Mixture Experimental Design Research Articles

Liquisolid pellets: Mixture experimental design assessment of critical quality attributes influencing the manufacturing performance via extrusion-spheronization

A Quality by Design approach was taken to assess the influence of several formulation parameters on critical quality attributes of liquisolid pellets (LPs) obtained by extrusion-spheronization. Two mixture experimental designs were used, one for each of the non-volatile solvents (NVS) studied: Kolliphor® EL or PEG 400. The studied parameters were the concentrations of NVS (A-Kolliphor® EL, 0–40% w/w; or PEG 400, 0–31.1% w/w), coating material (B-crospovidone, 0–50.3% w/w) and carrier (C-microcrystalline cellulose, MCC, 27–100% w/w). The critical quality attributes assessed were amount of granulation liquid required for extrusion/spheronization, residual moisture, particle size, particle size distribution, bulk density, tapped density, true density, Carr's Index, Hausner Ratio, aspect ratio, angle of repose and friability. All hierarchical terms and interactions were evaluated to determine the statistical relevance of each term. Mathematical models were determined by linear regression, taking into account statistically relevant terms. Lack of Fit, R2, adjusted R2 and adequate precision were assessed to determine the fitness of each mathematical model. It was possible to identify and understand parameters affecting critical quality attributes of LPs, as well as the magnitude of these effects. The mathematical models developed were robust and can be used to predict optimal LPs excipient compositions within the experimental domains assessed. This study provides an overall understanding of the impact of excipients on quality attributes of blank LPs, a critical knowledge to the implementation of this novel application of liquisolid systems.

Model-robust design of mixture experiments

Optimal designs are often used for constrained mixture experiments because of the irregular design spaces. For these experiments, the number of blends needed to fit standard linear models may be too large when considering second- or third-order terms. We present a computationally-tractable algorithm for generating model-robust mixture designs that exploits anticipated effect sparsity by using a set of models defined by a user-specified number of higher-order terms. We compared the model-robust designs with Bayesian-optimal designs, and the model-robust designs show an improved ability to either estimate realistic models or make predictions for mixture experiments.

Measurement in some properties of non-toxic particleboard to optimize the formulation for food containers

Optimizing a formulation of particleboard, contained rubberwood sawdust (RWS), palmyra fruit fiber (PFF) and tapioca starch (TS), was done by applying the mixture experiment design to achieve the maximum modulus of rupture (MOR) and internal bond strength (IBS), and minimum water absorption (WA). The materials were processed into particleboard panels using a hot compression machine. Analysis of variance revealed that all compositions significantly affected the MOR, IBS and WA characteristics. The increasing additions of palmyra fruit fiber in the particleboard increased the MOR and WA values but decrease the IBS. The MOR and WA characteristics were improved with an increase of the tapioca starch content. An optimal formulation of particleboard was found to be 64% RWS, 20% PFF and 16% TS. The particleboard produced from the optimal formulation apart from meeting the Japanese Industrial Standard requirements in Type 8 can also be processed efficiently as wooden boxes for food containers.

Omega-3 Self-Nanoemulsion Role in Gastroprotection against Indomethacin-Induced Gastric Injury in Rats.

Peptic ulcer disease is an injury of the alimentary tract that leads to a mucosal defect reaching the submucosa. This study aimed to formulate and optimize omega-3 oil as a self-nanoemulsifying drug delivery system (SNEDDS) to achieve oil dispersion in the nano-range in the stomach to augment omega-3 oil gastric ulcer protection efficacy. Three SNEDDS components were selected as the design factors: the concentrations of the oil omega-3 (X1, 10–30%), the surfactant tween 20 and Kolliphor mixture (X2, 20–40%), and the cosurfactant transcutol (X3, 40–60%). The mixture experimental design proposed twenty-three formulations with varying omega-3 SNEDDS formulation component percentages. The optimized omega-3 SNEDDS formula was investigated for gastric ulcer protective effects by evaluating the ulcer index and by the determination of gastric mucosa oxidative stress parameters. Results revealed that optimized omega-3-SNEDDS achieved significant improvement in the gastric ulcer index in comparison with pure omega-3 oil. Histopathological findings confirmed the protective effect of the formulated optimized omega-3 SNEDDS in comparison with omega-3 oil. These findings suggest that formulation of omega-3 in the form of a SNEDDS would be more effective in gastric ulcer protection than the administration of omega-3 as a crude oil.

Theoretical and experimental investigations on the combustion characteristics of three components mixed municipal solid waste

The combustion characteristics of Mixed Municipal Solid Waste (MMSW) play a vital role in dictating the efficiency of the incineration process. At present, few studies on combustion characteristics of three components MMSW and the establishment of corresponding comprehensive kinetic model of single component waste have been reported. In the present study, based on the law of mass action and Badzioch's relation, the mathematical expressions for describing the TG (Thermogravimetric) curves and the DT (Differential thermal) curves of single component MMSW are derived. A comprehensive kinetic model for the combustion characteristics of single component MMSW is developed and the appropriateness of the model is confirmed by the experimental results. The calculated TG curves closely agree with the experimental curves; the maximum deviation between the experimental and calculated curves is within 5%. Based on the principle of mixture experiments, the co-combustion characteristics of MMSW composed of food bag, disposable chopstick and cotton cloth are studied by using TGA (Thermogravimetric Analysis) and DTA (Differential Thermal Analysis). It has been found that the activation energy of three components MMSW is lower than that of single component. Finally, based on multiple regression analysis for the design of mixture experiments and the corresponding data, an empirical formula for calculating activation energy of three components MMSW is obtained. The experimental and calculated values match closely; the maximum deviations between them is within 7%. The empirical formula provides a robust way to calculate activation energy of three components MMSW.

Evaluation and optimization of functional and antinutritional properties of aquafaba

AbstractEgg protein is responsible for the second most serious of all food allergens, which affects predominantly the children. Therefore, a new type of vegan ingredient called “aquafaba,” is getting recognized as a plant‐based emulsifier in many bakery product preparations instead of the conventionally used egg white and is emerging in the consumer market. It is the residue water from cooked chickpeas. In this study, an I‐optimal mixture experimental design is combined with a response surface methodology to evaluate the chickpeas cooking process for obtaining aquafaba. The following variables were used: chickpea to cooking water ratio (CPCWR; 1:2, 1:4, and 2:3) and cook time (15, 30, 45, and 60 min). The principal goal was to maximize the functional properties and protein content, while minimizing tannin and phytate contents of aquafaba. The results showed that both CPCWR and cooking time had significant effect on the responses. Emulsion properties were the maximum at 2:3 CPCWR and cooking time of 60 min. Foaming capacity was highest (120%) at 2:3 CPCWR cooked for 30 min, whereas the foam was most stable (57 min) at 1:2 CPCWR with 45 min cooking. Water holding capacity reached the maximum level when cooked for 15 min, and oil holding capacity maximum was obtained after 60 min cooking. Polynomial models were developed for all 11 responses. Optimal results were achieved under the following conditions: 1.5:3.5 CPCWR and 60 min cook time, and the overall desirability fraction was 0.81. Validation tests confirmed these results.

Influence of Ternary Emulsifier Mixtures on Oxidative Stability of Nanoemulsions Based on Avocado Oil.

The aim of this work was to study the effect of two emulsifiers (M1: SL-soy lecithin, Tw80-Tween 80 and CasCa-calcium caseinate and M2: SL-soy lecithin, Tw80-Tween 80 and SE-sucrose esters) on the oxidative stability of avocado oil-based nanoemulsions. Oil-in-water nanoemulsions were prepared using 3.6% w/w of two emulsifier mixtures, which were optimized by mixture experimental design in order to minimize particle size (PS) and polydispersity index (PdI). Then, the oxidative stability of nanoemulsions was evaluated through both an induction period and a quantification of hydroperoxides and thiobarbituric acid reactive species (TBARs) under accelerated storage conditions. The simplex-centroid mixture design showed that PS and PdI varied when proportions of different emulsifiers were modified, obtaining an optimized concentration for each mixture of: 85% SL, 10% Tw80 and 5%CasCa (M1) and 85% SL, 7.4% Tw80 and 7.6% SE (M2) that produced nanoemulsions with PS ~116 nm and PdI < 0.2. Nanoemulsions elaborated with M1 and M2 presented similar particle characteristics and physical stability to the control sample with Tw80. However, M1 nanoemulsions were more stable against lipid oxidation, since they showed the highest induction period and lower formation of hydroperoxides and TBARs during storage.

Spray drying process of extract of Wenjing Zhitong Prescription based on mixture design experiment

To improve the spray drying effect of extract of Wenjing Zhitong Prescription, this study takes the yield, hygroscopic property and the fluidity of dry powder as indexes to screen out auxiliary materials, and the proportion of the auxiliary materials was optimized based on the mixing design experiment; based on that, HPLC method was established for the determination of glycyrrhizin and 6-gingerol in spray powder, the yield of spray powder and the retention rate of the two index components were taken as indexes to further optimize the spray drying parameters. The finally selected auxiliary materials were light magnesium oxide, maltodextrin and silica, and regression equations of dry powder yield, moisture absorption rate, angle of rest with proportion of auxiliary materials were established, and the optimized proportion of auxiliary materials was dry paste-light magnesium oxide-maltodextrin-silica=0.5∶0.305∶0.145∶0.05; according to the optimized drying process parameters of Wenjing Zhitong Prescription, initial temperature was 60 ℃, air inlet temperature was 130 ℃, air flow rate was 35 m~3·h~(-1), atomizing pressure was 40 mm, and liquid inlet speed was 4.5 mL·min~(-1). Under these conditions, the dry powder yield was 90.28%, the retention rate of glycyrrhizin was 74.51%, and the retention rate of 6-gingerol was 72.10%. In this study, optimized auxiliary materials can improve the yield of spray drying and the property of spray powder, and the optimized processing conditions were good for retaining the unstable gingerol components, which can lay a foundation for the further preparation research of meridian warming and pain relieving prescriptions, and provide reference for extract of other traditional Chinese medicine extracts that are difficult to spray drying.

Effect of clay loading on the water resistance of ternary-filled natural rubber composites

Water immersion was performed on 13 natural rubber (NR) composites filled with varying proportions of carbon black (CB), organically-modified bentonite (M−BNT) and raw bentonite (BNT), to determine the effect of clay loading on the water barrier properties of ternary-filled NR composites. These composites were prepared using a third-degree simplex lattice mixture design of experiment. Specimens were immersed at 80℃ deionized water for 1200 h to measure their percentage water uptake and diffusion coefficient. Results showed that mixing 2.5 phr M−BNT and 2.5 phr BNT to 10 phr of CB provides outstanding water resistance to NR composites. It improved the percentage water uptake by 25.07% and diffusion coefficient by 41.12% as compared to pure CB filler (15/0/0). However, increase in clay loading to pure M−BNT (0/15/0) and pure BNT (0/0/15) led to poor water resistance due to aggregation of fillers. But this observation is less pronounced in M−BNT due to its increased hydrophobicity as a result of organic modification. Contour plots generated from reduced hierarchical models were able to give a graphical representation of the observed results. High values of coefficient of determination with values of 95.40% and 90.15% were computed for percentage water uptake and diffusion coefficient, respectively.

Feasibility of electrospraying fully aqueous bovine serum albumin solutions

Electrospraying or electrohydrodynamic atomisation, i.e. the formation of tiny droplets from a jet of conductive liquid under the influence of an electric field, has been gaining in popularity as a particle engineering technique in recent years. In addition to general benefits for particle engineering, e.g. the ability to generate nanometre sized particles with a very narrow size distribution, electrospraying also possesses a number of characteristics, like its applicability at ambient conditions, which could make it especially interesting for formulating therapeutic proteins. However, as fully aqueous solutions of proteins tend to have relatively high electrical conductivities and surface tensions, obtaining a stable Taylor cone-jet mode for these solutions is inherently challenging. This is why in the majority of studies reporting the successful electrospraying of proteins, either emulsions, aqueous suspensions or a mixture of water and one or more organic solvents were used instead of fully aqueous solutions. Therefore, an ab initio electrospraying formulation development study was conducted, using only fully aqueous feed solutions containing protein stabilising excipients commonly used in spray- and freeze-drying of therapeutic proteins. The study included bovine serum albumin (BSA) as a model protein and consisted out of two parts: (1) a one parameter at a time screening study, designed to improve the understanding of how various formulation components influence relevant physicochemical properties and the electrospraying process and (2) two subsequent mixture design of experiments (DoE) studies, designed to aid in the statistical description and prediction of the influence of different protein-excipient combinations on the electrospraying process. Additionally, the influence of physicochemical properties relevant to the electrospraying process, i.e. the volumetric mass density, electrical conductivity, kinematic viscosity and surface tension, was assessed for all feed solutions included in the study.

Modelling and Optimization of the Wear rate, Compressive Strength and Hardness of a Composite Brake Pad

A composite brake pad of periwinkle shell, phenolic resin and other additives was developed. The mixture design experiment was adopted using the Design Expert 10.0 software 2017 version and the sample composites were produced using compression molding. Mathematical models of the wear rate, compressive strength and hardness values were developed and validated. The models for the wear rate and compressive strength fitted best with the quartic response model while that of the hardness suited best with quartic and linear models. Comparison of the models with experimental results graphically showed high degree of correlation. An optimized formulation with an objective of minimization of the wear rate and maximization compressive strength and hardness value was determined at 50, 30 and 20% of periwinkle shell powder (filler), phenolic resin (matrix) and additives respectively. Thus the mathematical model can be used to predict the wear rate, compressive strength and hardness value of the experimental design adopted.Key words: periwinkle shell; composite brake pad; quartic mathematical model; wear rate; compressive strength; hardness value; mixture design

Development of cyclosporine-loaded nanoemulsion for topical treatment of psoriasis

Psoriasis is an autoimmune disease in which the symptoms are obviously appeared on the patient's body with thick, red/ salmon colour and dry patches. Clinically, topical treatment has been the first-line treatment for psoriasis, whether or not the systemic and phototherapy is required. Currently, cyclosporine is one of the standard oral medications used for moderate to a severe case of psoriasis. However, through oral delivery, it cannot be used for a long period and causes bad effects. Thus, a new delivery system of cyclosporine is in need to be developed to overcome its toxic effects by skipping the first pass body metabolism. A nanoemulsion colloidal system, as the main carrier for big, non-water-soluble cyclosporine, is believed could help in the delivery of activities through the stratum corneum of the skin layer. Nanoemulsion system, which mainly consists of oil phase (a mixture of virgin coconut oil, nutmeg oil, and cyclosporine), aqueous phase, and surfactant, was successfully being developed by using Mixture Experimental Design optimization tool with droplet size range between 110-160 nm. Stability studies were carried out with respect to; pH, storage at different temperatures, coalescence and Ostwald ripening mechanism, free-thaw cycle, and FTIR analysis. From the obtained results, this newly-developed nanoemulsion containing cyclosporine was proven to be stable and successfully maintained its physicochemical characteristics even after 3 months of storage at 4°C and 25°C temperature. Ostwald ripening mechanism contributed to the instability of the system at 45°C of storage. Introduction of standard cyclosporine, blank nanoemulsion, and nanoemulsion containing cyclosporine to the HaCaT cells in the treatment of MTT assay study has confirmed the safety of the nanoemulsion. Permeation study of the newly-developed nanoemulsion containing cyclosporine showed it was best fitted the Korsmeyer-Peppas kinetic model. In addition, the transepidermal water loss and hydration studies proved the efficacy of cyclosporine-loaded nanoemulsion in increasing the water storage of the volunteers’ normal skin after 3h of application.

Application of a mixture DOE for the prediction of formulation critical temperatures during lyophilisation process optimisation.

During lyophilisation cycle design, primary drying parameters (chamber pressure and shelf temperature) are adjusted to maximize the sublimation rate and prevent cake collapse, by maintaining the product continuously below its critical temperatures. The objective of this study was to employ mixture design of experiments to generate empirical models capable of predicting glass transition of the maximally freeze concentrated solution (Tg') and collapse temperature (Tc) of amorphous protein (BSA and IgG1) formulations. Additionally, the models developed aid the design of high concentration protein formulations with maximised critical temperatures to obtain shorter and more cost-effective lyophilisation cycles. Formulations contain sucrose as cryo/lyo-protectant and arginine/arginine-HCl as multifunctional excipient (e.g. solubility enhancer, viscosity and aggregation suppressor). The impact of formulation components at varied ratios on critical temperatures was evaluated; the amorphous excipients decrease critical temperatures, on the contrary, the protein increases critical temperatures. The robustness of the empirical models generated with BSA formulations was verified with BSA and IgG1 formulations. The models showed greater accuracy in predicting Tg' than the Fox-Flory equation. For the first time, empirical models are reported to predict both critical temperatures. Finally, unconventional collapse events observed for formulations with and without arginine/arginine-HCl at different protein concentrations are also discussed.

Effect of agro-industrial residues mixtures on the production of endoglucanase by Aspergillus niger in solid state fermentation

The low-cost production of cellulolytic complexes that present high action at mild conditions is one of the major bottlenecks for the economic viability of the production of cellulosic ethanol. The influence of agro-industrial residues was assessed to enhance endoglucanase production by Aspergillus niger 426 grown in solid state fermentation. The highest percentage of lignin degradation was found on soybean hulls (56%) followed by sugarcane bagasse (36%) and rice straw (8.5%). The cellulose degradation, around 90%, was observed on soybean hulls and sugarcane bagasse, but only 50% on rice straw, and maximum production of endoglucanase (112.34 ± 0.984 U mL-1) was observed for soybean hulls. The best Experimental Mixture Design condition was under cultivation of 2.5 g of sugarcane bagasse, 2.3 g of rice straw and 5.2 g of soybean hulls, leading to a maximum activity of 138.92 ± 0.02 U mL-1. The statistical methodology enabled an increase of over 20% in the production of endoglucanase using agro-industrial waste. These data demonstrate that A. niger 426 is a potential source of cellulases which can be obtained by solid state fermentation using agro-industrial waste.

Synthesis of Geopolymer from Blends of Tropical Biomass Ashes

Thermal conversion of biomass to produce energy inevitably generates ash as residual matter. Therefore, sustainable utilization of biomass should also consider reuse measures for the ash. This research examines the conversion of locally available biomass ashes in Indonesia into geopolymer. This is an environmentally more benign alkali-aluminosilicate alternative to the ordinary Portland cement produced by low-temperature reactions between aluminosilicates and concentrated alkali solution. Biomass ash sources in this study are corn stover, coconut shell, and sugarcane bagasse. Biomass ash blends are prepared according to a ternary simplex centroid mixture experiment design. These blends are reacted with activator solutions containing NaOH and Na-silicate and blended with sand aggregate to produce geopolymer mortar specimens. Early compressive strengths of geopolymer mortars range from 7.2 to 10.4 MPa, which surpasses the SNI 15-2049-2004 national standard for Portland cement with low heat of hydration. Statistical analysis of the experimental data indicates that the early strength as a function of biomass ash blend formulation is represented by a quadratic mixture model. Bagasse ash produces the highest strength. The quadratic terms consist of bagasse-corn and bagasse-coconut antagonistic blending terms. Morphology of the geopolymer mortar fracture surface indicates good bonding with the sand aggregate. Extensive acicular crystal growth within the amorphous geopolymer gel phase is observed in lower-strength formulations, which points to the formation of zeolite-like phase in the geopolymerization process. While the correlation of biomass ash type to the structure of the resulting geopolymer is yet to be established, this work has clearly identified the technical feasibility of producing geopolymer with satisfactory strength from tropical biomass ashes.

Influence of blends of diesel and renewable fuels on compression ignition engine emissions over transient engine conditions

To reduce the amount of carbon dioxide released from transportation the EU has implemented legislation to mandate the renewable content of petrol and diesel fuels. However, due to the complexity of the combustion process the addition of renewable content, such as biodiesel and ethanol, can have a detrimental effect on other engine emissions. In particular the engine load can have a significant impact on the emissions. Most research that have studied this issue are based on steady state tests that are unrealistic of real world driving and will not capture the difference between full and part loads. This study aims to address this by investigating the effect of renewable fuel blends of diesel, biodiesel and ethanol on the emissions of a compression ignition engine tested over the World Harmonised Light Vehicle Test Procedure (WLTP). Diesel, biodiesel and ethanol were blended to form binary and ternary blends, the ratios were determined by Design of Experiments (DoE). The total amount of emissions for CO, CO2 and NOx as well as the fuel consumption, were measured from a 2.4 L compression ignition (CI) engine running over the WLTP drive cycle. The results depicted that percentages smaller than 10% of ethanol in the fuel blend can reduce CO emissions, CO2 emissions as well as NOx emissions, but increases fuel consumption with increasing percentage of ethanol in the fuel blend. Blends with biodiesel resulted in minor increases in CO emissions due to the engine being operated in the low and medium load regions over the WLTP. CO2 emissions as well as NOx emissions increased as a result of the high oxygen content in biodiesel which promoted better combustion. Fuel consumption increased for blends with biodiesel as a result from biodiesel’s lower heating value. All the statistical models describing the engine responses were significant and this demonstrated that a mixture DoE is suitable to quantify the effect of fuel blends on an engine’s emissions response. An optimised ternary blend of B2E9 was found to be suitable as a ’drop in’ fuel that will reduce harmful emissions of CO emissions by approximately 34%, NOx emissions by 10% and CO2 emissions by 21% for transient engine operating scenarios such as the WLTP drive cycle.

An experimental approach to design self-consolidating concrete

This paper presents the analysis of an experimental mixture design approach for self-consolidating concrete (SCC) based on two design parameters to optimize mechanical properties and durability. The first approach is based on an empirical determination of the self-consolidation ability of mixtures with a fixed mortar content, while the second approach is based on enhancing the aggregate packing. The proposed procedures enable the establishment of a mixture design nomogram that can correlate the materials’ composition and properties. The effect of mixture design parameters on hardened properties of investigated mixtures developed using each of the proposed approaches was compared in terms of compressive strength to secure a given modulus of elasticity, ultrasound wave propagation velocity and rapid chloride ion penetration. The modulus of elasticity and ultrasound wave propagation velocity of the designed SCC mixtures are found to be, respectively, almost 50% and 8% higher than those of conventional concrete, even at SCC mixtures with lower compressive strength values. Lower modulus of elasticity and ultrasound wave propagation velocity were obtained for SCC mixtures than conventional concrete with compressive strength between 50 and 60 MPa.

Adsorption of pharmaceutical residues on adsorbents prepared from olive stones using mixture design of experiments model.

In this work, inexpensive and easily available olive stone (OS) waste was used as the source material to prepare activated carbons (ACs) by chemical activation with phosphoric acid and zinc chloride. The mixture design of experiments (MDOE) method was applied to study the effect of the composition of the mixture of unmodified olive stones (UOS) and ACs prepared from olive stones activated with ZnCl2 (ACOS ZnCl2) and H3PO4 (ACOS H3PO4) on the absorption of pharmaceutical residues. The adsorbed tetracycline (TC) amounts at equilibrium predicted from the model equation developed using Microsoft Excel were found to be in good agreement with the experimental values (R2 = 0.999). Based on the results of the model, the amount of TC removed increased as the proportion of ACOS H3PO4 in the adsorbent mixture increased and the highest amount of TC adsorbed was obtained with an adsorbent made up entirely of ACOS H3PO4. Separate adsorption tests for sulfamethazine (SMT) and amoxicillin (AMX) on ACOS H3PO4 showed that SMT was adsorbed best (189.81 mg/g), followed by TC (183.11 mg/g) then AMX (155.69 mg/g). However, when these molecules were present together in the same solution, it was TC that adsorbed best, followed by SMT then AMX. In addition to this, the sorption process studied was best described by a pseudo-first-order model and it was the Langmuir model that satisfactorily described the equilibrium data.

Mechanical Properties of Ternary-Filled Natural Rubber Composites

The aim of this study was to investigate the effect of each ternary filler component: carbon black (CB), modified bentonite (M-BNT), and raw bentonite (BNT), and their interactions, on the mechanical properties of natural rubber (NR) composites, using a third degree-simplex lattice mixture design of experiment. The efficiency of the two-step organic modification to produce M-BNT was confirmed by the results of Fourier transform infrared with attenuated total reflectance (FTIR-ATR) spectroscopy and x-ray diffraction (XRD) analysis. Synergistic effect between CB and M-BNT on the mechanical properties of NR composites with ternary filler composition 10/5/0 was observed. Reinforcement of NR matrix using this ternary filler enhanced its tensile properties: strength (69.43%), modulus (47.01%), stress at 100% strain (34.67%), stress at 200% strain (41.88%), and stress at 300% strain (50.82%), as well as its compressive properties: strength (40.89%), modulus (40.05%), stress at 20% strain (41.10%), stress at 40% strain (37.57%), and stress at 60% strain (40.79%). Significant improvement in the mechanical properties was also attributed to the surface modification of M-BNT resulting to better dispersion to NR matrix. The addition of pure BNT filler resulted to lowest tensile and compressive performance due to high clay loading and incompatibility with NR matrix. Trends of the generated contour plots based on reduced hierarchical models demonstrated synergy between CB and M-BNT as well as deterioration of mechanical properties upon addition of pure BNT filler 0/0/15.

A prototype of a low-cost eyelid cleaning foaming solution for symptom management in patients with chronic blepharitis: An I-optimal mixture experimental design

lepharitis is a common chronic eye condition that causes eyelid inflammation, leading to inflamed, irritated, sticky and itchy eyelids and flaking of the skin. For its treatment, patients often need indefinite use of an eyelid cleaning solution which usually cost more than 20 USD per 80 ml bottle and lasts, on average, one month. For those patients unable to afford the treatment, physicians recommend the use of a do it yourself (DIY) solution. However, the efficacy of DIY eyelid solutions might fluctuate according to the type of blepharitis present in the patient and inadequate pH stabilization of the solution might promote additional itchiness, irritation, and dryness of the skin and eyes. Thus, we propose an optimized DIY solution prototype for symptom management in patients with chronic blepharitis. The formulation contains a significant ratio of tea tree oil and resulted in suitable pH and foam expansion values. The low cost and ease of preparation of the designed formulation make it an affordable, effective alternative in the treatment of chronic blepharitis.