Homogenization Speed Research Articles

Optimizing the Process Parameters for Encapsulation of Linamarin into PLGA Nanoparticles Using Double Emulsion Solvent Evaporation Technique

AbstractLinamarin‐loaded poly(lactide‐co‐glycolide) (PLGA) nanoparticles were prepared by using a double emulsion solvent evaporation method using polyvinyl alcohol as a surfactant. A two‐factor full factorial design, Box–Behnken design and surface response methodology, were employed to improve the nanoparticle yield, particle size, and drug encapsulation efficiency by determining the optimum levels of the process parameters, namely the polymer concentration, surfactant concentration, and homogenization speed. Both linear and quadratic empirical models were developed to express each response parameter as a function of the studied factors. A total of 12 and 17 experimental runs were necessary to obtain adequate empirical models (p < 0.05) for both factorial and Box–Behnken designs, respectively. The final optimum values for the polymer concentration, surfactant concentration, and homogenization speed were determined at 9.8 mg/mL, 50 mg/mL, and 23,000 rpm, respectively. Formulations obtained at this optimum preparing condition resulted on average 96% yield, 61.2% drug encapsulation efficiency, and 144.6 nm particle size. However, all prepared nanoparticles showed some kind of controlled drug release; most likely the final optimized nanoparticles exhibited the most biphasic controlled drug release profile with a minimal burst release and overall drug release of <30% in 120 h of incubation. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E486–E504, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21295

Long-acting formulation of a new muscarinic receptor antagonist for the treatment of overactive bladder

A new muscarinic receptor antagonist, 5-hydroxymethyl tolterodine (5-HMT), was successfully encapsulated into PLGA microspheres. With an increase of PLGA concentration from 15% to 40%, encapsulation efficiency of 5-HMT increased from 55.39% to 76.32%, and the particle size of microsphere increased from 34.33 to 70.48 µm. Increasing the homogenisation speed from 850 to 2300 rpm, the particle size was reduced about 65%.The in vitro and in vivo studies in beagle dogs show that the release profile of 5-HMT-loaded microspheres (5-HMT MS) prepared with 503H is characterised by a low initial burst followed by slow release that lasted for 2 weeks. A Cmax of 1.617 ± 0.392 ng/mL was found on the sixth day. When evaluated for inhibition of the carbachol-induced contraction of rat urinary bladder, 5-HMT MS showed a much longer and more potent effect than tolterodine tablets. The mean urination time of the rats in the 5-HMT MS group was significantly decreased (p < 0.05 or p < 0.01) to less than 2 weeks.

Preparation and optimization of matrix metalloproteinase-1-loaded poly(lactide-co-glycolide-co-caprolactone) nanoparticles with rotatable central composite design and response surface methodology

Matrix metalloproteases are key regulatory molecules in the breakdown of extracellular matrix and in inflammatory processes. Matrix metalloproteinase-1 (MMP-1) can significantly enhance muscle regeneration by promoting the formation of myofibers and degenerating the fibrous tissue. Herein, we prepared novel MMP-1-loaded poly(lactide-co-glycolide-co-caprolactone) (PLGA-PCL) nanoparticles (NPs) capable of sustained release of MMP-1. We established quadratic equations as mathematical models and employed rotatable central composite design and response surface methodology to optimize the preparation procedure of the NPs. Then, characterization of the optimized NPs with respect to particle size distribution, particle morphology, drug encapsulation efficiency, MMP-1 activity assay and in vitro release of MMP-1 from NPs was carried out. The results of mathematical modeling show that the optimal conditions for the preparation of MMP-1-loaded NPs were as follows: 7 min for the duration time of homogenization, 4.5 krpm for the agitation speed of homogenization and 0.4 for the volume ratio of organic solvent phase to external aqueous phase. The entrapment efficiency and the average particle size of the NPs were 38.75 ± 4.74% and 322.7 ± 18.1 nm, respectively. Further scanning electron microscopy image shows that the NPs have a smooth and spherical surface, with mean particle size around 300 nm. The MMP-1 activity assay and in vitro drug release profile of NPs indicated that the bioactivity of the enzyme can be reserved where the encapsulation allows prolonged release of MMP-1 over 60 days. Taken together, we reported here novel PLGA-PCL NPs for sustained release of MMP-1, which may provide an ideal MMP-1 delivery approach for tissue reconstruction therapy.

Effect of Extraction Methods on the Types and Levels of Free Amino Acid of Beef Longissimus Muscle

The current study was carried out to investigate the impact of extraction conditions on the free amino acid level and type in beef longissimus muscle. The sample blocks were chiller aged for 1 d and 7 d at <TEX>$4^{\circ}C$</TEX>. There are three homogenization speeds (11,000, 19,000 and 24,000 rpm) for bigger and two speeds (11,000 and 13,000 rpm) for smaller homogenizer's dispersing tools were used for evaluation. Results showed that chiller ageing greatly (p<0.05) increased extractable free amino acids, except cystine. Homogenization with the bigger dispersing tool at 24,000 rpm resulted in the highest free amino acid levels for both 1 and 7 d samples. Significant differences (p<0.05) in the mean values of most amino acids due to the effect of speed and interactions between ageing times. However, the speed effect and interaction between ageing with homogenization speed were not significant (p>0.05) for most of the amino acids except valine and isoleucine when using the smaller dispensing tools. The current data indicated that a standardized method for free amino acid types and levels of aged beef samples. In addition, the results also suggested that utilization of a big dispensing tool at high homogenization speed is a better condition for releasing free amino acid contents in beef samples.

DEVELOPMENT OF MICROSPHERES COVERED WITH HYDROXYAPATITE NANOCRYSTALS AS CELL SCAFFOLD FOR ANGIOGENESIS

We prepared poly(L-lactide-co-glycolide) cell scaffolds coated with hydroxyapatite (HAp) nanocrystals with 50–100 nm in diameter via the Pickering emulsion method. Our cell scaffolds were composed of biodegradable polymers and HAp nanocrystals as a core and shell, respectively. The scaffolds were spherical but displayed uneven shapes when altering a shear speed of homogenization during syntheses. The surface coverage of HAp nanocrystals was examined because the HAp-coating ratio for the scaffolds was an important factor as cell scaffolds in order to enhance cell adhesion. On the basis of scanning electron microscopy observations and thermogravimetric analyses, it was found that the cell scaffolds showed distorted morphologies, and the HAp-coating ratio decreased with increasing the shear speed in the synthesis because shear stress influenced shapes of the scaffolds.

Biodegradable Nanoparticles for Protein Delivery: Analysis of Preparation Conditions on Particle Morphology and Protein Loading, Activity and Sustained Release Properties

PLGA particles have been extensively used as a sustained drug-delivery system, but there are multiple drawbacks when delivering proteins. The focus of this work is to address the most significant disadvantages to the W/O/W double emulsion procedure and demonstrate that simple changes to this procedure can have significant changes to particle size and dispersity and considerable improvements to protein loading, activity and sustained active protein release. A systematic approach was taken to analyze the effects of the following variables: solvent miscibility (dichloromethane (DCM), ethyl acetate, acetone), homogenization speed (10 000–25 000 rpm), PLGA concentration (10–30 mg/ml) and additives in both the organic (sucrose acetate isobutyrate (SAIB)) and aqueous (bovine serum albumin (BSA)) phases. Increasing solvent miscibility decreased particle size, dispersity and protein denaturation, while maintaining adequate protein loading. Increasing solvent miscibility also lowered the impact of homogenization on particle size and dispersity and protein activity. Changes to PLGA concentration demonstrated a minimum impact on particle size and dispersity, but showed an inverse relationship between protein encapsulation efficiency and particle protein weight percent. Most particles tested provided sustained release of active protein over 60 days. Increasing solvent miscibility resulted in increases in the percent of active protein released. When subjected to synthesis conditions with DCM as the solvent, BSA as a stabilizer resulted in the maximum stabilization of protein at a concentration of 100 mg/ml. At this concentration, BSA allowed for increases in the total amount of active protein delivered for all three solvents. The benefit of SAIB was primarily increased protein loading.

코팅물질과 유화제가 나노입자 제조 및 안정성에 미치는 영향

본 실험은 emulsion-diffusion 방법을 이용한 코팅물질과 유화제를 혼합하여 균질하여 유화액을 만든 후 증류수를 첨가하여 확산시킴으로써 나노입자를 제조하는 방법을 사용하였다. 유화공정에 따른 변화를 살펴보기 위하여 균질기 종류와 균질 속도, 균질 시간을 달리하여 그에 따른 입자크기의 변화를 살펴보고, 나노유화액이 가장 잘 제조되는 조건에서 여러 종류의 코팅물질과 유화제를 이용하여 나노입자의 크기 변화를 살펴보았다. 또한 저장 온도와 저장 기간에 따른 나노입자 크기를 관찰 하고 그에 따른 활성에너지를 산출하였다. 유화 공정에 따른 나노입자 크기의 변화를 살펴보면 NEO II의 경우가 가장 작고 고른 나노입자을 형성하였다. 또한 균질 속도가 증가할 수록 입자가 작아지는 것을 알 수 있었다. 하지만 균질 시간이 증가될수록 입자크기가 증가되는 경향을 보였다. PF68은 유화 능력이 가장 좋은 유화제로 관찰되었고 코팅물질은 PCL이 가장 우수한 능력을 나타내어 나노입자를 제조하는데 있어서 가장 적당하다고 사료되었다. 저장 기간에 따른 입자크기를 살펴보면 저장 기간이 증가할수록 크기가 증가하며, 저장 온도가 낮을수록 변화의 폭이 더 큰 것을 알 수 있었다. 본 연구를 통해 균질기 종류, 균질시간, 균질 속도, 코팅물질 그리고 유화제등은 유화액을 제조할 때 중요한 공정 조건이며 다양한 나노캡슐화 공정으로 원하는 크기의 나노입자를 제조할 수 있다고 사료된다. The objective of this study was to investigate the influence of emulsion processing with various homogenization treatments on the physical properties of nanoparticles. For the manufacturing of nanoparticles, by taking the emulsion-diffusion method, various coating materials, such as gum arabic, hydroxyethyl starch, polycarprolactone, paraffin wax, <TEX>${\kappa}$</TEX>-carrageenan and emulsifiers like Tween<TEX>$^{(R)}$</TEX>60, Tween<TEX>$^{(R)}$</TEX>80, monoglyceride and Pluronic<TEX>$^{(R)}$</TEX>F68, were added into the emulsion system. Furthermore, the various speeds (7,000 rpm to 10,000 rpm), and times (15 s to 60 s) of homogenization were treated during the emulsion- diffusion process. NEO II homomixer was the most effective homogenizer for making nanoparticles as 51 nm (<TEX>$D_{10}$</TEX>) and 26 nm (<TEX>$D_{50}$</TEX>). To manufacture smaller nanoparticles, by using NEO II homomixer, 10,000 rpm of agitation speed, polycaprolactone as coating material, and Pluronic<TEX>$^{(R)}$</TEX>F68 as an emulsifier were the optimum operating conditions and components. For the stability of nanoparticles for 7 days, <TEX>$20^{\circ}C$</TEX> of storage temperature was appropriate to maintain the particle size. From these results, the type of homogenizer, homogenization speed, homogenization time and storage temperature could affect the particle size. Moreover, type of coating materials and emulsifier also influenced the size and stability of the nanoparticles.

Enhanced transdermal delivery and optimization of nano-liposome preparation using hydrophilic drug

The aim of this study is the appropriate manufacture of nano-liposome and evaluation of transdermal drug delivery after drug was loaded in liposome for topical site especially nose. To make small, stable, uniform and highly encapsulated nano-liposome, many factors including solvent, stabilizer, pH balance, homogenization speed, sonication time and filtration are critical. Especially, stearate series surfactants have positive effects on liposome size and long-term stability. In this experiment, unsaturated lecithin and Pseudoephedrine HCl (PSE) were selected for the surfactant and model drug, respectively. The unsaturated lecithin, one of the surfactants used to make the liposome, has excellent skin affinity and penetration. Tween 20 and Tween 80, support emulsifying agents, propylene glycol, a lecithin solvent and triethanolamine as stabilizer were also used as materials for liposome. Nano-liposome was made with a high shear homogenizer and pulverized by ultrasonicator to reduce the size and increase uniformity. After that, a transdermal experiment was conducted with Franz-cells on hairless mouse skin and PSE was determined by HPLC. Based on the results of the experiments, when the appropriate concentrations of support emulsifying agent and stabilizer were added, the average size of the liposome was about 300 nm and the encapsulation rate was close up to 40%. Moreover, with faster mixing speed and longer sonication time, more uniform and smaller particles tended to be manufactured. In the skin permeation test, PSE entrapped in liposome had 20 times higher permeability than PSE raw material.

Effect of homogenization speed and time on the recovery of alkaline phosphatase from the hepatopancreatic tissues of shrimps

Hepatopancreatic tissues of shrimps were homogenized at various pestle speed and time intervals at a constant jerk of 15 passes/min on a narrow space using 0.1 M Tris-HCl buffer of pH 8.4 at 4°C. Release of proteins and alkaline phosphatase were determined by estimating the quantity of protein and alkaline phosphatase activity in each homogenate at the end of the experiments. Optimum condition for the homogenization of the hepatopancreatic cells was achieved at operating speeds of 3,000 rpm for 10 min in the homogenizer. Increase in pestle speed beyond 3,000 rpm for 10 min have no effect on the release of protein. Increasing the disruption speed above 3,000 rpm decreases the specific activity of alkaline phosphatase release, while extending the time of homogenization beyond 10 min at 3,000 rpm or the speed of pestle beyond 3,000 rpm for 10 min caused shear damage to the enzyme.

Evaluation and optimization of factors affecting novel diclofenac sodium- eudragit RS100 nanoparticles

The major concern of the present study was to evaluate the processing conditions and formulation factors affecting diclofenac sodium –eudragit RS100 nanoformulation size and their optimization to reach optimized nanoparticle (size below 200 nm). Diclofenac sodium –eudragit RS100 nanoparticles were formulated using nanoprecipitation – solvent deposition technique (the single emulsion technique). The effect of several process parameters, that is, homogenization type (homogenizer or sonicator), speed of homogenization, dispersing agent characteristics, the quantity and ratio of phases, drug-polymer content and ratio and also temperature of quasi-emulsion in the time of preparation were considered on the size of the nanoformulations. Particle size and size distribution of nanoparticles were studied by applying laser diffraction particle size analyzer, and morphology of the nanoparticles was also inspected by transmission electron microscopy (TEM). All the prepared formulations using eudragit RS100 resulted in nano-range size particles with relative spherical smooth morphology and drug loading efficiency of nearly 100%. According to these findings, nanoprecipitation – solvent deposition technique was able to engineer diclofenac sodium –eudragit RS100 nanoparticles to reach target size that could undergo more studies for evaluation and comparison of the anti-inflammatory effect of drug in nanoparticles with classical dosage forms following its ocular administration.

Emulsification of heavy crude oil in water by natural surfactants

The factors affecting the stability of a heavy crude oil-in-water emulsion stabilized by sodium carbonate (Na2CO3) as a natural surfactant were studied. An Iranian heavy crude oil, namely West Paydar, was used as the oil phase of the emulsions. Tap water was used as the aqueous phase. Various concentrations of sodium chloride were employed to study the effect of aqueous phase salinity on the stability and interfacial tension of the emulsions. The stability and viscosity of O/W emulsions and their viability for the transportation of heavy crude oil through the pipeline were investigated. The diverse factors affecting the properties of emulsions were investigated.The study reveals that the stability of the oil-in-water emulsions was increased versus surfactant concentration due a decrease in the crude oil–water interfacial tension. The natural surfactant was responsible for the very low values of interfacial tensions observed and for the stabilization of the viscous crude oil-in-water emulsions. By increasing the surfactant concentration in the aqueous phase, as well as the speed and duration of homogenization, the emulsion stability was increased. There was a limit of 60vol.% for the crude oil content in the emulsions, beyond that the emulsions were inverted into water-in-oil emulsions. Zeta potential measurements revealed that the zeta potential of emulsion droplets decreased by the concentration of sodium carbonate in the aqueous phase.

A bench-scale high-shear wet-milling test for wheat flour

Bench-scale wet-milling tests for wheat flour are available for the traditional processes of Martin and Batter, but tests for the high-shear processes of Alfa-Laval/Raisio, Hydrocyclone, and High-Pressure Disintegration are few in number. In this study, critical processing parameters of a high-shear wet-milling process, namely high-shear mixing, gluten-aging, and gluten-washing steps, were investigated using response surface methodology, and those parameters led to a bench-scale wet-milling test starting with a “highly sheared flour–water dispersion” (HS-FWD). Optimum conditions for the test were: a water–flour ratio (db) of 1.7, water temperature of 35°C, and homogenizer speed of 6000rpm for 2.0min in the high-shear mixing step, a temperature of 40°C for 20min in the gluten-aging step, and gluten-washing of 2.0min in the Glutomatic system. The HS-FWD wet-milling test with high level of repeatability was capable of discriminating wet-milling qualities of several hard, soft, and coarsely ground wheat flours.

Colloidal gold-loaded, biodegradable, polymer-based stavudine nanoparticle uptake by macrophages: an in vitro study.

We describe the development, evaluation, and comparison of colloidal gold-loaded, poly(d,l-lactic-co-glycolic acid)-based nanoparticles containing anti-acquired immunodeficiency syndrome drug stavudine and uptake of these nanoparticles by macrophages in vitro. WE USED THE FOLLOWING METHODS IN THIS STUDY: drug-excipient interaction by Fourier transform infrared spectroscopy, morphology of nanoparticles by field-emission scanning electron microscopy, particle size by a particle size analyzer, and zeta potential and polydispersity index by a zetasizer. Drug loading and in vitro release were evaluated for formulations. The best formulation was incorporated with fluorescein isothiocyanate. Macrophage uptake of fluorescein isothiocyanate nanoparticles was studied in vitro. Variations in process parameters, such as speed of homogenization and amount of excipients, affected drug loading and the polydispersity index. We found that the drug was released for a prolonged period (over 63 days) from the nanoparticles, and observed cellular uptake of stavudine nanoparticles by macrophages. Experimental nanoparticles represent an interesting carrier system for the transport of stavudine to macrophages, providing reduced required drug dose and improved drug delivery to macrophages over an extended period. The presence of colloidal gold in the particles decreased the drug content and resulted in comparatively faster drug release.

Critical Process Parameters Evaluation of Modified Nanoprecipitation Method on Lomustine Nanoparticles and Cytostatic Activity Study on L132 Human Cancer Cell Line

This work was focused on identification and evaluation of process parameters of modified nanoprecipitation method, for fabrication of lomustine nanoparticles, with the aim of reducing cancer cell viability at low concentration of lomustine. The parameters controlling particle size, mostly in nanosize, were solvent/nonsolvent composition and emulsification speed of homogenizer along with aqueous phase volume. This controlled particle size is below 250 nm. The stabilizer concentration controlled particle size is within 68 nm ± 0.89 to 137 ± 0.94 nm with PDI 0.06 ± 0.008 to 0.25 ± 0.001. But, the stabilizer addition mode showed more uniform size distribution with PDI 0.085 ± 0.004. Entrapment efficiency was maintained well above 47 ± 0.23%. The drug release pattern was monophasic with controlled release over 24 hrs. In the method used, drug content was affected by ratio of polymer to drug to organic solvent, as well as homogenization speed and time. Percentage viable cells of L132 human lung cancer cell line remained, were only 5% at 100 μg/ml lomustine equivalent PLA nanoparticles.

Endogenously Expressed Muscarinic Receptors in HEK293 Cells Augment Up-regulation of Stably Expressed α4β2 Nicotinic Receptors

Nicotine-induced up-regulation of neuronal nicotinic receptors (nAChRs) has been known and studied for more than 25 years. Other nAChR ligands can also up-regulate nAChRs, but it is not known if these ligands induce up-regulation by mechanisms similar to that of nicotine. In this study, we compared up-regulation by three different nicotinic agonists and a competitive antagonist of several different nAChR subtypes expressed in HEK293 cells. Nicotine markedly increased α4β2 nAChR binding site density and β2 subunit protein. Carbachol, a known nAChR and muscarinic receptor agonist, up-regulated both α4β2 nAChR binding sites and subunit protein 2-fold more than did nicotine. This increased up-regulation was shown pharmacologically to involve endogenously expressed muscarinic receptors, and stimulation of these muscarinic receptors also correlated with a 2-fold increase in α4 and β2 mRNA. Muscarinic receptor activation in these cells appears to affect CMV promoter activity only minimally (∼1.2 fold), suggesting that the increase in α4 and β2 nAChR mRNA may not be dependent on enhanced transcription. Instead, other mechanisms may contribute to the increase in mRNA and a consequent increase in receptor subunits and binding site density. These studies demonstrate the possibility of augmenting nAChR expression in a cell model through mechanisms and targets other than the nAChR receptor itself.

Recovery of synthetic dye from simulated wastewater using emulsion liquid membrane process containing tri-dodecyl amine as a mobile carrier

The extraction of Red 3BS reactive dye from aqueous solution was studied using emulsion liquid membrane (ELM). ELM is one of the processes that have very high potential in treating industrial wastewater consisting of dyes. In this research, Red 3BS reactive dye was extracted from simulated wastewater using tridodecylamine (TDA) as the carrier agent, salicyclic acid (SA) to protonate TDA, sodium chloride as the stripping agent, kerosene as the diluent and SPAN 80 as emulsifier. Experimental parameters investigated were salicyclic acid concentration, extraction time, SPAN 80 concentration, sodium chloride concentration, TDA concentration, agitation speed, homogenizer speed, emulsifying time and treat ratio. The results show almost 100% of Red 3BS was removed and stripped in the receiving phase at the optimum condition in this ELM system. High voltage coalesce was applied to break the emulsion hence, enables recovery of Red 3BS in the receiving phase.

Preparation and characterization of carbon black‐polystyrene composite particles by high‐speed homogenization assisted suspension polymerization

AbstractComposite particles of carbon black‐polystyrene with controllable size were successfully prepared using high‐speed homogenization‐assisted suspension polymerization. The carbon black particles were modified by oleic acid to make it more hydrophobic and more compatible with polymers before the encapsulation process. The effects of homogenization speed, homogenization time, agitation speed, pigment concentration, and stabilizer concentration on the properties of complex spheres were investigated in detail. The results of orthogonal experiments proved that the stabilizer concentration plays the most important role in controlling the size of complex particles. The particles were also characterized by FTIR and SEM. SEM photographs proved that the complex particles had good spherical forms with smooth surfaces. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A comparative study of experimental optimization and response surface optimization of Cr removal by emulsion ionic liquid membrane

A comparative study on the optimization of process parameters of an emulsion ionic liquid membrane (EILM) by experimental work and response surface methodology (RSM) has been carried out. EILM was prepared by using kerosene as solvent, Span 80 as surfactant, NaOH as internal reagent, a hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM] +[NTf 2] −) as a stabilizer and a second ionic liquid tri-n-octylmethylammonium chloride (TOMAC) as a carrier. The prepared EILM was used to separate and concentrate Cr from wastewaters. The comparison between the experimentally optimized and the RSM optimized values was accomplished by optimizing the following parameters: homogenization speed, carrier concentration, internal phase concentration, agitation speed, treat ratio, internal to membrane phase ratio, surfactant concentration and pH of the feed phase. The comparison showed that all the values were in good agreement except for the internal phase concentration and the treat ratio. It was observed that the stability provided by [BMIM] +[NTf 2] − decreased as the extraction progressed due to its high density. Nevertheless, a good stability could be obtained by the combination of [BMIM] +[NTf 2] − and Span 80 during extraction process.

Chromium removal by emulsion liquid membrane using [BMIM] +[NTf 2] − as stabilizer and TOMAC as extractant

A new type of emulsion liquid membrane (ELM) has been prepared to separate and concentrate chromium (Cr) from waste water. A hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM] +[NTf 2] −) is used in the membrane phase as a stabilizer to provide sufficient stability and a second ionic liquid Tri-n-octylmethylammonium chloride (TOMAC) as a carrier. The other components to prepare emulsion are kerosene as solvent, span 80 as surfactant and NaOH as an internal reagent. In the present experimental investigation, the effects of various parameters such as homogenization speed, carrier concentration, internal phase concentration, agitation speed, treat ratio, internal to membrane phase ratio, surfactant concentration, pH of the feed phase and ([BMIM] +[NTf 2] − concentration on the % removal of Cr have been reported. At an optimum condition, 97% percentage of Cr could be extracted. Results showed that the stabilizing effect of [BMIM] +[NTf 2] − keeps on decreasing as the extraction proceeds. However, the provided stability by the combination of [BMIM] +[NTf 2] − and span 80 has been found to be sufficient during the extraction process.

Application of Rotatable Central Composite Design in the Preparation and Optimization of Poly (Lactic-co-Glycolic Acid) Nanoparticles for Controlled Delivery of HSA

The purpose of this work was to obtain an optimized Human Serum Albumin (HSA)-loaded poly(lactic- co -glycolic acid) (PLGA) nanoparticles (NPs). A rotatable central composite design (RCCD) was applied to evaluate the joint influence of three formulation variables: the duration time of homogenization, agitation speed of homogenization, and volume ratio of organic solvent phase to external aqueous phase. The experimental datum allowed the development quadratic models ( P <0.05) describing the inter-relationship between the dependent and independent variables. To enhance the protein content and minimize the particle size of the NPs simultaneously, a response surface methodology was employed. By solving the regression equation, and analyzing the response surface contour and plots, the optimal conditions for the preparation of HSA-loaded NPs were found to be: the duration time of homogenization was 4 min, the agitation speed of homogenization was 3.5 krpm and the volume ratio of organic solvent phase to external aqueous phase was 0.6. The entrapment efficiency (E.E.) was 54.52 ± 5.86% and the average particle size is 252.7 ± 17.90 nm. The NPs, as examined by scanning electron microscopy (SEM), have a smooth and spherical surface and particle sizes are less than 500 nm. The results indicated that RCCD represents an ideal and potential technique for NPs preparation optimization.