Optimization of Extraction Process of Clerodendrum philippinum Schauer var. simplex Mlodenke Total Flavonoids(CPTF) by Central Composite Design-Response Surface Methodology

[Objectives] The research aimed to optimize extraction process of Clerodendrum philippinum Schauer var. simplex Mlodenke total flavonoids( CPTF),and provide reference for its development and utilization. [Methods] Based on single-factor test,ethanol concentration,extraction temperature and extraction time were taken as independent variables,and total flavonoids yield was taken as dependent variable. The test was conducted according to central composite design principle. Multivariate linear regression and binomial equation fitting of the result were conducted,and extraction process of CPTF was optimized by using response surface methodology. [Results]The optimal extraction process of CPTF was as below: ethanol concentration 54. 76%,extraction temperature 83. 92℃,extraction time 102. 64 min,solid-liquid ratio 1:20,extraction for twice. [Conclusions] The extraction process of CPTF by central composite design-response surface methodology was simple and feasible,with reliable prediction result,which was suitable for industrial production.

Optimization of Extraction Process of Total Flavonoids from Akebia trifoliata (Thunb.) Koidz. by Central Composite Design-Response Surface Methodology

[Objectives]To optimize extraction process of total flavonoids from Akebia trifoliata( Thunb.) Koidz.,so as to provide references for development and use of Akebia trifoliata( Thunb.) Koidz. [Methods]The extraction rate of total flavonoids of Akebia trifoliata( Thunb.)Koidz. was taken as observation indicator. On the basis of single factor experiment,central composite design( CCD) was used to evaluate the effects of the extraction temperature,extraction time,and ethanol concentration on the extraction process. Multiple linear regression and binomial fitting were used,and response surface methodology( RSM) was used to select the optimum extraction process. [Results] The optimum extraction process conditions for total flavonoids of Akebia trifoliata( Thunb.) Koidz. was extraction temperature: 83. 92 ℃; extraction time:96. 47 min; ethanol concentration: 63. 92%; extraction times: two times; solid to liquid ratio: 1 ∶ 20; extraction rate of total flavonoids:4. 55%. [Conclusions] The central composite design-response surface methodology( CCD-RSM) is simple,convenient,and feasible for extraction of total flavonoids from Akebia trifoliata( Thunb.) Koidz.,and the prediction results are reliable.

Optimization and Characterization of Cellulose Extraction from Grevillea robusta (Silky Oak) Leaves by Soda-Anthraquinone Pulping Using Response Surface Methodology

Response surface methodology (RSM) using the central composite design (CCD) was applied to examine the impact of soda-anthraquinone pulping conditions on Grevillea robusta fall leaves. The pulping factors studied were: NaOH charge 5% to 20% w/v, pulping time 30 to 180 minutes, and the anthraquinone charge 0.1 to 0.5% w/w based on the oven-dried leaves. The responses evaluated were the pulp yield, cellulose content, and the degree of delignification. Various regression models were used to evaluate the effects of varying the pulping conditions. The optimum conditions attained were;NaOH charge of 14.63%, 0.1% anthraquinone, and a pulping period of 154 minutes, corresponding to 20.68% pulp yield, 80.56% cellulose content, and 70.34% lignin removal. Analysis of variance (ANOVA), was used to determine the most important variables that improve the extraction process of cellulose. The experiment outcomes matched those predicted by the model (Predicted R2 = 0.9980, Adjusted R2 = 0.9994), demonstrating the adequacy of the model used. FTIR analysis confirmed the elimination of the non-cellulosic fiber constituents. The lignin and hemicellulose-related bands (around 1514 cm−1, 1604 cm−1, 1239 cm−1, and 1734 cm−1) decreased with chemical treatment, indicating effective cellulose extraction by the soda-anthraquinone method. Similar results were obtained by XRD, SEM and thermogravimetric analysis of the extracted cellulose. Therefore, Grevillea robusta fall leaves are suitable renewable, cost-effective, and environmentally friendly non-wood biomass for cellulose extraction.

Application of response surface methodology and central composite rotatable design for modeling the influence of some operating variables of the lab scale thickener performance

This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a lab scale thickener for dewatering of tailing in the flotation circuit.Four thickener operating variables,namely feed flowrate,solid percent,flocculant dosage and feedwell height were changed during the tests based on CCRD.The ranges of values of the thickener variables used in the design were a feed flowrate of 9–21 L/min,solid percent of 8%–20%,flocculant dosage of 1.25–4.25 g/t and feedwell height of 16–26 cm.A total of 30 thickening tests were conducted using lab scale thickener on flotation tailing obtained from the Sarcheshmeh copper mine,Iran.The underflow solid percent and bed height were expressed as functions of four operating parameters of thickener.Predicted values were found to be in good agreement with experimental values(R2values of 0.992 and 0.997 for underflow solid percent and bed height,respectively).This study has shown that the RSM and CCRD could effciently be applied for the modeling of thickener for dewatering of flotation tailing.

Improvement of xylanase production by Aspergillus niger XY-1 using response surface methodology for optimizing the medium composition

Objective: To study the optimal medium composition for xylanase production by Aspergillus niger XY-1 in solid-state fermentation (SSF). Methods: Statistical methodology including the Plackett-Burman design (PBD) and the central composite design (CCD) was employed to investigate the individual crucial component of the medium that significantly affected the enzyme yield. Results: Firstly, NaNO3, yeast extract, urea, Na2CO3, MgSO4, peptone and (NH4)2SO4 were screened as the significant factors positively affecting the xylanase production by PBD. Secondly, by valuating the nitrogen sources effect, urea was proved to be the most effective and economic nitrogen source for xylanase production and used for further optimization. Finally, the CCD and response surface methodology (RSM) were applied to determine the optimal concentration of each sig-nificant variable, which included urea, Na2CO3 and MgSO4. Subsequently a second-order polynomial was determined by multiple regression analysis. The optimum values of the critical components for maximum xylanase production were obtained as follows: x1 (urea)=0.163 (41.63 g/L), x2 (Na2CO3)=?1.68 (2.64 g/L), x3 (MgSO4)=1.338 (10.68 g/L) and the predicted xylanase value was 14374.6 U/g dry substrate. Using the optimized condition, xylanase production by Aspergillus niger XY-1 after 48 h fermentation reached 14637 U/g dry substrate with wheat bran in the shake flask. Conclusion: By using PBD and CCD, we obtained the optimal composition for xylanase production by Aspergillus niger XY-1 in SSF, and the results of no additional expensive medium and shortened fermentation time for higher xylanase production show the potential for industrial utilization.

Optimization of medium components using response surface methodology (RSM) for mycelium biomass and exopolysaccharide production by <i>Lentinus squarrosulus</i>

The interaction between sucrose, yeast extract and initial pH was investigated to optimize critical medium components for mycelium biomass and production of exopolysaccharide (EPS) of Lentinus squarrosulus using Response Surface Methodology (RSM). A central composite design (CCD) was applied and a polynomial regression model with quadratic term was used to analyse the experimental data using analysis of variance (ANOVA). ANOVA analysis showed that the model was very significant (p Lentinus squarrosulus are as follows: sucrose concentration 114.61 g/L, yeast extract 1.62 g/L and initial pH of 5.81;sucrose concentration 115.8 g/L, yeast extract of 3.39 g/L and initial pH of 6.44 respectively.

Enhacement of the Viability of <i>Lactobacillus</i><i>plantarum</i>during the Preservation and Storage Process Based on the Response Surface Methodology

Objective: The Response Surface Methodology (RSM) is a commonly used system to optimize cell viability of probiotic strains when they are subjected to different preservation and storage processes. Methods and Results: To determine the optimal levels of incorporation of several cry oprotectants (skim milk, sucrose and trehalose) in the freeze-drying process of Lactobacillus plantarum, a range of experiments based on a Rotational Central Composite design (CCD) were conducted. The results were adjusted to a quadratic model, resulting in the presence of interaction between the different variables. Solving a regression equation, we obtained the optimum concentrations of cryoprotective agents: 24.06% milk powder, 6.22% sucrose, 5.63% trehalose. To visualize the interactions between the three variables involved in the study, Design Expert? software was used. Conclusions: The analysis reveals that while trehalose has a direct effect on the viability of L. plantarum, skim milk and sucrose exert quadratic effects. There are also interactions between cryoprotectants, which emphasize the synergies produced between milk and sucrose and between sucrose and trehalose, which allows maintaining the viability of L. plantarum. Significance and Impact of the Study: The addition of new oligosaccharides as trehalose in premixtures for functional feed can maintain the viability of L. plantarum during longer periods of time, ensuring the proper administration of probiotics to their destinations.

Optimization of Dielectric Barrier Discharge Process for Decolorization of Reactive Blue 19 by Means of Response Surface Methodology

The decolorization of reactive blue 19(RB-19)as a model dye from aqueous solutions has been studied by means of the dielectric barrier discharge(DBD)process.The independent parameters of input power,initial dye concentration and initial pH value were evaluated respectively.Experimental data were optimized by means of a 33 factorial design and response surface methodology(RSM).The dye was quickly removed during the treatment,yielding 96.9%of decolorization efficiency under optimized conditions.Therefore,the total organic carbon(TOC)and chemical oxygen demand(CODcr)results indicated that only the chromophore was destroyed rather than completed oxidation.This was confirmed with UV-vis and tertiary butanol assessments during the DBD treatment.

Optimal Evaluation of Coag-Flocculation Factors for Alum-Brewery Effluent System by Response Surface Methodology

This work investigates coag-flocculation optimization treatment of alum-brewery effluent system via response surface methodology (RSM). To minimize suspended and dissolved particles (SDP), experiments were carried out using nephelometric jar test and 23-factorial design with three star-points, six-center-points and two replications. A central composite design, which is the standard design of RSM, was used to evaluate the effects and interactions of three major factors (coagulation pH, coagulant dosage, settling time) on the treatment efficiency. Multivariable quadratic model developed for the response studied indicates the optimum conditions to be 9, 500mg/l and 20minutes for coagulation pH, coagulant dosage and settling time, respectively. At optimum, the SDP was reduced from 10831.490mg/l to 801.451mg/l, representing 92.601% removal efficiency. RSM has demonstrated to be appropriate approach for the optimization of the coag-flocculation process by statistical evaluation.

Optimization of the Impeller Geometry for an Automotive Torque Converter Using Response Surface Methodology and Desirability Function

Response surface methodology (RSM) based on desirability function approach (DFA) is applied to obtain an optimal design of the impeller geometry for an automotive torque converter. The relative importance of six design parameters including impeller blade number, blade thickness, bias angle, scroll angle, inlet angle and exit angle is investigated using orthogonal design approach. The impeller inlet angle, exit angle and bias angle are found to exert the greatest influence on the overall performance of a torque converter, with two flow area factors being considered, namely 17% and 20%. Then, RSM together with central composite design (CCD) method is used to in-depth evaluate the interaction effect of the three key parameters on converter performance. The results demonstrate that impeller exit angle has the strongest impact on peak efficiency, with larger angles yielding the most favorable results. The stall torque ratio maximization is attainable with the increase of impeller bias angle and inlet angle together with smaller exit angle. In the end, an optimized design for the impeller geometry is obtained with stall torque ratio and peak efficiency increased by 1.62% and 1.1%, respectively. The new optimization method can be used as a reference for performance enhancement in the design process of impeller geometry for an automotive torque converter.

Central Composite Design响应面法优化厚裂凤仙花总黄酮提取工艺研究

为厚裂凤仙花中总黄酮资源的开发利用,本文采用单因素与星点-效应面法相结合的方式,考察提取溶剂浓度、料液比、提取时间、提取次数对厚裂凤仙花中总黄酮提取率的影响。优选出厚裂凤仙花总黄酮最佳提取方法为:甲醇体积分数80%,料液比为1︰64,提取时间为50 min;提次数为3次;验证实验结果表明,总黄酮平均提取率为5.51 mg/g,与实验模型RSD值为0.79%。建立的模型与实际方案有较高拟合度,可作为苗药厚裂凤仙花总黄酮提取工艺参数。

星点设计-效应面法优化白及多糖pH-离子敏感原位凝胶的处方

目的优化白及多糖pH-离子敏感原位凝胶的处方。方法以去乙酰结冷胶用量、海藻酸钠用量、氯化钙用量、枸橼酸钠与氯化钙的质量比为考察变量,采用单因素实验初步确定各变量的范围。以25℃凝胶前体溶液黏度和37℃胶凝黏度为考察指标,采用星点设计-效应面法优选白及多糖pH-离子敏感原位凝胶的处方工艺,并进行预测分析。结果白及多糖pH敏感原位凝胶的最优处方为:去乙酰结冷胶用量为0.50%,海藻酸钠用量为1.10%,氯化钙用量为0.07%,枸橼酸钠与氯化钙的质量比为4∶1。该处方条件下,25℃前体溶液黏度为(704.00±3.00)mPa·s,37℃胶凝黏度为(12544.70±47.33)mPa·s。结论白及多糖pH-离子敏感原位凝胶稳定性好,前体溶液在25℃流动性良好,凝胶强度良好,可为基于白及多糖原位凝胶的后续研究提供实验基础。

层次分析-熵权法联合星点设计-响应面法优选胆汁制陈皮炮制工艺及饮片色度与成分相关性分析

目的研究胆汁制陈皮炮制的最佳工艺参数,明确饮片色度与主要成分之间的关系。方法采用星点设计-响应面法,以辅料用量、蒸制时间、干燥时间、干燥温度为考察因素,以橙皮苷、川陈皮素、橘皮素、牛磺胆酸钠含量及外观性状、醇浸出物含量为评价指标,采用层次分析-熵权法对各评价指标赋予相应权重,计算总评归一值,优选最佳炮制工艺;采用相关性分析和回归分析研究饮片色度与主要有效成分含量的相关性,构建色度-成分的回归方程。结果胆汁制陈皮最佳炮制工艺为每100g陈皮用20g蛇胆汁浸渍完全后,蒸制15min,45℃干燥162min。饮片色度值L^(*)、b^(*)值与橙皮苷、川陈皮素、橘皮素、牛磺胆酸钠4种成分含量均具有显著相关性,a^(*)值仅与牛磺胆酸钠含量具有相关性;构建了L^(*)、b^(*)值与4种成分含量及a^(*)值与牛磺胆酸钠含量的线性回归方程。结论采用星点设计-响应面法优化的胆汁制陈皮炮制工艺具有合理性、可行性,饮片色度与成分含量具有显著相关性。

星点设计-效应面法优选复方山陈颗粒成型工艺

目的优选复方山陈颗粒的成型工艺。方法单因素试验筛选出稠膏的相对密度、稀释剂总用量为考察因素,以颗粒的成型率、休止角、水分和溶化性为评价指标,采用星点设计-效应面法(CCD-RSM)优选复方山陈颗粒的最佳成型工艺。结果最佳成型工艺条件为取相对密度为1.25(60℃)的稠膏与稀释剂(甘露醇:糊精=1:3)按1:3的比例混匀,制软材,过16目筛制粒,在60℃下干燥约1 h,整粒,即得。结论通过CCD-RSM优选的工艺稳定可靠,可为复方山陈颗粒的产业化生产提供参考。

Optimization and characterization of nimesulide bilayer tablets by response surface methodology

The objectives of this present investigation were to develop and formulate nimesulide bilayer tablets by using different polymer combinations and fillers, to optimize the formulations for different drug release variables by orthogonal design and central composite design-surface methodology and to evaluate drug release pattern of the optimized product. The bilayer tablet containing a fast release layer（FRL） and a sustained release layer（SRL） provided an initial burst release of nimesulide, followed by the sustained release for a period of time. The optimal formulation obtained was as follows：（I） the formulation of FRL： nimesulide, 50 mg; lactose, 92 mg; starch, 22 mg; CCMC-Na, 14 mg; PVP K30, 1 mg; micronized silica gel, 1 mg; magnesium stearate, 0.9 mg; and iron oxide red, 0.1 mg; and（II） the formulation of SRL： nimesulide, 150 mg; HPMC K100LV, 26 mg; HPMC K4M, 33 mg; lactose, 54 mg; PVP K30, 1 mg; micronized silica gel, 1 mg; and magnesium stearate, 0.9 mg. According to the optimal formulation, the biphasic type of release was identified. The in vitro drug dissolution from the bilayer tablets was sustained for about 16 h after releasing 15% of drug in the first 10 min. The developed nimesulide bilayer tablets with improved efficacy can perform therapeutically better than the conventional tablets.

白簕多糖颗粒剂的制备工艺研究

目的 研究白簕多糖颗粒的制备工艺。方法 采用湿法制粒工艺制备颗粒,以成型率、休止角、溶化性作为颗粒剂制备工艺的考察指标。应用单因素法考察多糖与稀释剂配比、润湿剂浓度与用量、干燥温度、干燥时间对颗粒剂质量的影响;在此基础上,以多糖与稀释剂配比、润湿剂浓度、润湿剂用量为考察因素,采用星点设计-响应面法优化处方,并进行工艺验证,计算综合评分评估制备工艺的可行性。结果 最优制备工艺为:赤藓糖醇与白簕多糖配比为3.22:1、润湿剂乙醇浓度为73.68%、乙醇用量为17.51%,在该条件下制备的白簕多糖颗粒剂的成型率达93.60%,休止角为28.20°,溶化率达98.12%,平均综合评分为97.24。制得的白簕多糖颗粒剂在外观、粒度、水分、总糖含量等方面均符合2020年版《中国药典》颗粒剂项下要求。结论 该制备工艺稳定可行,质量可靠。

星点设计-效应面法优化仑伐替尼混合胶束的制备工艺

目的优化仑伐替尼混合胶束的处方及其制备工艺。方法以Pluronic P123和F127作为载体材料,通过薄膜水化法制备仑伐替尼混合胶束。利用单因素实验和星点设计-效应面法筛选出最优处方并对其物理性质进行初步表征。结果优化后的最佳处方和工艺条件为:P123质量百分比80%、载体材料用量90 mg、投药量10 mg、水化体积6 ml、水化时间45 min、旋蒸温度55℃。制备得到的仑伐替尼混合胶束的平均粒径为(104.0±0.32)nm,PDI为0.22±1.19,Zeta电位为(-2.56±0.81)mV,平均包封率为83.33%±0.30%,平均载药量为8.67%±0.07%。胶束形态为分布均一的规整球形,并显示出一定的缓释性能。结论该研究开发的制备工艺简单可行,所得载药胶束具有较高的载药量和包封率且释放稳定,为仑伐替尼混合胶束的进一步研究和开发提供了有价值的参考。

罗非鱼抗凝血口服液的制备及其稳定性的初步研究

采用星点设计-效应面法分别优化风味蛋白酶、胰凝乳蛋白酶和木瓜蛋白酶水解罗非鱼肉的工艺条件。然后,在每种酶各自最佳条件下对罗非鱼肉进行混合酶水解,以凝血酶滴定改进法测定混合水解液的抗凝血活性。实验结果表明,在胰凝乳蛋白酶的最佳条件下,“风味蛋白酶-胰凝乳蛋白酶-木瓜蛋白酶”混合酶解组合的抗凝血活性最高,其活性为48.0 ATU/mL。通过添加适量的防腐剂和矫味剂将酶解液制备成具一定抗凝血活性和口感风味良好的口服液。口服液的稳定性试验的结果表明:口服液需要在pH值在6.5~7.0之间和4℃的低温环境下储存。

星点设计-效应面法优化超声提取桂籽中三萜化合物的工艺研究

目的本研究以桂籽为原材料,采用星点设计(CCD)-效应面法(RSM)等多种方法优化桂籽总三萜(OFSTT)的提取工艺及其含量测定研究。方法采用单因素、Plackett-Burman(PB)、最陡爬坡和CCD-RSM实验,建立各因素与响应值之间的数学模型,确定OFSTT的最佳超声提取工艺。结果通过单因素试验,得到了关于桂籽总三萜含量变化的趋势线,进一步利用PB实验筛选出对OFSTT产生显著影响的因素(提取功率、液料比及提取次数),通过最陡爬坡实验设计出极值点,以此作为效应面设计的中心点,采用星点设计-效应面法优化了OFSTT提取工艺的最佳提取工艺条件:乙醇溶剂分数60%,液料比25∶1(mL/g),提取温度65℃,提取功率325W,提取时间30min,提取3次;该条件下OFSTT的提取率为7.251%,实际值与预测值的偏差为2.05%。结论本研究采用CCD-RSM实验优化了OFSTT的提取工艺,该工艺稳定,提取率较高,实际值与预测值吻合度高,为后续桂籽三萜类物质进一步结构鉴定及生物活性作用研究提供参考价值。

基于响应面法的半主动悬架天棚控制算法优化

以CDC减振器阻尼系数可调范围为基础,建立连续天棚控制算法,并结合整车多体动力学模型,搭建整车半主动悬架的阻尼控制联合仿真模型。为优化控制算法中前后悬架天棚阻尼系数,首先建立平衡乘坐舒适性和操纵稳定性的综合评价指标,指标由连续中小激励的悬架隔振指标、单个脉冲激励的悬架降振指标、角阶跃的悬架响应指标组成。其次,采用中心复合有界设计定义试验设计策略,通过仿真计算综合评价指标,构建优化变量与综合评价指标之间的二次响应面模型,以综合评价指标最小为优化目标,优化后的前、后悬架天棚阻尼系数分别为5.39、3.61 Ns/mm。最后,通过仿真对比验证,优化后的连续天棚控制算法,在确保与被动悬架操纵稳定性相当的前提下,可大幅提升乘坐舒适性,连续中小激励下悬架隔振舒适性提升20.44%,单次脉冲激励下悬架冲击舒适性提升56.67%。