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مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
اسکوپوس
مرکز اطلاعات علمی SID
ریسرچگیت
strs
نویسندگان: 

DEHGHANI F. | FOSTER N.R.

اطلاعات دوره: 
  • سال: 

    2003
  • دوره: 

    7
  • شماره: 

    -
  • صفحات: 

    363-369
تعامل: 
  • استنادات: 

    315
  • بازدید: 

    6451
  • دانلود: 

    9195
کلیدواژه: 
چکیده: 

آمار یکساله:  

بازدید 6451

دانلود 9195 استناد 315 مرجع 0
اطلاعات دوره: 
  • سال: 

    2009
  • دوره: 

    17
  • شماره: 

    1
  • صفحات: 

    6-12
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    36212
  • دانلود: 

    9525
چکیده: 

Background: The ability of supercritical fluids (SCFs), such as carbon dioxide, to dissolve and expand or extract organic solvents and as result lower their solvation power, makes it possible the use of SCFs for the precipitation of solids from organic solutions. The process could be the injection of a solution of the substrate in an organic solvent into a vessel which is swept by a supercritical fluid. The aim of this study was to ascertain the feasibility of supercritical processing to prepare different particulate forms of fluticasone propionate (FP), and to evaluate the influence of different liquid solvents and precipitation temperatures on the morphology, size and crystal habit of particles. Method: The solution of FP in organic solvents, was precipitated by supercritical carbon dioxide (SCCO2) at two pressure and temperature levels. Effects of process parameters on the physicochemical characteristics of harvested microparticles were evaluated.Results: Particle formation was observed only at the lower selected pressure, whilst at the higher pressure, no precipitation of particles was occurred due to dissolution of FP in supercritical antisolvent. The micrographs of the produced particles showed different morphologies for FP obtained from different conditions. The results of thermal analysis of the resulted particles showed that changes in the processing conditions didn’t influence thermal behavior of the precipitated particles.Evaluation of the effect of temperature on the size distribution of particles showed that increase in the temperature from 400C to 500C, resulted in reduction of the mean particle size from about 30 μm to about 120m.Conclusion: From the results of this study it may be concluded that, processing of FP by supercritical antisolvent could be an approach for production of diverse forms of the drug and drastic changes in the physical characteristics of microparticles could be achieved by changing the type of solvent and temperature of operation.

آمار یکساله:  

بازدید 36212

دانلود 9525 استناد 0 مرجع 0
نویسندگان: 

POURETEDAL HAMID REZA

اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    4
  • شماره: 

    1
  • صفحات: 

    1-9
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    21509
  • دانلود: 

    30233
چکیده: 

Nanoparticles of azithromycin are prepared using solvent/antisolvent precipitation method. The solubility of drug in water and the oral bioavailability are increased with decreasing particle size. The effect of type and concentration of surfactant and feed drug concentration are evaluated on the precipitated particle size. The nanoazithromycin in range 200–400 nm is obtained by the addition of absolute ethanol as solvent, water as antisolvent in presence of TweenÒ 80 as surfactant. The prepared nanoparticles are characterized by infra-red spectra, particle size distribution, scanning electron microscopy, X-ray diffraction and differential scanning calorimetry. The chemical structure of nanosized azithromycin does not show any change but the crystallinity reduces in comparison with raw drug. Dissolution of azithromycin nanoparticles in purified water and buffer phosphate (pH of 6.0) is 2.93 and 3.36, respectively, times of raw drug in 30 min.

آمار یکساله:  

بازدید 21509

دانلود 30233 استناد 0 مرجع 2220
گارگاه ها آموزشی
اطلاعات دوره: 
  • سال: 

    2020
  • دوره: 

    54
  • شماره: 

    2
  • صفحات: 

    297-309
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    7640
  • دانلود: 

    6218
چکیده: 

Experimental study of the effect of gas antisolvent (GAS) system conditions on the particle size distribution of finasteride (FNS) requires a thermodynamic model for the volume expansion process. In this study, the phase behavior of the binary system including carbon dioxide and Dimethyl sulfoxide, and a ternary system comprising carbon dioxide, dimethyl sulfoxide, and Finasteride was studied. The Peng-Robinson equation of state was employed for the evaluation of the fluid phases and a fugacity expression to represent the solid phase. By developing an accurate predictive model, the GAS operating conditions can be optimized to produce particles with no need for a large number of experiments. First, the critical properties of the FNS were evaluated by the group contribution methods. The method of Marrero and Gani was also selected to predict the normal boiling point, critical temperature, and critical pressure. The correlation of Edmister was chosen for the prediction of the acentric factor. The lowest pressures for the ternary system at 308, 318, 328, and 338 K were 7. 49, 8. 13, 8. 51, and 9. 03 MPa, respectively. The precipitation of the dissolved finasteride happened at these operating pressures.

آمار یکساله:  

بازدید 7640

دانلود 6218 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    1400
  • دوره: 

    18
  • شماره: 

    111
  • صفحات: 

    79-88
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    465
  • دانلود: 

    152
چکیده: 

روش ته نشینی ضد حلال، یکی از روش های مطلوب تولید نانوذرات کلوئیدی از ترکیبات غذایی است. هدف از این مطالعه، تولید نانوذرات جامد کلوئیدی بر پایه موم زنبور عسل و موم استخراجی از بره موم به روش ته نشینی ضد حلال است. به این منظور، اثر عوامل مختلف شامل نوع حلال (اتانول مطلق و ایزوپروپانول)، نوع امولسیفایر (پلی سوربات 80، کازئینات سدیم و مخلوط 1 به 1 آنها) و نوع ماده لیپیدی (موم و موم استخراجی از بره موم) بر پارامترهای اندازه ذرات، شاخص پراکندگی ذرات و راندمان تولید آنها به روش ته نشینی ضد حلال مورد بررسی قرار گرفت. بر اساس نتایج حاصل، کمترین اندازه ذرات متعلق به حلال اتانول مطلق (205 نانومتر) و امولسیفایر کازئینات سدیم (192 نانومتر) می باشد. نوع امولسیفایر به صورت خطی و نوع امولسیفایر/ نوع حلال به صورت اثر متقابل بر شاخص پراکندگی ذرات اثر معنی داری (05/0 p<) داشتند. شاخص پراکندگی ذرات تهیه شده در هر دو نوع موم کمتر از 21/0 و در حد مطلوب بود. نتایج حاصل از راندمان تولید ذرات نشان دادند که استفاده از مخلوط امولسیفایرها، حلال اتانول و موم بیشترین راندمان تولید (به ترتیب 92، 93 و 90 درصد) را دارا هستند. مطابق نتایج حاصل از اثر متقابل عوامل بر راندمان تولید، مخلوط امولسیفایرها فارغ از نوع حلال و نوع موم مورد استفاده، بالاترین راندمان را نشان داد. هم چنین، نانو ذرات موم تهیه شده با استفاده از حلال اتانول (حدود 5/91 درصد)، بیشترین راندمان تولید را نسبت به ذرات تولید شده از هر دو نوع موم با حلال ایزوپروپانول دارند. نتایج حاصل از این تحقیق نشان داد که روش ته نشینی ضد حلال می تواند به عنوان یک روش کارآمد برای تولید نانوذرات جامد لیپیدی مورد استفاده قرار گیرد. هم چنین مشخص گردید که موم و موم استخراجی از بره موم از پتانسیل خوبی برای تهیه نانوذرات لیپیدی برخوردار هستند.

آمار یکساله:  

بازدید 465

دانلود 152 استناد 0 مرجع 0
نویسندگان: 

MAGHSOODI MARYAM | ESMAEILZADEH SARA

اطلاعات دوره: 
  • سال: 

    2011
  • دوره: 

    7
  • شماره: 

    4
  • صفحات: 

    221-229
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    24289
  • دانلود: 

    8898
چکیده: 

In this study, the effect of recrystallization of naproxen in the presence of hydroxypropyl cellulose (HPC) on the release rate of drug was investigated. Crystals were generated by the anti-solvent approach using the HPC solution in water as the anti-solvent. The samples were subjected to various physicochemical evaluations such as crystal size, scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, solubility, wettability and dissolution studies. Results revealed that HPC play a key role in controlling the primary crystal size, morphology, size and surface properties of naproxen agglomerates. Crystallization of naproxen in the presence of HPC caused a marked modification of its dissolution. The particles obtained in the presence of HPC exhibited slower dissolution rate compared to those produced in the absence of HPC. This was attributed to the adsorption of HPC on the surface of the naproxen crystals. It was shown that the solubility of naproxen increased in solution containing HPC. Moreover, there was a significant difference between the solubility of untreated naproxen and that of samples crystallized in the presence of HPC in water. Contact angle measurements revealed that control crystals obtained in the absence of HPC have a greater contact angle than those produced in the presence of HPC. FT-IR spectroscopy results indicated the absence of any interaction between drug and HPC. This study highlights the influence of polymeric additive on the crystallization process leading to modified performance.

آمار یکساله:  

بازدید 24289

دانلود 8898 استناد 0 مرجع 0
strs
نویسندگان: 

TABBAKHIAN M. | HASANZADEH F. | TAVAKOLI N. | JAMSHIDIAN Z.

اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    9
  • شماره: 

    5
  • صفحات: 

    337-350
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    23755
  • دانلود: 

    12582
چکیده: 

Glibenclamide (GLIB) is a poorly soluble drug with formulation-dependent bioavailability. Therefore, we attempted in this study to improve GLIB dissolution rate by preparing drug solid dispersions by solvent evaporation (SE) and supercritical fluid solvent-antisolvent techniques (SCF-SAS). A D-optimal mixture design was used to investigate the effects of different ratios of HPMCE5 (50-100%), PEG6000 (0-40%), and Poloxamer407 (0-20%) on drug dissolution from different solid dispersion (SD) formulations prepared by SE. The ratios of carriers used in SCF-SAS method were HPMCE5 (fixed at 60%), PEG6000 (20-40%), and Poloxamer407 (0-20%). A constant drug: carrier weight ratio of 1:10 was used in all experiments. The SDs obtained were physically characterized and subjected to the dissolution study. The major GLIB bands in FTIR spectra were indicative of drug integrity. The reduced intensity and the fewer number of peaks observed in X-ray diffractograms (XRD) of GLIB formulations was the indicative of at least partial transformation of crystalline to amorphous GLIB. This change and/or dilution of drug in much higher amounts of carriers present caused disappearance of distinctive endothermic peaks in differential scanning calorimetry thermograms of GLIB formulations. The model generated according to the results of the D-optimal mixture design indicated that GLIB formulations comprising HPMC (50%-60%), PEG (34-40%), and poloxamer (6-10%) had enhanced dissolution performances. As compared to SE method, the SCF-SAS technique produced formulations of higher dissolution performances, likely due to the effects of solution and the supercritical CO2 (SC-CO2) on enhanced plasticization of polymers and thus increased diffusion of the drug into the polymer matrix.

آمار یکساله:  

بازدید 23755

دانلود 12582 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    2006
  • دوره: 

    3
  • شماره: 

    4
  • صفحات: 

    17-22
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    15350
  • دانلود: 

    7767
چکیده: 

In this work the volume expansion for the binary systems of ethanol and toluene, as industrial organic solvents, in the presence of nearcritical and supercritical carbon dioxide, CO2, at a temperature range of 293 to 333 K has been meticulously measured. The effect of the temperature and pressure of binary systems on volume expansion for organic solvents have also been investigated. It can be observed that by increasing the pressure of the system at a constant temperature, the volume of the liquid phase increases smoothly, while at higher pressures a sudden volume expansion can occur. The range of pressure that can lead to a sudden increase in the volume expansion of the liquid phase in each specified temperature can be reported as a proper condition in producing micro and nanoparticles. The experimental data for the volume expansion of organic solvents were modeled using the conventional cubic Peng Robinson equation of state. The Average Absolute Relative Deviation percent (AARD%) for the binary systems of ethanol + CO2 and toluene + CO2 were reported as 14.9% and 15.1%. As inferred, it is vital to develop a thermodynamic model with greater accuracy in order to correlate the volume expansion of the systems studied in this work at various conditions.

آمار یکساله:  

بازدید 15350

دانلود 7767 استناد 0 مرجع 0
نویسندگان: 

HOWARD K.S. | NAGY Z.K. | SAHA B.

نشریه: 

CRYSTAL GROWTH AND DESIGN

اطلاعات دوره: 
  • سال: 

    2009
  • دوره: 

    9
  • شماره: 

    -
  • صفحات: 

    3964-3975
تعامل: 
  • استنادات: 

    315
  • بازدید: 

    1972
  • دانلود: 

    9195
کلیدواژه: 
چکیده: 

آمار یکساله:  

بازدید 1972

دانلود 9195 استناد 315 مرجع 0
نشریه: 

PHARMACEUTICAL SCIENCES

اطلاعات دوره: 
  • سال: 

    2017
  • دوره: 

    23
  • شماره: 

    3
  • صفحات: 

    215-221
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    10755
  • دانلود: 

    6699
چکیده: 

Background: The antisolvent precipitation technique has evolved into an effective method to prepare microcrystals of drug. Although this method has advantages, such as cost effectiveness, the processing is significantly sensitive to stabilizer. The aim of present study was to prepare celecoxib (CLX) microcrystals via antisolvent precipitation technique without any surfactants. Methods: Acetone was used as a solvent for the CLX and water was used as an antisolvent. During the precipitation process, several experimental parameters, such as the volume ratio of antisolvent to CLX solution, the concentration of CLX solution, the temperature and the stirring speed, were investigated. Results: The results showed that external characteristics such as particle size and its distribution were strongly influenced by the process parameters, while the internal structures such as chemical composition and crystal structure were unaffected during the process. Higher volume ratio of antisolvent to CLX solution, lower temperature and more-intense stirring led to the smaller crystals. However, increasing the concentration of CLX solution resulted in aggregation of crystals and consequently formation of large crystals with more heterogeneous distribution. It was found that this effect could be prevented by using of ethanol as co-solvent with volume ratio to acetone 5: 1. Under the optimum conditions, the yielded powder had a mean particle size of 7 μ m and 70 % of the particles were distributed in the range of 0. 3-15 μ m. Conclusion: Results of this study offer a useful starting point for a conceptual framework to guide the preparation of microcrystals without using a stabilizer.

آمار یکساله:  

بازدید 10755

دانلود 6699 استناد 0 مرجع 0
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