C) using a mobile phase of acetonitrile:methanol:0.03 M ammonium acetate(p H 3.8)(30:15:55, v/v/v), run at a flow rate of 1.5 m L/min and detected at 208 nm. The best dissolution conditions for this formulation were achieved using a USP apparatus 2(paddle) at 100 rpm and 900 m L of phosphate buffer at p H 6.8 as the dissolution medium.Validation parameters such as the specificity, linearity, accuracy, precision, and robustness were evaluated according to international guidelines, giving results within the acceptable range. The kinetic parameters of drug release were also investigated using model-dependent methods and the dissolution profiles were best described by the Higuchi model. The validated dissolution test can be applied for quality control of this formulation. 展开更多
关键词 FESOTERODINE Dissolution test Low dose extendedrelease tablets Monolithic LC release kinetics
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Release Kinetics of Urea from Polymer Coated Urea and Its Relationship with Coating Penetrability
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作者 ZHANG Hai-jun, WU Zhi-jie, CHEN Li-jun and LIANG Wen-ju(Institute of Applied Ecology , Chinese Academy of Sciences , Shenyang 110016 , P. R. China) 《Agricultural Sciences in China》 CAS CSCD 2003年第11期1232-1238,共7页
Four kinds of polymer coated urea(PCU)were put in distilled water at 30℃ to determine the variation of coating penetrability and give a precise description of the urea release kinetics. The urea release from PCU coul... Four kinds of polymer coated urea(PCU)were put in distilled water at 30℃ to determine the variation of coating penetrability and give a precise description of the urea release kinetics. The urea release from PCU could be divided into four stages: lag stage, swell stage, steady stage and decay stage. The release rate coefficient K, a measure of coating penetrability, was linearly increased at swell stage, but almost not variable at steady stage. At decay stage, the relation of X to time t could be described by the equation K= mtn-1where m and n are the coefficients). When n>1, the coating penetrability was gradually increased, and the urea release from PCU was accelerated; when n=1, the coating penetrability was steady, and the urea release from PCU obeyed the first-order kinetics; and when n<1.the coating penetrability was gradually decreased, and the urea release from PCU was delayed, resulting in a significant 'tailing effect'. 展开更多
关键词 Polymer coated urea Urea release kinetics Coating penetrability FITTING
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Influence of Glutaraldehyde on the Properties and Release Kinetic of α-Tocopherol from Chitosan-based Film
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作者 Thanakorn YEAMSUKSAWAT Jun LIANG 《Agricultural Biotechnology》 CAS 2020年第1期85-88,95,共5页
A crosslinked chitosan film with α-tocopherol was produced by a solution casting method. The appearance, mechanical properties, morphology, barrier properties and release kinetics of the α-tocopherol were evaluated.... A crosslinked chitosan film with α-tocopherol was produced by a solution casting method. The appearance, mechanical properties, morphology, barrier properties and release kinetics of the α-tocopherol were evaluated. The addition of glutaraldehyde and α-tocopherol decreased the lightness and greenness and increased the yellowness of the chitosan-based film. Moreover, it also affected the compatibility of the film due to a decrease in the opacity values. The elongation at break(EB) and tensile strength(TS) values of the film decreased when the glutaraldehyde and α-tocopherol were added. In contrast, the Young’s modulus(YM) values increased. SEM micrographs showed coarse spots and pores on the surface and cross-section of the film when compared with the chitosan film. Based on the results, it was indicated that the chitosan structure was disconnected by the α-tocopherol, and the glutaraldehyde as a crosslinking agent generated a link between the chitosan network, which could be the cause of the reduced flexibility and the increased surface roughness of the film. However, the glutaraldehyde and α-tocopherol did not result in a significant difference in water vapour permeability(WVP) values. The glutaraldehyde influenced the release kinetics of the α-tocopherol as seen by the decrease of the diffusion coefficient values that were calculated using the Fickian diffusion model. 展开更多
关键词 release kinetic GLUTARALDEHYDE Α-TOCOPHEROL CHITOSAN Active film
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Effects of the kinetic pattern of dietary glucose release on nitrogen utilization, the portal amino acid profile, and nutrient transporter expression in intestinal enterocytes in piglets
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作者 Zexi Li Yunfei Li +6 位作者 Yufei Zhao Guifu Wang Rujie Liu Yue Li Qamar Aftab Zewei Sun Qingzhen Zhong 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第5期2106-2121,共16页
Background Promoting the synchronization of glucose and amino acid release in the digestive tract of pigs could effectively improve dietary nitrogen utilization.The rational allocation of dietary starch sources and th... Background Promoting the synchronization of glucose and amino acid release in the digestive tract of pigs could effectively improve dietary nitrogen utilization.The rational allocation of dietary starch sources and the exploration of appropriate dietary glucose release kinetics may promote the dynamic balance of dietary glucose and amino acid supplies.However,research on the effects of diets with different glucose release kinetic profiles on amino acid absorption and portal amino acid appearance in piglets is limited.This study aimed to investigate the effects of the kinetic pattern of dietary glucose release on nitrogen utilization,the portal amino acid profile,and nutrient transporter expression in intestinal enterocytes in piglets.Methods Sixty-four barrows(15.00±1.12 kg)were randomly allotted to 4 groups and fed diets formulated with starch from corn,corn/barley,corn/sorghum,or corn/cassava combinations(diets were coded A,B,C,or D respectively).Protein retention,the concentrations of portal amino acid and glucose,and the relative expression of amino acid and glucose transporter m RNAs were investigated.In vitro digestion was used to compare the dietary glucose release profiles.Results Four piglet diets with different glucose release kinetics were constructed by adjusting starch sources.The in vivo appearance dynamics of portal glucose were consistent with those of in vitro dietary glucose release kinetics.Total nitrogen excretion was reduced in the piglets in group B,while apparent nitrogen digestibility and nitrogen retention increased(P<0.05).Regardless of the time(2 h or 4 h after morning feeding),the portal total free amino acids content and contents of some individual amino acids(Thr,Glu,Gly,Ala,and Ile)of the piglets in group B were significantly higher than those in groups A,C,and D(P<0.05).Cluster analysis showed that different glucose release kinetic patterns resulted in different portal amino acid patterns in piglets,which decreased gradually with the extension of feeding time.The portal His/Phe,Pro/Glu,Leu/Val,Lys/Met,Tyr/Ile and Ala/Gly appeared higher similarity among the diet treatments.In the anterior jejunum,the glucose transporter SGLT1 was significantly positively correlated with the amino acid transporters B0AT1,EAAC1,and CAT1.Conclusions Rational allocation of starch resources could regulate dietary glucose release kinetics.In the present study,group B(corn/barley)diet exhibited a better glucose release kinetic pattern than the other groups,which could affect the portal amino acid contents and patterns by regulating the expression of amino acid transporters in the small intestine,thereby promoting nitrogen deposition in the body,and improving the utilization efficiency of dietary nitrogen. 展开更多
关键词 Glucose release kinetics Nitrogen utilization Nutrient transporter PIGLET
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Kinetics of Phosphate Release from Three Phosphate-Treated Soils 被引量:9
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作者 LI Shou-Tian ZHOU Jian-Min WANG Huo-Yan DU Chang-Wen CHEN Xiao-Qin 《Pedosphere》 SCIE CAS CSCD 2005年第4期518-525,共8页
Phosphate release from three selected soils after treatments of 1.6 and 2.4 mmol L-1 P was investigated using sequential extractions and fitted using six kinetic models, including zero order (Z), first order (F), seco... Phosphate release from three selected soils after treatments of 1.6 and 2.4 mmol L-1 P was investigated using sequential extractions and fitted using six kinetic models, including zero order (Z), first order (F), second order (S), parabolic diffusion (PD), two constant rate (TC), and Elovich type (ET) equations. The results showed that the rate of P release was initially rapid and then gradually declined with time. Also, P release increased with added P. Total P release followed the order: paddy soil with 2.4 mmol L-1 P > red soil with 2.4 mmol L-1 P > paddy soil with 1.6 mmol L-1 P > fluvo-aquic soil with 2.4 mmol L-1 P > fluvo-aquic with 1.6 mmol L-1 P > red soil with 1.6 mmol L-1 P. For the two P treatments P release from the paddy soils in the first extraction was 44.3% and 45.6% of total released P, respectively, which were higher than those from red and fluvo-aquic soils. The ratio of P release at the end of release time was 14.0% and 13.1% in the paddy soil treated with 1.6 and 2.4 mmol L-1 P, respectively, but only 5.1% and 9.2% in the red soil and 7.0% and 5.2% in the fluvo-aquic soil, respectively. Comparison of the coefficients of determination (R2) indicated that ET, TC, and PD equations could describe the P release data better than Z, F, and S equations. 展开更多
关键词 fluvo-aquic soil paddy soil PHOSPHATE red soil release kinetics
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Characterization and mapping of the multi-component release kinetics of a Traditional Chinese Medicine dosage form using a modified LC/MS/MS method and chemomic release kinetic theory 被引量:3
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作者 Hai-yan Li Xiang-yong Cui +7 位作者 Feng Gao Peter York Qun Shao Xian-zhen Yin Tao Guo Zhen Guo Jing-kai Gu Ji-wen Zhang 《Acta Pharmaceutica Sinica B》 SCIE CAS 2011年第2期106-114,共9页
It is essential to develop effective methods for the quality control of the traditional medicine with multiple components.However,few researches on the quality control have been conducted to interpret the holistic cha... It is essential to develop effective methods for the quality control of the traditional medicine with multiple components.However,few researches on the quality control have been conducted to interpret the holistic characteristics of the traditional medicine in terms of dissolution/release.In this study,the multi-component release kinetics of Traditional Chinese Medicine(TCM)dosage forms was characterized and mapped by multivariate analysis techniques in the field of‘‘-omics’’.The Liuweidihuang pill was used as a model formulation.The multi-component release kinetics of the concentrated and water-honeyed Liuweidihuang pills at rotation speeds of 50 and 100 rpm were analyzed by chemomic release kinetic theory and modified LC/MS/MS method.Mass features of 103(concentrated pills)and 101(water-honeyed pills)were selected with a linear correlation coefficient Z0.99 between mass responses and concentrations.To compose the chemomic standard spectrum,the relative abundance of both mass features was no less than 1%as compared with an internal standard.The correlation coefficients between six samples of various solutions were in line with analytical requirements of precision(rZ0.985).The score plots of principal component analysis showed that the concentrated Liuweidihuang pills presented better chemomic release reproducibility than the water-honeyed pills.Conversely,the impact of rotation speed on the chemomic release was less obvious.The heat maps of hierarchical clustering analysis did not show significant changes in individual clusters of mass features along different time intervals,reflecting the release integrity of the mass features.Therefore,both multivariate analysis methods,the principal component analysis and the hierarchical clustering analysis,seemed to be effective techniques to demonstrate the multiple component release performance of TCM.The research provided the basis of a new strategy for the quality control procedures of the dissolution/release for the traditional medicine and multi-component natural products to address increasing regulatory requirements and scrutiny across the world. 展开更多
关键词 Chemomic release kinetics Liuweidihuang pills Principal component analysis Hierarchical clustering analysis MULTI-COMPONENT
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Relationship between dietary amino acid release kinetics and nitrogen deposition in growing pigs 被引量:1
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作者 Qiyu Zhang Bin Wang +4 位作者 Nianzhi Hu Nan Bao Li Pan Yuan Zhao Guixin Qin 《Animal Nutrition》 SCIE CSCD 2022年第2期233-239,共7页
Although the protein content of swine diets is formulated based on the ileal digestibility of protein and amino acids(AA)under current nutrition requirements,the nitrogen utilization efficiency of swine varies based o... Although the protein content of swine diets is formulated based on the ileal digestibility of protein and amino acids(AA)under current nutrition requirements,the nitrogen utilization efficiency of swine varies based on protein source,which may be related to AA release kinetics.In this experiment,a 2×2 factorial arrangement with casein(CAS)-enriched or corn gluten meal(CGM)-enriched protein sources at different digestible crude protein levels(normal[N],13%;and low[L],11%)were applied to 24 crossbred(DurocLandraceYorkshire)growing pigs(average body weight=43.3±3.5 kg)in 4 treatments(N.CAS,L.CAS,N.CGM,L.CGM,respectively)to investigate the effects of AA release kinetics on nitrogen deposition in growing pigs.Standardized ileal digestible AA in all diets were balanced by adding individual AA to meet the nutrient requirements.The AA release kinetics were detected in vitro by measuring the hydrolysis of various protein diets under pepsin and trypsin conditions.The results demonstrated that the time of AA release peak in the CGM diet was 12 h later than that in the CAS diet.The synchronization indices of dietary AA release in N.CAS,N.CGM,L.CAS,and L.CGM were 23.73%,29.37%,23.40%,and 26.07%,respectively.The N.CGM had the poorest AA release synchronism while the N.CAS had the greatest among the 4 diets.However,within the pigs,L.CAS and N.CGM showed the highest(81.08%)and lowest(73.54%)nitrogen biological values,respectively,despite the standard ileal digestible AA levels being equal for all diets.These results indicate that the release kinetics of dietary AA had great effect on nitrogen deposition.To optimize nitrogen deposition,AA release kinetics and composition should be taken into consideration when formulating diets for growing pigs. 展开更多
关键词 Amino acid Growing pig Nitrogen deposition release kinetics SYNCHRONIZATION
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Study on Sustained-Release Pesticides Blended with Fosthiazate-Stearic Acid/Expanded Perlite
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作者 Huimin Huang Zijun Wu +3 位作者 Zhijian Zhou Qiulin Xu Jie Yan Qiaoguang Li 《Journal of Renewable Materials》 SCIE EI 2023年第1期257-272,共16页
The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release con... The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release control abil-ity is an effective method to realize effective utilization of pesticides and reduce pesticide losses.In this work,fosthiazate-stearic acid/expanded perlite sustained-release particles were successfully prepared by vacuum impregnation using expanded perlite(EP)as carrier,fosthiazate(FOS)as model pesticide and stearic acid(SA)as hydrophobic matrix.The structure and morphology of the samples were studied by BET,FT-IR,TGA,XRD,DSC and SEM.The effects of different mass ratios of FOS to SA on loading capacity and release rate at 24 h were investigated.The sustained release behavior of FOS-SA/EP at different temperatures and pH values was investigated by static dialysis bag method.The results showed that FOS and SA were adsorbed in EP pores by physical interaction.With the mass ratios of FOS to SA decreasing from 7:3 to 3:7,the 24 h release rate of FOS-SA/EP decreased from 18.77%to 8.05%,and the drug loading decreased from 461.32 to 130.99 mg/g.FOS-SA/EP showed obvious temperature response at 25℃,30℃ and 35℃,the cumulative release rate(CRR)of 200 h were 33.38%,41.50%and 51.17%,respectively.When pH=5,the CRR of FOS was higher than that of pH=7,and the CRR of FOS for 200 h were 49.01%and 30.12%,respectively.At different temperatures and pH=5,the release mechanism of FOS-SA/EP belongs to the Fickian diffusion mechanism;When pH=7,the diffusion mechanism is dominant,and the dissolution mechanism is complementary. 展开更多
关键词 Expanded perlite FOSTHIAZATE stearic acid sustained release release kinetics
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Release Characteristics of Different N Forms in an Uncoated Slow/Controlled Release Compound Fertilizer 被引量:14
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作者 DONG Yan WANG Zheng-yin 《Agricultural Sciences in China》 CAS CSCD 2007年第3期330-337,共8页
This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer (UCRF) and the N uptake and N-use efficiency by rice plants. Water dissolution, soil le... This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer (UCRF) and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations: the first-order kinetics equation [N1=N0 (1-e^-kt)], Elovich equation (N1=a + blnt), and parabola equation (N1=a + bt^0.5), with the best fitting by the first-order kinetics equation for different N (r= 0.9569^**-0.9999^**). The release potentials (No values estimated by the first-order kinetics equation) of different N in the UCRF decreased in the order of total N 〉 DON 〉 urea-N 〉 NH4^+-N 〉 NO3^-N in water, and total N 〉 NH4^+-N 〉 DON 〉 urea-N 〉 NO3^--N in soil, respectively, being in accordance with cumulative amounts of N release. The constants of N release rate (k values and b values) for different N forms were in decreasing order of total N 〉 DON 〉 NH4^+-N 〉 NO3^--N in water, whereas the k values were urea- N 〉DON 〉 NH4^+-N 〉 total N 〉 NO3^--N, and the b values were total N 〉 NH4^+-N 〉 DON 〉 NO3^--N 〉 urea-N in soil. Compared with a common compound fertilizer, the N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg^-1, and 5.17 kg kg^-1, respectively. The ratios of different N to total N in the UCRF showed significant correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt=N0 (l-e^kt)] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form. 展开更多
关键词 slow/controlled release compound fertilizer nitrogen forms release kinetics nitrogen use efficiency
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Chlorogenic acid loaded chitosan nanoparticles with sustained release property,retained antioxidant activity and enhanced bioavailability 被引量:7
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作者 Ilaiyaraja Nallamuthu Aishwarya Devi Farhath Khanum 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2015年第3期203-211,共9页
In this study,chlorogenic acid(CGA),a phenolic compound widely distributed in fruits and vegetables,was encapsulated into chitosan nanoparticles by ionic gelation method.The particles exhibited the size and zeta poten... In this study,chlorogenic acid(CGA),a phenolic compound widely distributed in fruits and vegetables,was encapsulated into chitosan nanoparticles by ionic gelation method.The particles exhibited the size and zeta potential of 210 nm and 33 mV respectively.A regular,spherical shaped distribution of nanoparticles was observed through scanning electron microscopy(SEM)and the success of entrapment was confirmed by FTIR analysis.The encapsulation efficiency of CGA was at about 59%with the loading efficiency of 5.2%.In vitro ABTS assay indicated that the radical scavenging activity of CAG was retained in the nanostructure and further,the release kinetics study revealed the burst release of 69%CGA from nanoparticles at the end of 100th hours.Pharmacokinetic analysis in rats showed a lower level of Cmax,longer Tmax,longer MRT,larger AUC0et and AUC0e∞for the CGA nanoparticles compared to free CGA.Collectively,these results suggest that the synthesised nanoparticle with sustained release property can therefore ease the fortification of food-matrices targeted for health benefits through effective delivery of CGA in body. 展开更多
关键词 Chlorogenic acid CHITOSAN NANOENCAPSULATION Antioxidant activity In vitro release kinetics Pharmacokinetic analysis
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Taste masking of ciprofloxacin by ion-exchange resin and sustain release at gastric-intestinal through interpenetrating polymer network 被引量:2
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作者 A.Michael Rajesh Shreya A.Bhatt +2 位作者 Harshad Brahmbhatt Pritpal Singh Anand Kiritkumar Mangaldas Popat 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2015年第4期331-340,共10页
The aim of the study was to taste mask ciprofloxacin(CP)by using ion-exchange resins(IERs)followed by sustain release of CP by forming interpenetrating polymer network(IPN).IERs based on the copolymerization of acryli... The aim of the study was to taste mask ciprofloxacin(CP)by using ion-exchange resins(IERs)followed by sustain release of CP by forming interpenetrating polymer network(IPN).IERs based on the copolymerization of acrylic acid with different cross linking agents were synthesised.Drug-resin complexes(DRCs)with three different ratios of drug to IERs(1:1,1:2,1:4)were prepared&evaluated for taste masking by following in vivo and in vitro methods.Human volunteers graded ADC 1:4,acrylic acid-divinyl benzene(ADC-3)resin as tasteless.Characterization studies such as FTIR,SEM,DSC,P-XRD differentiated ADC 1:4,from physical mixture(PM 1:4)and confirmed the formation of complex.In vitro drug release of ADC 1:4 showed complete release of CP within 60 min at simulated gastric fluid(SGF)i.e.pH 1.2.IPN beads were prepared with ADC 1:4 by using sodium alginate(AL)and sodium alginate-chitosan(AL-CS)for sustain release of CP at SGF pH and followed by simulated intestinal fluid(SIF i.e.pH 7.4).FTIR spectra confirmed the formation of IPN beads.The release of CP was sustain at SGF pH(<20%)whereas in SIF media it was more(>75%).The kinetic model of IPN beads showed the release of CP was non-Fickian diffusion type. 展开更多
关键词 Ion exchange resins Biopolymers In vitro&in vivo taste masking CIPROFLOXACIN Sustain release release mechanism and kinetics
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Bovine Serum Albumin (BSA) Microspheres Containing Methotrexate (MTX) I.Pharmaceutical Aspects
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作者 石庭森 陈小平 《Journal of Chinese Pharmaceutical Sciences》 CAS 1993年第1期33-38,共6页
Microspheres Ⅰ,Ⅱ and Ⅲ were produced by emulsion technique.Microsphere I was solidified by glutaraldehyde crosslinking,microsphere Ⅱ was solidified by glutaraldehyde crosslinking and further treated with glycine s... Microspheres Ⅰ,Ⅱ and Ⅲ were produced by emulsion technique.Microsphere I was solidified by glutaraldehyde crosslinking,microsphere Ⅱ was solidified by glutaraldehyde crosslinking and further treated with glycine solution and microsphere Illwas solidified by heating denaturation only.The results showed that the microsphere diameter produced by cross[inking was bigger than that prepared by heating.The microsphere Ⅱ had higher hydrophilicity than Microsphere I had.The methotrexate (MTX) contents in microspheres Ⅰ and Ⅱ were 2.73±0.053%,2.87±0.119% respectively. microsphere Ⅲ was only blank microspheres with MTX adsorbed on their surfaces.In vitro release studies,microspheres I and I have maintained sustained release of MTX till the next day,it was found that the drug releases from microspheres Ⅰ and Ⅱ were governed by Higuchi diffusion law. 展开更多
关键词 Hydrophillic albumin microspheres Emulsion technique METHOTREXATE Drug release kinetics
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The effect of low-molecular-weight organic-acids(LMWOAs)on treatment of chromium-contaminated soils by compost-phytoremediation: Kinetics of the chromium release and fractionation 被引量:8
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作者 Huixia Chen Junfeng Dou Hongbin Xu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第8期45-53,共9页
A soil–plant biological system was developed from chromium(Cr) polluted soil treated by the compost-phytoremediation method. The transformation and migration of the Cr in this system is comprehensively studied in t... A soil–plant biological system was developed from chromium(Cr) polluted soil treated by the compost-phytoremediation method. The transformation and migration of the Cr in this system is comprehensively studied in this research. The results illustrated that the co-composting treatment can reduce the Cr availability from 39%(F1 was about 31% of total, F2 was about 8% of total) to less than 2% by stabilizing the Cr. However, herbaceous plants can accumulate the concentrations of Cr from 113.8 to 265.2 mg/kg in the two crops,even though the concentration of soluble Cr in the substrate soil was below 0.1 mg/L.Cr can be assimilated and easily transferred in the tissues of plants because the lowmolecular-weight organic-acids(LMWOAs) derived from the plant root increase the bioavailability of Cr. The amount of extracted Cr dramatically increased when the organic acids were substituted in this order: citric acid 〉 malic acid 〉 tartaric acid 〉 oxalic acid 〉acetic acid. On average the maximum(147.4 mg/kg) and the minimum(78.75 mg/kg) Cr were extracted by 20 mmol/L citric acid and acetic acid, respectively. The desorption of Cr in different acid solutions can be predicted by the pseudo second-order kinetics. The exchangeable Cr, carbonate-bound Cr, and residual Cr decreased, while Fe–Mn oxide bound Cr and organic bound Cr increased in the soil solid phase. According to the experimental results, the organic acids will promote the desorption and chelation processes of Cr, leading to the remobilization of Cr in the soil. 展开更多
关键词 CHROMIUM PHYTOEXTRACTION Desorption release kinetics Speciation
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Current sustained delivery strategies for the design of local neurotrophic factors in treatment of neurological disorders 被引量:2
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作者 Hongzhuo Liu Yanyan Zhou +3 位作者 Shichao Chen Meng Bu Jiayu Xin Sanming Li 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2013年第5期269-277,共9页
Although therapeutic potential of neurotrophic factors(NTFs)has been well recognized for over two decades,attempts to translate that potential to the clinic have been disappointing,largely due to significant obstacle... Although therapeutic potential of neurotrophic factors(NTFs)has been well recognized for over two decades,attempts to translate that potential to the clinic have been disappointing,largely due to significant obstacles in delivery,including inadequate protein dose/kinetics released at target sites.Considerable efforts have been made to improve the therapeutic performance of NTFs.This articles reviews recent developments in localized delivery systems of NTFs for the neurological disorders treatments with a main focus on sustained delivery strategies.Different non-covalent binding approaches have been employed to immobilize proteins in hydrogels,microspheres,electrospun nanofibers,and their combined systems,which serve as depots for sustained local release of NTFs.The challenges associated with current NTFs delivery systems and how these systems can be applied to neurological diseases and disorders have been discussed in the review.In conclusion,optimal delivery systems for NTFs will be needed for reliable and meaningful clinical benefits;ideally,delivering a time and dose-controlled release of bioactive multiNTFs at different individual optimal kinetics to achieve multi-functions in target tissues is significant preferred. 展开更多
关键词 Neurotrophic factors Neurological disorders Drug delivery Sustained delivery release kinetics
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Phosphorus-enriched biochar from biogas residue of Eichhornia crassipes:transformation and release of phosphorus 被引量:1
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作者 Fan Yu Junxia Wang +7 位作者 Xutong Wang Yuting Wang Qianqian Guo Zhi Wang Xiaoqiang Cui Yanjun Hu Beibei Yan Guanyi Chen 《Biochar》 SCIE CAS CSCD 2023年第1期1405-1418,共14页
Pyrolysis is an effective technology for treating and utilizing biogas residue.To explore the phosphorus(P)supply capacity of the biochar generated from biogas residue of Eichhornia Crassipes,the P speciation of E.cra... Pyrolysis is an effective technology for treating and utilizing biogas residue.To explore the phosphorus(P)supply capacity of the biochar generated from biogas residue of Eichhornia Crassipes,the P speciation of E.crassipes biogas residue and biomass during pyrolysis(300-700℃)was analyzed by combining sequential chemical extraction,31P nuclear magnetic resonance(NMR)and P K-edge X-ray absorption near edge structure(XANES)spectroscopy.Pyrolysis treatment promoted the conversion of amorphous Ca-P phases in biogas residue and biomass into crystalline hydroxyapatite(HAP)phase,which matched the formation of stable HCl-P pools in the biochar derived from biogas residue(AEBs,22.65-82.04%)and biomass(EBs,13.08-33.52%)in the process of pyrolysis.Moreover,the total P contents in AEBs(19.43-28.92 mg g^(−1))were higher than that of EBs(3.41-5.26 mg g^(−1)),indicating that AEBs had a great P reclamation potential.The P release kinetics from AEBs and EBs in water were evaluated via an incubation experiment for 360 h.The P release from both AEBs and EBs conformed to the pseudo-second order kinetics model(R^(2)>0.93),but their P release behaviors were different.The P release of AEBs conformed to the diffusion-re-adsorption model,while that of EBs accorded with the diffusion-dissolution model.The diffusive gradients in thin-films(DGT)analysis showed that AEBs could significantly increase soil available P content as compared with EBs.Hence,the biochar produced from biogas residue of E.crassipes via pyrolysis has a good application potential as a P fertilizer. 展开更多
关键词 PYROLYSIS Phosphorus speciation BIOCHAR release kinetics AVAILABILITY
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Co-incorporation of hydrotalcite and starch into biochar-based fertilizers for the synthesis of slow-release fertilizers with improved water retention 被引量:1
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作者 Jiawei Lu Yongfu Li +2 位作者 Yanjiang Cai Peikun Jiang Bing Yu 《Biochar》 SCIE CAS CSCD 2023年第1期765-777,共13页
The unsatisfactory nutrient slow-release and water-retention performance of traditional biochar-based compound fertilizers(BCF)severely limit their practical application.Herein,a new type of slow-release fertilizer wi... The unsatisfactory nutrient slow-release and water-retention performance of traditional biochar-based compound fertilizers(BCF)severely limit their practical application.Herein,a new type of slow-release fertilizer with high water retention was fabricated via the incorporation of hydrotalcite and starch into BCF,named as HS-BCF.The waterretention and nutrient releasing performance of the prepared HS-BCF and related nutrient slow-release mechanism were investigated.The results showed that the incorporation of hydrotalcite and starch into BCF could increase the soil water-retention ratio by 5-10%points.The accumulated N,P,and K leaching amounts of HS-BCF in soil within 30 days were 49.4%,13.3%,and 87.4%of BCF at most,respectively.Kinetic analysis indicated that the release of nutrients from HS-BCF was attributed to the coupling of the diffusion-controlled and relaxation-controlled mechanism.Moreover,hydrotalcite could bind with P in HS-BCF,contributing to the enhanced durability of P in HS-BCF.Finally,pot experiments showed that the N-P-K utilization efficiencies of HS-BCF were all higher than those of BCF due to a better synchronization between the nutrient release of HS-BCF and the uptake of tomato plants.Overall,the study may provide a promising strategy for simultaneously improving the water-retention and slow-release performance of traditional biochar-based fertilizers. 展开更多
关键词 STARCH HYDROTALCITE Slow-release fertilizer release kinetics Water retention
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<i>In-Silico</i>Validation and Development of Chlorogenic Acid (CGA) Loaded Polymeric Nanoparticle for Targeting Neurodegenerative Disorders
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作者 Vinayak Agarwal Shriya Agarwal +4 位作者 Ramneek Kaur Pranav Pancham Harleen Kaur Siddhi Bhardwaj Manisha Singh 《Journal of Biomaterials and Nanobiotechnology》 2020年第4期279-303,共25页
<strong>Background: </strong>Recent decades witnessed a significant growth in terms of phytocompounds based therapeutics, extensively explored for almost all types of existing disorders. They have also bee... <strong>Background: </strong>Recent decades witnessed a significant growth in terms of phytocompounds based therapeutics, extensively explored for almost all types of existing disorders. They have also been widely investigated in Neurodegenerative disorders (NDDs) and Chlorogenic acid (CGA), a polyphenolic compound having potential anti-inflammatory and anti-oxidative properties, emerged as a promising compound in ameliorating NDDs. Owing to its poor stability, bioavailability and release kinetics, CGA needed a suitable nanocarrier based pharmaceutical design for targeting NDDs. <strong>Objective: </strong>The current study is aimed at the <em>in-silico</em> validation of CGA as an effective therapeutic agent targeting various NDDs followed by the fabrication of polymeric nanoparticles-based carrier system to overcome its pharmacological limitations and improve its stability. <strong>Methods:</strong> A successful <em>in-silico</em> validation using molecular docking techniques along with synthesis of CGA loaded polymeric nanoparticles (CGA-NPs) by ionic gelation method was performed. The statistical optimisation of the developed CGA-NPs was done by Box Behnken method and then the optimized formulation of CGA-NPs was characterised using particle size analysis (PSA), Transmission electron microscopy (TEM), Fourier Transform Infrared spectroscopy (FTIR) along with in-vitro release kinetics analysis.<strong> Results & Conclusion:</strong> The results attained exhibited average particle size of 101.9 ± 1.5 nm, Polydispersibility (PDI) score of 0.065 and a ZP of <span style="white-space:nowrap;">&#8722;</span>17.4 mV. On a similar note, TEM results showed a size range of CGA-NPs between 90 - 110 nm with a spherical shape of NPs. Also, the data from in-vitro release kinetics showed a sustained release of CGA from the NPs following the first-order kinetics suggesting the appropriate designing of nanoformulation. 展开更多
关键词 ANTIOXIDANT ANTI-INFLAMMATORY Polymeric Nanoparticles release kinetics Box Behnken Design Molecular Docking Particle Size Analysis
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Synthesis and Characterization of <i>Citrus limonum</i>Essential Oil Based Nanoemulsion and Its Enhanced Antioxidant Activity with Stability for Transdermal Application
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作者 Harleen Kaur Pranav Pancham +2 位作者 Ramneek Kaur Shriya Agarwal Manisha Singh 《Journal of Biomaterials and Nanobiotechnology》 2020年第4期215-236,共22页
Lemon oil (LO), also known as <em>Citrus limonum</em> is a highly volatile essential oil (EO) with potential therapeutic properties like anti-oxidative, anti-proliferative, anti-fungal and anti-cancerous. ... Lemon oil (LO), also known as <em>Citrus limonum</em> is a highly volatile essential oil (EO) with potential therapeutic properties like anti-oxidative, anti-proliferative, anti-fungal and anti-cancerous. However, the efficacy of LO is limited due to its physiological factors such as high volatility, poor stability (particularly sensitive to sunlight) and quick degradability upon exposure. To overcome these challenges, we formulated lemon oil loaded nanoemulsion system (LO-NE) (oil-in-water), using aqueous titration method. The formulation comprised of lemon oil (LO), Tween 80 and ethanol as oil, surfactant and co-surfactant phases respectively. The existence zone of NE was established by constructing pseudo-ternary phase diagrams using different concentrations of LO, surfactant and co-surfactant (S<sub>mix</sub>). The quantitative estimation of LO was performed using a high throughput gas chromatography, revealing the presence of various compounds like Limonene, Alpha-Pinene and Linalyl acetate followed by the estimation of total phenolics and flavonoid content. The characterization of LO-NE indicated the particle size of 60 ± 2.5 nm along with the polydispersity index of 0.125 and zeta potential of <span style="white-space:nowrap;">&#8722;</span>14.9 mV. The size range of the NE particles dispersed in the colloidal system was further verified by TEM micrograph which shows size range between 46.2 - 104.7 nm. All the anti-oxidant assays outcomes exhibited the higher activity of LO-NE in comparison to LO alone with lower IC<sub>50</sub> values. The release kinetics statistical data showed that LO-NE had a sustained release and followed the Higuchi’s model in comparison to burst release of LO alone. Lastly, the stability analysis of the optimised formulation (LO-NE) and LO was estimated through antioxidant assay and subjecting them for thermodynamic stability after 6 months. The results attained, showed higher stability and anti-oxidant capability of LO-NE than LO alone. The study suggested that formulated nanoemulsion can be effectively used as a highly efficacious biologically active alternative nanoformulation against many transdermal disorders. 展开更多
关键词 Lemon Oil SURFACTANTS Particle Size Analysis Ternary Phase Diagrams release kinetics Thermodynamic Stability
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Threshold Photoelectron-photoion Coincidence Imaging of Dissociation Dynamic of NO+ at c3∏(v′=0) State 被引量:1
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作者 孙金大 单晓斌 +6 位作者 刘付轶 盛六四 唐小锋 牛铭理 宋磊 周晓国 刘世林 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第5期509-512,621,共5页
The photodissociation of NO+ at c3∏(v′=0) state is studied by threshold photoelectron- photoion coincidence imaging method. By some assumptions, the relations between velocity in center of mass (CM) coordinates... The photodissociation of NO+ at c3∏(v′=0) state is studied by threshold photoelectron- photoion coincidence imaging method. By some assumptions, the relations between velocity in center of mass (CM) coordinates and most probable center of mass (MPCM) coordinates, time of flight and displacement in the velocity map image of fragment ions are derived using vector addition of velocity and displacement on the condition of perpendicular molecular beam. Using these relations the velocity in CM coordinates, the velocity and angular distri- bution of N+ fragment ions in MPCM coordinates are obtained and discussed, respectively. 展开更多
关键词 Threshold photoelectron-photoion coincidence imaging Velocity map imag-ing Nitric oxide kinetic energy released distribution Angular distribution
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Multi-reference configuration-interaction calculations on multiply charged ions of carbon monosulfide
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作者 闫冰 张玉娟 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期159-165,共7页
The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell elec... The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell electrons with the scalar relativistic effects are included in the present computations.The spectroscopic constants,dissociation energies,ionization energies for ground and low-lying excited states together with corresponding electronic configurations of ions are obtained,and a good agreement between the present work and existing experiments is found.No theoretical evidence is found for the adiabatically stable CSq+(q〉2) ions according to the present ab initio calculations.The calculated values for 1st-6th ionization energies are 11.25,32.66,64.82,106.25,159.75,and 224.64 eV,respectively.The kinetic energy release data of fragments are provided by the present work for further experimental comparisons. 展开更多
关键词 potential energy curve spectroscopic constants multi-reference configuration interaction kinetic energy release
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