Investigation of flow behaviour in the nozzle of a Pelton wheel: Effects and analysis of influencing parameters

The performance of a Pelton wheel is influenced by the jet created by the nozzle. Therefore, a Computational Fluid Dynamics (CFD) simulation was proposed. In this study, the significant output parameters (outlet velocity, outlet pressure, and tangential force component) and input parameters (different pressure and spear locations) were examined. In addition, the influencing parameters and their contributing percentages to the performance of the Pelton wheel were calculated using different optimisation techniques such as Taguchi Design of Experiments (DoE), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), Grey Relational Analysis (GRA) and Criteria Importance Through Intercriteria Correlation (CRITIC). The effect of input factors on the output response was examined with DoE, and the results show that the inlet pressure had the most significant impact (97.38%, 99.18%, and 97.38%, respectively, for all different spear sites with a 99% confidence level). In terms of preference values, the TOPSIS and GRA results are comparable (best ranks for simulation runs #24 and #25 and least ranks for simulations #2 and #3, respectively). The CRITIC results for the pressure parameter are in good agreement with the Taguchi ANOVA analysis. The last spear location (5 mm after the nozzle outlet), with an inlet pressure of 413685 Pa generated the best result when employing the TOPSIS and GRA techniques. The outlet pressure of the nozzle was found to have a significant impact on the flow pattern of the Pelton Wheel based on the analysis of the CRITIC, Taguchi, and CFD results.

Design of experiment-oriented development and validation of novel bioanalytical reverse phase high performance liquid chromatography method of palbociclib in rat plasma and tissues, and its application in pharmacokinetic studies

The current research involved the development and validation of an easy, cost-effective, and sensitive bioanalytical reverse-phase high-performance liquid chromatography method for the assessment of palbociclib (PAL) in rat plasma and kidney, liver, spleen and heart. A response surface methodology-based Box-Behnken design was used to optimize critical chromatographic conditions such as buffer pH, organic phase concentration and flow rate to attain good sensitivity, tailing factor and retention time. The conditions were: pH of buffer, 4.5; organic phase concentration, 40%; Shimpac column with 1.0 ml/min flow rate. The responses were: tailing factor, 1.29 ± 0.03, sensitivity, 366,593 ± 8,592; and retention time, 4.5 ± 0.05 min. The samples were extracted by a protein precipitation method, and absolute recoveries were in the range of 88.99-95.08%. The linearity of the developed method was validated over the range 100-2,000 ng/ml (r2  ≥ 0.994) in all tested matrices. The developed bioanalytical method showed greater accuracy (0.98 and 4.01%) and precision (<4.88%). The method was optimized for the sensitive analysis of the PAL in rat plasma, and the kidney, liver, spleen and heart were effectively applied to pharmacokinetic studies.

The Effect of Processing Conditions on the Microstructure of Homopolymer High-Density Polyethylene Blends: A Multivariate Approach

In this work, a multivariate approach was utilized for gaining some insights into the processing-structure-properties relationships in polyethylene-based blends. In particular, two high-density polyethylenes (HDPEs) with different molecular weights were melt-compounded using a twin-screw extruder, and the effects of the screw speed, processing temperature and composition on the microstructure of the blends were evaluated based on a Design of Experiment-multilinear regression (DoE-MLR) approach. The results of the thermal characterization, interpreted trough the MLR (multilinear regression) response surfaces, demonstrated that the composition of the blends and the screw rotation speed are the two most important parameters in determining the crystallinity of the materials. Furthermore, the rheological data were examined using a Principal Component Analysis (PCA) multivariate approach, highlighting also in this case the most prominent effect of the weight ratio of the two base polymers and the screw rotation speed.

Reclamation of iron and copper from BCL slag in Botswana

High-grade copper ores have been depleted over the years, making it a challenge in the mining industry. This investigation focused on a methodology to recover iron (Fe) and copper (Cu) from a copper/nickel slag obtained from the Bamangwato Concession Limited (BCL) mine in Botswana. In this modified flotation approach, the Response Surface Methodology (RSM) was used in conjunction with the Central Composite Design (CCD) and Analysis of Variance (ANOVA) to obtain the best optimal flotation conditions for the recovery of iron and copper. Using the RSM - CCD methodology, the optimal predicted responses were illustrated by a coefficient of determination R2 = 0. 9839 for recovery for Fe and 0.9655 for recovery for Cu. The recovery of copper increased with the increasing dosage of Na2S and collector dosage, while the increase of pH, had a decrease in recovery of copper due to the decline in the stability of the froth, which led to the resistance to form stable bubbles for efficient recovery of copper. Selective flotation of copper and iron was achieved by varying the Na2S dosage to achieve maximum recovery. Under these flotation conditions of PAX (800 g/t), pH (8), -75 μm, sulfurizing agent (Na2S, 1000 g/t), flotation time of 8 min, pH regulator of NaOH and H 2 S O 4 and Methyl Isobutyl Carbinol (MIBC) from the experimental runs merited a grade upgrade of Cu in froth concentrate from 0.581 mass% to 0.884 mass%. An enrichment ratio of 2 was realised, with the recovery of Cu being 62%, whereas Fe in the froth concentrate increased from 69.8 mass% to 71.8 mass%. The main aim was to upgrade the grade and recovery of copper and iron to enhance the recovery for copper and iron in the next experimental stage of leaching.

Advanced 3D Electrospinning "Xspin" System: Fabrication of Bifiber Floating Oral Pharmaceutical Scaffolds for Controlled Drug Delivery

Electrospinning has become a widely used and efficient method for manufacturing nanofibers from diverse polymers. This study introduces an advanced electrospinning technique, Xspin - a multi-functional 3D printing platform coupled with electrospinning system, integrating a customised 3D printhead, MaGIC - Multi-channeled and Guided Inner Controlling printheads. The Xspin system represents a cutting-edge fusion of electrospinning and 3D printing technologies within the realm of pharmaceutical sciences and biomaterials. This innovative platform excels in the production of novel fiber with various materials and allows for the creation of highly customized fiber structures, a capability hitherto unattainable through conventional electrospinning methodologies. By integrating the benefits of electrospinning with the precision of 3D printing, the Xspin system offers enhanced control over the scaffold morphology and drug release kinetics. Herein, we fabricated a model floating pharmaceutical dosage for the dual delivery of curcumin and ritonavir and thoroughly characterized the product. Fourier transform infrared (FTIR) spectroscopy demonstrated that curcumin chemically reacted with the polymer during the Xspin process. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) confirmed the solid-state properties of the active pharmaceutical ingredient after Xspin processing. Scanning electron microscopy (SEM) revealed the surface morphology of the Xspin-produced fibers, confirming the presence of the bifiber structure. To optimize the quality and diameter control of the electrospun fibers, a design of experiment (DoE) approach based on quality by design (QbD) principles was utilized. The bifibers expanded to approximately 10-11 times their original size after freeze-drying and effectively entrapped 87% curcumin and 84% ritonavir. In vitro release studies demonstrated that the Xspin system released 35% more ritonavir than traditional pharmaceutical pills in 2 h, with curcumin showing complete release in pH 1.2 in 5 min, simulating stomach media. Furthermore, the absorption rate of curcumin was controlled by the characteristics of the linked polymer, which enables both drugs to be absorbed at the desired time. Additionally, multivariate statistical analyses (ANOVA, pareto chart, etc.) were conducted to gain better insights and understanding of the results such as discern statistical differences among the studied groups. Overall, the Xspin system shows significant potential for manufacturing nanofiber pharmaceutical dosages with precise drug release capabilities, offering new opportunities for controlled drug delivery applications.

Lipase-Assisted Synthesis of Alkyl Stearates: Optimization by Taguchi Design of Experiments and Application as Defoamers

The present work proposes the optimization of enzymatic synthesis of alkyl stearates using stearic acid, alkyl alcohols (C1-OH, C2-OH, C4-OH, C8-OH and C16-OH) and Candida rugosa lipase by a L9 (34) Taguchi-type design of experiments. Four variables were evaluated (reaction time, temperature, kU of lipase and alcohol:stearic acid molar ratio), ensuring that all variables were critical. In optimal conditions, five stearates were obtained with conversions > 90%. The obtained products were characterized by nuclear magnetic resonance (NMR). Additionally, the defoaming capacity of the five stearates was evaluated, obtaining better performance for the compound synthesized from C8-OH alcohol.

Design of Experiment for Optimizing Microencapsulation by the Solvent Evaporation Technique

We employed microemulsion combined with the solvent evaporation technique to produce biodegradable polycaprolactone (PCL) MCs, containing encapsulated isophorone diisocyanate (IPDI), to act as crosslinkers in high-performance adhesive formulations. The MC production process was optimized by applying a design of experiment (DoE) statistical approach, aimed at decreasing the MCs' average size. For that, three different factors were considered, namely the concentration of two emulsifiers, polyvinyl alcohol (PVA) and gum arabic (GA); and the oil-to-water phase ratio of the emulsion. The significance of each factor was evaluated, and a predictive model was developed. We were able to decrease the average MC size from 326 μm to 70 µm, maintaining a high encapsulation yield of approximately 60% of the MCs' weight, and a very satisfactory shelf life. The MCs' average size optimization enabled us to obtain an improved distributive and dispersive mixture of isocyanate-loaded MCs at the adhesive bond. The MCs' suitability as crosslinkers for footwear adhesives was assessed following industry standards. Peel tests revealed peel strength values above the minimum required for casual footwear, while the creep test results indicated an effective crosslinking of the adhesive. These results confirm the ability of the MCs to release IPDI during the adhesion process and act as crosslinkers for new adhesive formulations.

Optimizing the generation of mature bone marrow-derived dendritic cells in vitro: a factorial study design

BACKGROUND

Factorial design is a simple, yet elegant method to investigate the effect of multiple factors and their interaction on a specific response simultaneously. Hence, this type of study design reaches the best optimization conditions of a process. Although the interaction between the variables is widely prevalent in cell culture procedures, factorial design per se is infrequently utilized in improving cell culture output. Therefore, we aim to optimize the experimental conditions for generating mature bone marrow-derived dendritic cells (BMDCs). Two different variables were investigated, including the concentrations of the inducing factors and the starting density of the bone marrow mononuclear cells. In the current study, we utilized the design of experiments (DoE), a statistical approach, to systematically assess the impact of factors with varying levels on cell culture outcomes. Herein, we apply a two-factor, two-level (22) factorial experiment resulting in four conditions that are run in triplicate. The two variables investigated here are cytokines combinations with two levels, granulocyte-macrophage colony-stimulating factor (GM-CSF) alone or with interleukin-4 (IL4). The other parameter is cell density with two different concentrations, 2 × 106 and 4 × 106 cells/mL. Then, we measured cell viability using the trypan blue exclusion method, and a flow cytometer was used to detect the BMDCs expressing the markers FITC-CD80, CD86, CD83, and CD14. BMDC marker expression levels were calculated using arbitrary units (AU) of the mean fluorescence intensity (MFI).

RESULTS

The current study showed that the highest total viable cells and cells yield obtained were in cell group seeded at 2 × 106 cells/mL and treated with GM-CSF and IL-4. Importantly, the expression of the co-stimulatory molecules CD83 and CD80/CD86 were statistically significant for cell density of 2 × 106 cells/mL (P < 0.01, two-way ANOVA). Bone marrow mononuclear cells seeded at 4 × 106 in the presence of the cytokine mix less efficiently differentiated and matured into BMDCs. Statistical analysis via two-way ANOVA revealed an interaction between cell density and cytokine combinations.

CONCLUSION

The analysis of this study indicates a substantial interaction between cytokines combinations and cell densities on BMDC maturation. However, higher cell density is not associated with optimizing DC maturation. Notably, applying DoE in bioprocess designs increases experimental efficacy and reliability while minimizing experiments, time, and process costs.

Optimization and Validation of a Liquid Formulation for a New Recombinant Veterinary Product using QbD Approach

Protein formulation and drug characterization are one of the most difficult and time-consuming tasks because of the complexity of biotherapeutic proteins. Hence, maintaining a protein drug in its active state typically requires preventing changes in its physical and chemical properties. Quality by Design (QbD) is a systematic approach emphasizing product and process understanding. Design of Experiments (DoE) is one of the most important QbD tools, allowing the possibility to modify the formulation attributes within a defined design space. Here, we report the validation of a RP-HPLC assay for recombinant equine chorionic gonadotropin (reCG) that demonstrated a high correlation with the in vivo potency biological assay. QbD concepts were then applied to obtain an optimized liquid formulation of reCG with a predefined quality product profile. The developed strategy demonstrates the importance of applying multivariable strategies as DoE to simplify formulation stages, improving the quality of the obtained results. Moreover, it is important to highlight that this is the first time that a liquid formulation is reported for an eCG molecule, since, up to now, the only eCG products available in the market for veterinary use consisted in partially purified preparations of pregnant mare serum gonadotropin (PMSG) presented as a lyophilized product.

Design of experiments approach for the development of a validated method to determine the exenatide content in poly(lactide-co-glycolide) microspheres

Due to the lack of pharmacopeia guidelines for injectable microspheres based on poly (D, L-lactide-co-glycolide) (PLGA), an internal method validation is a critical prerequisite for quality assurance. One of the essential issues of developing peptide-based drugs loaded PLGA microspheres is the precise determination of the amount of peptide drug entrapped in the microspheres. The aim of this study is the development and optimization of a method for measuring the drug content loading of PLGA microspheres using exenatide as a model peptide drug. Exenatide-loaded PLGA microspheres were prepared by a double emulsion solvent evaporation method. The extraction method to determine exenatide content in microspheres was optimized using Design of Experiments (DoE) approach. After the initial screening of six factors, using Fractional Factorial design (FFD), four of them, including type of organic solvent, buffer/organic solvent ratio (v/v), shaking time and pH, exhibited significant effects on the response, namely the exenatide loading, and a Box-Behnken design (BBD) was subsequently applied to obtain its optimum level. The optimum level for organic solvent volume, buffer/organic solvent ratio, shaking time, and pH were 4 ml, 1, 5.6 hrs, and pH 6, respectively. The exenatide content in microspheres under these conditions was 6.4 ± 0.0 (%w/w), whereas a value of 6.1% was predicted by the derived equation. This excellent agreement between the actual and the predicted value demonstrates that the fitted model can thus be used to determine the exenatide content.

Effect of geometrical features on the capping behavior of biconvex tablets

Capping is a common industrial issue during the manufacturing of pharmaceutical tablets. It is influenced by both process and formulation parameters. In this work, a systematic study of the influence of the geometrical features of biconvex tablets on capping occurrence was performed on a model formulation, using a design of experiment. Capping was characterized by the pressure at which half of the produced tablets were capped. The influence of the tablet geometry was assessed by varying three parameters: the diameter (D), the band thickness (W) and the ratio between the radius of curvature (R) and the diameter, i.e. R/D. Results showed that having a large diameter, a low band thickness and a high curvature (i.e. a low R/D) favored capping occurrence. Moreover, the effects are not independent as cross-effect were detected. Finally, even for homothetic tablets (i.e. same R/D and W/D) it is shown that a large diameter increases capping occurrence. These results could be used in the future as a guideline for punch selection during tablet development.

Quality by Design-Optimized Glycerosome-Enabled Nanosunscreen Gel of Rutin Hydrate

Sunburn is caused by prolonged exposure to ultraviolet (UV) rays from the sun, resulting in redness of the skin as well as tenderness, swelling, and blistering issues. During the healing process, it can cause peeling, irritation, and some long-term effects, including premature aging, pigmentation, and a high risk of skin cancer. Rutin has antioxidant and anti-inflammatory effects, which could potentially reduce inflammation and soothe sunburned skin. The objective of the current proposal is to develop and create carbopol gel-encased glycerosomes for the treatment of sunburn. The Design of Expert (DoE) technique was used to optimize the proposed formulation and was subjected to various characterization parameters such as nanovesicles size, polydispersity index (PDI), surface charge, entrapment efficiency (EE), and surface morphology. The optimized rutin-loaded glycerosomes (opt-RUT-loaded-GMs) were further characterised for drug release, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, and confocal laser scanning microscopy (CLSM). The formulation showed sustained release, greater permeation into the skin, and good antioxidant activity. The dermatokinetic study of opt-RUT-loaded-GMs confirms that the Rutin hydrate had better retention in the epidermis as compared to the dermis, owing to its potential for long lasting protection after topical application. It was observed that the prepared formulation was stable, highly safe, and had good sun protection factor (SPF) values that could be used as a suitable option for topical drug administration to maximize the therapeutic efficacy of the drugs.

Development of a Carvedilol Oral Liquid Formulation for Paediatric Use

Carvedilol (CARV) is an 'off-label' β-blocker drug to treat cardiovascular diseases in children. Since CARV is nearly insoluble in water, only CARV solid forms are commercialized. Usually, CARV tablets are manipulated to prepare an extemporaneous liquid formulation for children in hospitals. We studied CARV to improve its aqueous solubility and develop an oral solution. In this study, we assessed the solubility and preliminary stability of CARV in different pH media. Using malic acid as a solubility enhancer had satisfactory results. We studied the chemical, physical, and microbiological stability of 1 mg/mL CARV-malic acid solution. A design of experiment (DoE) was used to optimize the CARV solution's preparation parameters. A 1 mg/mL CARV solution containing malic acid was stable for up to 12 months at 25 °C and 30 °C and 6 months at 40 °C. An equation associating malic acid with CARV concentrations was obtained using DoE. Microbiological data showed that the use of methylparaben was not necessary for this period of time. We successfully developed an aqueous CARV solution suitable for paediatrics and proven to be stable over a 12-month period.

Methylprednisolone 100 mg tablet formulation with pea protein: Experimental Approaches over intestinal permeability and cytotoxicity

OBJECTIVE

This study was carried out to transform the hydrolysed pea protein into a pharmaceutical tablet form by masking methylprednisolone.

SIGNIFICANCE

This study provides some crucial contributions in showing how functional excipients such as pea protein, which are generally used in food industries, can be used in pharmaceutical product formulations and their effects.

METHODS

Methylprednisolone was formulated using spray drying technology. Design Expert Software (Version 13) was used for the statistical analysis. The in vitro cytotoxic effects for NIH/3T3 mouse fibroblast cells were investigated by XTT cell viability assay. HPLC was used to analyse the Caco-2 permeability studies and dissolution tests.

RESULTS

The optimum formulation was evaluated against the reference product by performing cytotoxicity and cell permeability studies. According to our test results, Papp (apparent permeability) values of Methylprednisolone were measured around 3 x 10-6 cm/s and Fa (fraction absorbed) values around 30%.These data indicate that Methylprednisolone HCl has "moderate permeability" and our study confirmed that it could have belonged to BCS Class II-IV since both low solubility and moderate permeability.In conclusion, the findings offer valuable information to guide and inform the use of pea protein in pharmaceutical formulations.Significant effects on methylprednisolone tablet formulation designed with the philosophy of quality by design (QbD) of pea protein have been demonstrated by both in vitro and cell studies.

Microfluidics-based PLGA nanoparticles of ratiometric multidrug: From encapsulation and release rates to cytotoxicity in human lens epithelial cells

Multidrug nanomedicine is an effective therapeutic approach for the treatment of chronic diseases and cancers. However, co-encapsulation and release of drug combination at a fixed ratio by nanoparticles, particularly for long acting ocular formulations, remains challenging. Herein, poly (lactic-co-glycolic acid) nanoparticles ratiometrically co-encapsulating hydrophilic dual drugs, mitomycin C and doxorubicin, was obtained (D/M PLGANPs) by combining microfluidics and the Design of Experiments approaches. The formulation variable of lactide-to-glycolide ratios (L/G 50:50, 75:15 and 85:15) was used to achieve fast, medium and slow drug release rates of D/M PLGANPs. The dissolution of D/M PLGANPs in simulated intraocular fluid exhibited sustained release of dual drugs at the fixed ratio over 7 days, and analysis using the Korsmeyer-Peppas model showed mechanism of drug release to be governed by diffusion. More importantly, in human lens epithelial cells, the drug release rate was negatively correlated with drug potency. The slower drug release from D/M PLGANPs led to lower efficacy of drug combination against pathogenesis of cellular migration and proliferation, the key pathogenic processes of capsular opacification after cataract surgery. Compared to fast (L/G 50:50) and medium (L/G 75:15) drug release rate of D/M PLGANPs, the slow release formulation (L/G 85:15) exhibited the least cellular uptake of the dual drugs and the ratio of drug combination was not maintained intracellularly. The present study implicates the potential of using microfluidics for synthesizing polymeric nanoparticles of ratiometric drug combination and highlights the drug release rate as the critical determinant of efficacy for the long-acting nanomedicine design.

Continuous sonochemical nanotransformation of lignin - Process design and control

As the most abundant renewable aromatic polymer on the planet, lignin is gaining growing interest in replacing petroleum-based chemicals and products. However, only <5 % of industrial lignin waste is revalorized in its macromolecular form as additives, stabilizing agents or dispersant and surfactants. Herein, revalorization of this biomass was achieved by implementing an environmentally-friendly continuous sonochemical nanotransformation to obtain highly concentrated lignin nanoparticles (LigNPs) dispersions for added-value material applications. With the aim to further model and control a large-scale ultrasound-assisted lignin nanotransformation, a two-level factorial design of experiment (DoE) was implemented varying the ultrasound (US) amplitude, flow rate, and lignin concentration. Size and polydispersity measurements together with the UV-Vis spectra of lignin recorded at different time intervals of sonication allowed to monitor and understand the sonochemical process on a molecular level. The light scattering profile of sonicated lignin dispersions showed a significant particle size reduction in the first 20 min, followed by moderate particle size decrease below 700 nm until the end of the 2 h process. The response surface analysis (RSA) of the particle size data revealed that the lignin concentration and sonication time were the most important factors to achieve smaller NPs. From a mechanistic point of view, a strong impact of the particle-particle collisions due to sonication seems to be responsible for the decrease in particle size and homogenization of the particle distribution. Unexpectedly, a strong interaction between the flow rate and US amplitude on the particle size and nanotransformation efficiency was observed, yielding smaller LigNPs at high amplitude and low flow rate or vice versa. The data derived from the DoE were used to model and predict the size and polydispersity of the sonicated lignin. Furthermore, the use of the NPs spectral process trajectories calculated from the UV-Vis spectra showed similar RSA model as the dynamic light scattering (DLS) data and will potentially allow the in-line monitoring of the nanotransformation process.

Strategizing Spray Drying Process Optimization for the Manufacture of Redispersible Indomethacin Nanoparticles Using Quality-by-Design Principles

The present study adopted a Quality by Design (QbD) approach to spray dry indomethacin nanosuspension (IMC-NS) consisting of HPC-SL, poloxamer 407, and lactose monohydrate. The Box-Behnken Design was used to systematically evaluate the effects of inlet temperature, aspiration rate, and feed rate on the critical quality attributes (CQAs) [redispersibility index (RDI; minimize), % yield (maximize), and % release at 15 min (maximize)] of the indomethacin spray dried nanosuspension (IMC-SD-NS). To identify significant main and quadratic effects, two-way interactions, and create a predictive model for the spray drying process, regression analysis and ANOVA were utilized. Following optimization, the IMC-SD-NS was analyzed for its physicochemical properties using X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), and in vitro dissolution studies. Statistical analysis revealed significant independent variables, including inlet temperature, feed rate, and aspiration rate, that critically impacted the solidified end product's RDI, % yield, and % release at 15 min. The models developed for critical quality attributes (CQAs) were significant at a p-value of 0.05. The crystalline state of IMC was maintained in the solidified product, as confirmed by XRPD, and no interactions were observed between IMC and the excipients as evaluated by FTIR. In vitro dissolution studies showed improved dissolution rate for the IMC-SD-NS (3.82-fold increase in overall drug release), which may be attributed to the readily redispersible nanosized drug particles. The implementation of a well-designed study, utilizing Design of Experiments (DoE) methodology, played a crucial role in the development of a highly effective spray drying process.

Epoxide of Diosgenin Acetate Synthesis: DoE for Diastereoselective Yield Optimization, Antimicroibial, antioxidant and antiproliferative effects

Diosgenin and its derivatives have proved a huge importance in diverse biological activities. The optimized production of the diastereoisomers of the epoxide of diosgenin acetate by means of mCPBA is reported herein. This transformation had a previous design of experiments using the application of a statistical factorial DoE of 4 parameters (n^k), where one variable is varied at a time, while others stay constant. The temperature showed the greatest effect on the reaction yield; so, at 298 K the diastereomeric ratio 3:1 of α and β-epoxides, normally found, was raised to 1:1. Time was the second significant variable, but due to its high correlation with temperature, 30 minutes were required for a global 90% conversion at least. These diastereoisomers were characterized both isolated and in the mixtures obtained, to determine their antioxidant, antimicrobial and antiproliferative activity, finding a low antioxidant capacity by DPPH, but antimicrobial activity at the level of penicillin in gram negative bacteria by 1β better to 1α. The antiproliferative capacity was higher for diastereoisomer β, agreeing with the proportion of the mixture obtained by different conditions, increasing this in relation to the amount of this diastereoisomer present in hormone-dependent cancer cell lines such as Hela, PC-3 and MCF-7, with 10.0 µM obtained values of viability at 21.8 %, 35.8 % and 12.3 % respectively. DoE optimization allows to manipulate the ratio between diastereoisomers with the minimum number of experiments, extending the analysis of the effect of the ratio between diastereoisomers and the in silico potential as well as the biological activity.

Development of Biopredictive Dissolution Method for Extended-Release Desvenlafaxine Tablets

This study aimed to develop a biopredictive dissolution method for desvenlafaxine ER tablets using design of experiments (DoE) and physiologically based biopharmaceutics modeling (PBBM) to address the challenge of developing generic drug products by reducing the risk of product failure in pivotal bioequivalence studies. For this purpose, a PBBM was developed in GastroPlus^® and combined with a Taguchi L9 design, to evaluate the impact of different drug products (Reference, Generic #1 and Generic #2) and dissolution test conditions on desvenlafaxine release. The influence of the superficial area/volume ratio (SA/V) of the tablets was observed, mainly for Generic #1, which presented higher SA/V than the others, and a high amount of drug dissolved under similar test conditions. The dissolution test conditions of 900 mL of 0.9% NaCl and paddle at 50 rpm with sinker showed to be biopredictive, as it was possible to demonstrate virtual bioequivalence for all products, despite their release-pattern differences, including Generic #3 as an external validation. This approach led to a rational development of a biopredictive dissolution method for desvenlafaxine ER tablets, providing knowledge that may help the process of drug product and dissolution method development.

Extraction of Isoflavones, Alpha-Hydroxy Acids, and Allantoin from Soybean Leaves-Optimization by a Mixture Design of the Experimental Method

Soybeans are commonly known as a valuable source of biologically active compounds including isoflavones as well as allantoin and alpha-hydroxy acids. Since these compounds exhibit skin therapeutic effects, they are widely used in the cosmetic and pharmaceutical industries. The presented paper shows the optimization of three solvent systems (ethanol, water, and 1,3-propanediol) to increase the extraction efficiency of isoflavones (daidzin, genistin, 6″-O-malonyldaidzin, 6″-O-malonylglycitin, 6″-O-malonylgenistin), allantoin, and alpha-hydroxy acids (citric acid, malic acid) from soybean leaves. A simplex centroid mixture design for three solvents with interior points was applied for the experimental plan creation. Based on the obtained results of metabolite extraction yield in relation to solvent composition, polynomial regression models were developed. All models were significant, with predicted R-squared values between 0.77 and 0.99, while in all cases the model's lack of fit was not significant. The optimal mixture composition enabling the maximization of extraction efficiency was as follows: 32.9% ethanol, 53.9% water, and 13.3% propanediol (v/v/v). Such a mixture composition provided the extraction of 99%, 91%, 100%, 92%, 99%, 70%, 92%, and 69% of daidzin, genistin, 6″-O-malonyldaidzin, 6″-O-malonylglycitin, 6″-O-malonylgenistin, allantoin, citric acid, and malic acid, respectively. The solvent mixture composition developed provides a good extraction efficiency of the metabolites from soybean leaves and high antioxidant properties.

Response surface methodology combined Box-Behnken design optimized green kinetic spectrophotometric and HPLC methods to quantify angiotensin receptor blocker valsartan in pharmaceutical formulations

The high-performance liquid chromatographic (HPLC) and kinetic spectrophotometric methods were established to compute valsartan (VAL) in pharmaceutical formulations. The spectrophotometric procedures adopted initial rate, fixed time, and equilibrium strategies to assess VAL. The method was based on the carboxylic acid group of the oxidized VAL with a mixture of potassium iodate (KIO₃) and potassium iodide (KI) at room temperature, producing a stable, yellow-coloured absorb at 352 nm. The critical parameters were optimized using green process optimization methodology such as Box-Behnken design (BBD) which belongs to response surface methodology (RSM). After the screening, experiments identified them as significant, and then three crucial factors were optimised: KI volume, KIO₃ volume, and reaction time against response as absorbance. The HPLC procedure was also optimized based on the desirability function on RSM-BBD. The parameters such as pH, methanol (%), and flow rate (ml/min) were optimized with the best responses: peak area, symmetry, and theoretical plates. The linearity of spectrophotometric and HPLC methods was within the range of 2-24 and 0.25-11.25 µg/ml, respectively. The developed procedures produced excellent accuracy and precision. The design of the experiment (DoE) setting explained and discussed the individual steps and the importance of independent and dependent variables used to develop the model and optimization. The method was validated as per the International Conference on Harmonization (ICH) guidelines. Furthermore, Youden's robustness study was applied with factorial combinations of the preferred analytical parameters and explored their influence with alternative conditions. The analytical Eco-Scale score was calculated and was found a better option as green methods to quantify VAL. The results were reproducible with the analysis completed with biological fluid and wastewater samples.

Anti-microbial lead compound Sulfonamide - Anthranilate derivative Methyl-Ester-Toluene-Sulfonamide and its purity by Liquid Chromatography to develop the New Drug Application

The newly innovated and synthesized lead molecule Methyl-Ester-Toluene-Sulfonamide is the combined derivative of sulphonamide-anthranilate. The estimation was achieved by gradient elution using mobile phase 0.1% Triethylamine in water and with pH 2.0 as mobile phase A and mixture of acetonitrile and tetrahydrofuran in the ratio of (975:25) v/v as mobile phase B at 0.8 mL min^-1 flow rate and 210 nm wavelength on Agilent 1260 infinity series HPLC system equipped with DAD detector. The column used was ACE 3 C18 PFP (250 mm × 4.6 mm) 3 μm column operating at 40 °C temperature. The gradient programme is time (min)/% B: 0.0/50, 3.0/50, 15.0/70, 25.0/90, 30.0/90, 31/50, & 38/50. The method is simple, accurate, rapid and selective. The method was found linear with concentration range of 1.6 to 240 μg/mL. The accuracy data obtained from 98.5 % to 100.5 %. The method validation data and QbD-based robustness study results indicate that the developed method is robust and fit for routine use in the quality control laboratory. Therefore, the ready availability of method can be useful in pharmaceutical new drug development.

Analysis of Influencing Parameters Enhancing the Plucking Efficiency of Piezoelectric Energy Harvesters

The integration of energy harvesting systems into sensing technologies can result in novel autonomous sensor nodes, characterized by significant simplification and mass reduction. The use of piezoelectric energy harvesters (PEHs), particularly in cantilever form, is considered as one of the most promising approaches aimed at collecting ubiquitous low-level kinetic energy. Due to the random nature of most excitation environments, the narrow PEH operating frequency bandwidth implies, however, the need to introduce frequency up-conversion mechanisms, able to convert random excitation into the oscillation of the cantilever at its eigenfrequency. A first systematic study is performed in this work to investigate the effects of 3D-printed plectrum designs on the specific power outputs obtainable from FUC excited PEHs. Therefore, novel rotating plectra configurations with different design parameters, determined by using a design-of-experiment methodology and manufactured via fused deposition modeling, are used in an innovative experimental setup to pluck a rectangular PEH at different velocities. The obtained voltage outputs are analyzed via advanced numerical methods. A comprehensive insight into the effects of plectrum properties on the responses of the PEHs is attained, representing a new and important step towards the development of efficient harvesters aimed at a wide range of applications, from wearable devices to structural health monitoring systems.

A combined qualitative and quantitative method development and validation of vancomycin hydrochloride injection formulation by HPLC and UV involving quality by design

A selective, specific, precise, linear, accurate and robust analytical method was developed and validated for the assay of vancomycin HCl in vancomycin hydrochloride injection. Comparative UV spectrophotometric and reverse-phase HPLC were used to develop the quantitative determination. Acetonitrile and pH 2.2 phosphate buffer in the ratio 20:80 v/v were used as the mobile phase, and a flow rate of 1.0 ml/min with a 20 min run time. The detection was carried out at 235 nm with a Nucleosil C₁₈ (250 × 4.6 mm) 10 μm column, and the ambient column temperature was maintained. The method uses a 20 μl injection volume and diluent as a blank solution in this connection. The method was validated as per the current regulatory guidelines. The linearity of this method was found to be linear in the range of 50-150% of the working concentration, and the correlation coefficient was >0.999. The method's accuracy was within the acceptable range, which was 98.1-101.5%. The method's precision was within an acceptable range of about 0.32% RSD. The analytical solution was stable for up to 48 h at room temperature. The method's robustness was proved by utilizing quality design tools. Stress studies demonstrated the method's stability-indicating nature.

Hybrid volatilomics in cancer diagnosis by HS-GC-FID fingerprinting

Assessing volatile organic compounds (VOCs) as cancer signatures is one of the most promising techniques toward developing non-invasive, simple, and affordable diagnosis. Here, we have evaluated the feasibility of employing static headspace extraction (HS) followed by gas chromatography with flame ionization detector (GC-FID) as a screening tool to discriminate between cancer patients (head and neck-HNC,n= 15; and gastrointestinal cancer-GIC,n= 19) and healthy controls (n= 37) on the basis of a non-target (fingerprinting) analysis of oral fluid and urine. We evaluated the discrimination considering a single bodily fluid and adopting the hybrid approach, in which the oral fluid and urinary VOCs profiles were combined through data fusion. We used supervised orthogonal partial least squares discriminant analysis for classification, and we assessed the prediction power of the models by analyzing the values of goodness of prediction (Q²Y), area under the curve (AUC), sensitivity, and specificity. The individual models HNC urine, HNC oral fluid, and GIC oral fluid successfully discriminated between healthy controls and positive samples (Q²Y = 0.560, 0.525, and 0.559; AUC = 0.814, 0.850, and 0.926; sensitivity = 84.8, 70.2, and 78.6%; and specificity = 82.3; 81.5; 87.5%, respectively), whereas GIC urine was not adequate (Q²Y = 0.292, AUC = 0.694, sensitivity = 66.1%, and specificity = 77.0%). Compared to the respective individual models, Q²Y for the hybrid models increased (0.623 for hybrid HNC and 0.562 for hybrid GIC). However, sensitivity was higher for HNC urine and GIC oral fluid than for hybrid HNC (75.6%) and hybrid GIC (69.8%), respectively. These results suggested that HS-GC-FID fingerprinting is suitable and holds great potential for cancer screening. Additionally, the hybrid approach tends to increase the predictive power if the individual models present suitable quality parameter values. Otherwise, it is more advantageous to use a single body fluid for analysis.

Employing QbD strategies to assess the impact of cell viability and density on the primary recovery of monoclonal antibodies

Quality by Design (QbD) is one of the most important tools for the implementation of Process Analytical Technology (PAT) in biopharmaceutical production. For optimal characterization of a monoclonal antibody (mAb) upstream process a stepwise approach was implemented. The upstream was divided into three process stages, namely inoculum expansion, production, and primary recovery, which were investigated individually. This approach enables analysis of process parameters and associated intermediate quality attributes as well as systematic knowledge transfer to subsequent process steps. Following previous research, this study focuses on the primary recovery of the mAb and thereby marks the final step toward a holistic characterization of the upstream process. Based on gained knowledge during the production process evaluation, the cell viability and density were determined as critical parameters for the primary recovery. Directed cell viability adjustment was achieved using cytotoxic camptothecin in a novel protocol. Additionally, the cell separation method was added to the Design of Experiments (DoE) as a qualitative factor and varied between filtration and centrifugation. To assess the quality attributes after cell separation, the bioactivity of the mAb was analyzed using a cell-based assay and the purity of the supernatant was evaluated by measurement of process related impurities (host cell protein proportion, residual DNA). Multivariate data analysis of the compiled data confirmed the hypothesis that the upstream process has no significant influence on the bioactivity of the mAb. Therefore, process control must be tuned towards high mAb titers and purity after the primary recovery, enabling optimal downstream processing of the product. To minimize amounts of host cell proteins and residual DNA the cell viability should be maintained above 85% and the cell density should be controlled around 15 × 10⁶ cells/ml during the cell removal. Thereby, this study shows the importance of QbD for the characterization of the primary recovery of mAbs and highlights the useful implementation of the stepwise approach over subsequent process stages.

Improved Itaconate Production with Ustilago cynodontis via Co-Metabolism of CO2-Derived Formate

In recent years, it was shown that itaconic acid can be produced from glucose with Ustilago strains at up to maximum theoretical yield. The use of acetate and formate as co-feedstocks can boost the efficiency of itaconate production with Ustilaginaceae wild-type strains by reducing the glucose amount and thus the agricultural land required for the biotechnological production of this chemical. Metabolically engineered strains (U. cynodontis Δfuz7 Δcyp3 ↑P_ria1 and U. cynodontis Δfuz7 Δcyp3 P_etefmttA ↑P_ria1) were applied in itaconate production, obtaining a titer of 56.1 g L^-1 and a yield of 0.55 g_itaconate per g_substrate. Both improved titer and yield (increase of 5.2 g L^-1 and 0.04 g_itaconate per g_substrate, respectively) were achieved when using sodium formate as an auxiliary substrate. By applying the design-of-experiments (DoE) methodology, cultivation parameters (glucose, sodium formate and ammonium chloride concentrations) were optimized, resulting in two empirical models predicting itaconate titer and yield for U. cynodontis Δfuz7 Δcyp3 P_etefmttA ↑P_ria1. Thereby, an almost doubled itaconate titer of 138 g L^-1 was obtained and a yield of 0.62 g_itaconate per g_substrate was reached during confirmation experiments corresponding to 86% of the theoretical maximum. In order to close the carbon cycle by production of the co-feed via a "power-to-X" route, the biphasic Ru-catalysed hydrogenation of CO₂ to formate could be integrated into the bioprocess directly using the obtained aqueous solution of formates as co-feedstock without any purification steps, demonstrating the (bio)compatibility of the two processes.

Rational Design of a Polyurethane Foam

Polyurethane (PU) foams are exceptionally versatile due to the nature of PU bond formation and the large variety of polymeric backbones and formulation components such as catalysts and surfactants. This versatility introduces a challenge, namely a near unlimited number of variables for formulating foams. In addition to this, PU foam development requires expert knowledge, not only in polyurethane chemistry but also in the art of evaluating the resulting foams. In this work, we demonstrate that a rational experimental design framework in conjunction with a design of experiments (DoE) approach reduces both the number of experiments required to understand the formulation space and reduces the need for tacit knowledge from a PU expert. We focus on an in-depth example where a catalyst and two surfactants of a known formulation are set as factors and foam physical properties are set as responses. An iterative DoE approach is used to generate a set of foams with substantially different cell morphology and hydrodynamic behaviour. We demonstrate that with 23 screening formulations and 16 final formulations, foam physical properties can be modelled from catalyst and surfactant loadings. This approach also allows for the exploration of relationships between the cell morphology of PU foam and its hydrodynamic behaviour.

based on analytical quality by design (AQbD) concept

INTRODUCTION

Medical uses of Cannabis sativa L. have gained interest in recent decades, which highlights the need for defining appropriate quality specifications for Cannabis-based products. However, the complexity of plant matrices and structural similarity between cannabinoids make analytical development a challenging task. Thus, the application of analytical quality by design (AQbD)-driven approaches can favour the development of fit-for-purpose methods.

OBJECTIVES

To develop a high-performance liquid chromatography diode array detector (HPLC-DAD) method for simultaneous quantification of cannabidiol, Δ⁹ -tetrahydrocannabinol, cannabidiolic acid, tetrahydrocannabinolic acid, and cannabinol in C. sativa by applying an AQbD-driven approach.

MATERIALS AND METHODS

Critical method attributes (CMA) were established following the analytical target profile. Critical method variables (CMV) were categorised based on risk assessment and literature review. Selected CMV regarding sample preparation and chromatographic conditions were optimised using response surface methodology (RSM). The working point was estimated by multiple response optimisation using Deringer's desirability function. The validity of the optimal conditions was confirmed experimentally. Method validation was performed according to ANVISA and ICH guidelines. Relative response factors (RRFs) were also determined.

RESULTS AND DISCUSSION

Baseline resolution of 12 major cannabinoids was achieved in a 35 min chromatographic analysis. All experimental responses obtained during confirmatory analyses were within the prediction intervals (PI_95% ). Method's selectivity, linearity (10-100 μg/mL), precision, bias, extraction recovery, and ruggedness were satisfactorily demonstrated.

CONCLUSIONS

The application of an AQbD-driven approach allowed for a better understanding of the effects of the ensemble of CMV on the analyte's behaviour, enabling the definition of appropriate conditions to ensure consistent achievement of the intended method's performance.

Quality Definition in Micro Injection Molding Process by Means of Surface Characterization Parameters

Quality evaluation of micro injection molded products is a complex task, in particular when instruments basing on contact methods are used and issues in measurements could arise due to the contact tool dimension not fitting well with extremely narrow features. Therefore, in these cases, optical methods may be preferred for the evaluation of molded products’ dimensions and surface quality, especially for parts devoted to applications requiring functional purposes. In this context, the present paper proposes the use of surface parameters as a quality index for the evaluation of both the micro injection molding process and the resulting products. To this aim, two experimental procedures were implemented to allow for: (i) the evaluation of the most suitable surface parameters identified in relation to the process parameters; (ii) comparisons of the surface parameters findings with those obtained by classic dimensional quantity via a designed experimental plan (DoE). The results show that the surface parameters, evaluated in critical areas of the components, can ensure reliable estimates for the surface quality of the molded parts and can be preferred in comparison to linear measurements.

Maximizing the recovery of the native p28 bacterial peptide with improved activity and maintained solubility and stability in Escherichia coli BL21 (DE3)

p28 is a natural bacterial product, which recently has attracted much attention as an efficient cell penetrating peptide (CPP) and a promising anticancer agent. Considering the interesting biological qualities of p28, maximizing its expression appears to be a prominent priority. The optimization of such bioprocesses might be facilitated by utilizing statistical approaches such as Design of Experiment (DoE). In this study, we aimed to maximize the expression of "biologically active" p28 in Escherichia coli BL21 (DE3) host by harnessing statistical tools and experimental methods. Using Minitab, Plackett-Burman and Box-Behnken Response Surface Methodology (RSM) designs were generated to optimize the conditions for the expression of p28. Each condition was experimentally investigated by assessing the biological activity of the purified p28 in the MCF-7 breast cancer cell line. Seven independent variables were investigated, and three of them including ethanol concentration, OD₆₀₀ of the culture at the time of induction, and the post-induction temperature were demonstrated to significantly affect the p28 expression in E. coli. The cytotoxicity, penetration efficiency, and total process time were measured as dependent variables. The optimized expression conditions were validated experimentally, and the final products were investigated in terms of expression yield, solubility, and stability in vitro. Following the optimization, an 8-fold increase of the concentration of p28 expression was observed. In this study, we suggest an optimized combination of effective factors to produce soluble p28 in the E. coli host, a protocol that results in the production of a significantly high amount of the biologically active peptide with retained solubility and stability.

Enhanced stability and oral bioavailability of erlotinib by solid self nano emulsifying drug delivery systems

The present investigation demonstrates the preparation of solid self nanoemulsfying drug delivery system (sSNEDDS) to enhance stability and bioavailability of Erlotinib (ERL) via the oral route. Capmul®MCM EP (CPM EP, oil), Cremophor® RH 40 (CMR RH 40, surfactant), and LBF CS (LBF CS, cosurfactant) were chosen as chief components for preparing Liquids SNEDDS (L-ERL-SNEDDS) based on solubility and emulsion forming ability. Pseudo ternary phase diagram and constrained mixture designs were applied to identify the self-emulsifying area and it was found that CPM EP, CMR RH 40, and LBF CS in the ratio of 59:11:30 showed optimized particle size (110.08 nm), with narrow PDI (0.114) and high ERL loading capacity (14.31 mg/g). Adsorption method was implemented for solidification of L-ERL-SNEDDS. Among various solid carriers were studied, Aerosil® 200 (A200) was finalized based on free flowing property and reconstitution ability. DSC and XRD studies revealed that crystallinity of drug was reduced in developed system. The developed formulation (named as, A200-ERL-sSNEDDS) showed increased cytotoxicity and apoptosis in PANC-1 and MIA PaCa-2 cells. Pharmacokinetic studies revealed ∼2.2 times increase in AUC0-∞values in case of A200-ERL-sSNEDDS as compared to free ERL. Thus current strategy can be extrapolated for delivering of poorly soluble drugs via oral route.

Optimized Ultrasound-Assisted Enzymatic Extraction of Phenolic Compounds from Rosa canina L. Pseudo-Fruits (Rosehip) and Their Biological Activity

Two techniques, namely, optimized ultrasound-assisted extraction (UAE) and enzyme-assisted extraction (EAE), were used to promote the extraction of phenolic compounds from the pseudo-fruits of Rosa canina L. (RC). For UAE, an optimization process based on the design of experiment (DoE) principles was used for determining the dependence between three variables (i.e., time of extraction, ultrasound amplitude, and the material-to-water ratio) and the total phenolic content of the samples. For EAE, a 2:1:1 pectinase, cellulase, and hemicellulase enzymatic blend was used as pre-treatment for optimized UAE, inducing a higher total phenolic content. The untargeted phenolic profiling approach revealed a great abundance of lower molecular weight phenolics (1.64 mg Eq./g) in UAE-RC extracts, whilst gallic acid (belonging to hydroxybenzoic acid derivatives) was the most abundant individual compound of both extracts. The unsupervised multivariate statistics clearly discriminated the impact of enzymatic pre-treatment on the phenolic profile of RC pseudo-fruits. Finally, Pearson’s correlation coefficients showed that anthocyanins, phenolic acids, and tyrosol derivatives were those compounds mostly correlated to the in vitro antioxidant potential of the extracts, whilst negative and significant (p < 0.05) correlation coefficients were recorded when considering the enzymatic inhibition activities. The highest enzyme-inhibitory activity has been identified against α-glucosidase, which indicates an antidiabetic effect.

Orally delivered solid lipid nanoparticles of irinotecan coupled with chitosan surface modification to treat colon cancer: Preparation, in-vitro and in-vivo evaluations

Irinotecan-loaded solid lipid nanoparticles (IRI-SLNs) was formulated and tested for its potential activity against colon cancer. IRI-SLNs were prepared by applying the principles of DoE. Nanoparticles were further surface modified using chitosan. Characterizations such as size, poly-dispersity, surface charge, morphology, entrapment, drug release pattern, cytotoxicity were conducted. In-vivo studies in male Wistar rats were carried to ascertain distribution pattern of SLNs and their acute toxicity on various vital organs. Lastly, stability of the SLNs were evaluated. Particles had a size, polydispersity and zeta potential of 430.77 ± 8.69 nm, 0.36 ± 0.02 and -40.06 ± 0.61 mV, respectively. Entrapment of IRI was 62.24 ± 2.90% in IRI-SLNs. Sustained drug release was achieved at a colonic pH and long-term stability of NPs was seen. Cytotoxicity assay results showed that SLNs exhibited toxicity on HCT-116 cells. Biodistribution studies confirmed higher concentration of drug in the colon after surface modification. An acute toxicity study conducted for 7 days showed no severe toxic effects on major organs. Thus, we picture that the developed SLNs may benefit in delivering IRI to the tumour cells, therefore decreasing the dose and dose-associated toxicities.

Modeling Experimental Parameters for the Fabrication of Multifunctional Surfaces Composed of Electrospun PCL/ZnO-NPs Nanofibers

In this work, a one-step electrospinning technique has been implemented for the design and development of functional surfaces with a desired morphology in terms of wettability and corrosion resistance by using polycaprolactone (PCL) and zinc oxide nanoparticles (ZnO NPs). The surface morphology has been characterized by confocal microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle (WCA), whereas the corrosion resistance has been evaluated by Tafel polarization curves. Strict control over the input operational parameters (applied voltage, feeding rate, distance tip to collector), PCL solution concentration and amount of ZnO NPs have been analyzed in depth by showing their key role in the final surface properties. With this goal in mind, a design of experiment (DoE) has been performed in order to evaluate the optimal coating morphology in terms of fiber diameter, surface roughness (Ra), water contact angle (WCA) and corrosion rate. It has been demonstrated that the solution concentration has a significant effect on the resultant electrospun structure obtained on the collector with the formation of beaded fibers with a higher WCA value in comparison with uniform bead-free fibers (dry polymer deposition or fiber-merging aspect). In addition, the presence of ZnO NPs distributed within the electrospun fibers also plays a key role in corrosion resistance, although it also leads to a decrease in the WCA. Finally, this is the first time that an exhaustive analysis by using DoE has been evaluated for PCL/ZnO electrospun fibers with the aim to optimize the surface morphology with the better performance in terms of corrosion resistance and wettability.

Extrusion and Injection Molding of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate) (PHBHHx): Influence of Processing Conditions on Mechanical Properties and Microstructure

Biobased and biodegradable polyhydroxyalkanoates (PHAs) have great potential as sustainable packaging materials. However, improvements in their processing and mechanical properties are necessary. In this work, the influence of melt processing conditions on the mechanical properties and microstructure of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is examined using a full factorial design of experiments (DoE) approach. We have found that strict control over processing temperature, mold temperature, screw speed, and cooling time leads to highly increased elongation at break values, mainly under influence of higher mold temperatures at 80 °C. Increased elongation of the moldings is attributed to relaxation and decreased orientation of the polymer chains together with a homogeneous microstructure at slower cooling rates. Based on the statistically substantiated models to determine the optimal processing conditions and their effects on microstructure variation and mechanical properties of PHBHHx samples, we conclude that optimizing the processing of this biopolymer can improve the applicability of the material and extend its scope in the realm of flexible packaging applications.

Integrated Process Model Applications Linking Bioprocess Development to Quality by Design Milestones

Maximizing the value of each available data point in bioprocess development is essential in order to reduce the time-to-market, lower the number of expensive wet-lab experiments, and maximize process understanding. Advanced in silico methods are increasingly being investigated to accomplish these goals. Within this contribution, we propose a novel integrated process model procedure to maximize the use of development data to optimize the Stage 1 process validation work flow. We generate an integrated process model based on available data and apply two innovative Monte Carlo simulation-based parameter sensitivity analysis linearization techniques to automate two quality by design activities: determining risk assessment severity rankings and establishing preliminary control strategies for critical process parameters. These procedures are assessed in a case study for proof of concept on a candidate monoclonal antibody bioprocess after process development, but prior to process characterization. The evaluation was successful in returning results that were used to support Stage I process validation milestones and demonstrated the potential to reduce the investigated parameters by up to 24% in process characterization, while simultaneously setting up a strategy for iterative updates of risk assessments and process controls throughout the process life-cycle to ensure a robust and efficient drug supply.

Experimental Characterization of Optimized Piezoelectric Energy Harvesters for Wearable Sensor Networks

The development of wearable devices and remote sensor networks progressively relies on their increased power autonomy, which can be further expanded by replacing conventional power sources, characterized by limited lifetimes, with energy harvesting systems. Due to its pervasiveness, kinetic energy is considered as one of the most promising energy forms, especially when combined with the simple and scalable piezoelectric approach. The integration of piezoelectric energy harvesters, generally in the form of bimorph cantilevers, with wearable and remote sensors, highlighted a drawback of such a configuration, i.e., their narrow operating bandwidth. In order to overcome this disadvantage while maximizing power outputs, optimized cantilever geometries, developed using the design of experiments approach, are analysed and combined in this work with frequency up-conversion excitation that allows converting random kinetic ambient motion into a periodical excitation of the harvester. The developed optimised designs, all with the same harvesters’ footprint area of 23 × 15 mm, are thoroughly analysed via coupled harmonic and transient numerical analyses, along with the mostly neglected strength analyses. The models are validated experimentally via innovative experimental setups. The thus-proposed ϕ = 50 mm watch-like prototype allows, by using a rotating flywheel, the collection of low-frequency (ca. 1 to 3 Hz) human kinetic energy, and the periodic excitation of the optimized harvesters that, oscillating at their eigenfrequencies (~325 to ~930 Hz), display specific power outputs improved by up to 5.5 times, when compared to a conventional rectangular form, with maximal power outputs of up to >130 mW and average power outputs of up to >3 mW. These power levels should amply satisfy the requirements of factual wearable medical systems, while providing also an adaptability to accommodate several diverse sensors. All of this creates the preconditions for the development of novel autonomous wearable devices aimed not only at sensor networks for remote patient monitoring and telemedicine, but, potentially, also for IoT and structural health monitoring.

A Design of Experiment Approach to Optimize Spray-Dried Powders Containing Pseudomonas aeruginosaPodoviridae and Myoviridae Bacteriophages

In the present study, we evaluated the effect of spray-drying formulations and operating parameters of a laboratory-scale spray-dryer on the characteristics of spray-dried powders containing two Pseudomonas aeruginosa bacteriophages exhibiting different morphotypes: a podovirus (LUZ19) and a myovirus (14-1). We optimized the production process for bacteriophage-loaded powders, with an emphasis on long-term storage under ICH (international conference on harmonization) conditions. D-trehalose-/L-isoleucine-containing bacteriophage mixtures were spray-dried from aqueous solutions using a Büchi Mini Spray-dryer B-290 (Flawil, Switzerland). A response surface methodology was used for the optimization of the spray-drying process, with the following as-evaluated parameters: Inlet temperature, spray gas flow rate, and the D-trehalose/L-isoleucine ratio. The dried powders were characterized in terms of yield, residual moisture content, and bacteriophage lytic activity. L-isoleucine has demonstrated a positive impact on the activity of LUZ19, but a negative impact on 14-1. We observed a negligible impact of the inlet temperature and a positive correlation of the spray gas flow rate with bacteriophage activity. After optimization, we were able to obtain dry powder preparations of both bacteriophages, which were stable for a minimum of one year under different ICH storage conditions (up to and including 40 °C and 75% relative humidity).

QbD enabled optimization of solvent shifting method for fabrication of PLGA-based nanoparticles for promising delivery of Capecitabine for antitumor activity

The key objective of the current research was to fabricate and optimize Capecitabine (Cap)-loaded [poly(lactic-co-glycolic acid)] PLGA-based nanoparticles (NPs) by enabling quality by design (QbD) approach for enhancing antitumor activity by promising delivery of the drug at the colonic site. The current research was based on fabricating PLGA-based nanoparticles along with Eudragit S100 as enteric polymer employing solvent shifting method followed by optimization using QbD approach. This approach was found to be useful for understanding the multiple factors and their interaction influencing the product by utilizing Design of Experiment (DOE). Box-Behnken design (BBD) was adopted to achieve the required critical quality attributes (CQAs), i.e., minimizing particle size, maximizing entrapment efficiency, and minimizing PDI value. The optimized nanoparticles were lyophilized and characterized by FT-IR, DSC, TEM, DLS, MTT assay using HT-29 cell lines, and in vivo pharmacokinetic studies. The optimized PLGA-based nanoparticles were found to possess average particle size, PDI, zeta potential, and entrapment efficiency of 195 nm, 0.214, -6.65 mV, and 65%, respectively. TEM analysis revealed the spherical nature of nanoparticles. The FT-IR and DSC studies revealed no interaction. The bioavailability of Cap-loaded nanoparticles was found to be two fold increased than the pure drug, and also, it exhibited significantly more cytotoxic to tumor cells as compared to pure drug as confirmed by MTT assay. The optimized PLGA-based nanoparticles found to possess enhanced bioavailability and significantly more cytotoxic potential as compared to pure drug.

Fractional Factorial Designs: An Underutilized Tool for Rapid In Vitro System Development

Anther and microspore culture for producing haploid plants are very complex systems and include general effects where the specific effects must be identified and optimized to develop culture systems capable of producing the large numbers of haploids required by breeding programs. These general effects include genotype, physiological state of the source plant, age of the anthers and microspores, preculture treatments, culture conditions, and culture media. Design of experiments (DoE) is an experimental approach specifically designed to identify and optimize the multiple factors that make up complex systems, and is ideally suited for developing in vitro systems to produce haploids. The basic DoE strategy starts by screening multiple factors thought to affect the responses being measured. Screening identifies factors with large and small effects. Factors with large effects are used to manipulate the system, and are moved to the DoE optimization phase such as response surface methodology. Factors with small or trivial effects are eliminated from further consideration, and this simplifies the system. The basic concepts of fractional factorial designs and how to use them are explained. Fractional factorials are the most important DoE screening tool and are the first experiments run before DoE optimization experiments. To illustrate the unique properties of fractional factorials, a detailed example is provided that includes all of the calculations so that no statistical software is required.

The Potential of Macroporous Silica-Nanocrystalline Cellulose Combination for Formulating Dry Emulsion Systems with Improved Flow Properties: A DoE Study

The objective of this study was to explore the possible use of a new combination of two excipients, i.e., nanocrystalline cellulose (NCC) and macroporous silica (MS), as matrix materials for the compounding of dry emulsion systems and the effects these two excipients have on the characteristics of dry emulsion powders produced by the spray drying process. A previously developed liquid O/W nanoemulsion, comprised of simvastatin, 1-oleoyl-rac-glycerol, Miglyol 812 and Tween 20, was employed. In order to comprehend the effects that these two matrix formers have on the spray drying process and on dry emulsion powder characteristics, alone and in combination, a DoE (Design of Experiment) approach was used. The physicochemical properties of dry emulsion samples were characterised by atomic force microscopy, scanning electron microscopy, mercury intrusion porosimetry, energy-dispersive X-ray spectroscopy and laser diffraction analysis. Additionally, total release and dissolution experiments were performed to assess drug release from multiple formulations. It was found that the macroporous silica matrix drastically improved flow properties of dry emulsion powders; however, it partially trapped the oil—drug mixture inside the pores and hindered complete release. NCC showed its potential to reduce oil entrapment in MS, but because of its rod-shaped particles deposited on the MS surface, powder flowability was deteriorated.

Background, Applications and Issues of the Experimental Designs for Mixture in the Food Sector

BACKGROUND

Mixtures play a key role in Food Science and Technology. For studying them, rational approaches should be used. In detail, the experimental designs for mixtures are useful tools for studying the effects of ingredients/components in formulations.

RESULTS

Food Science and Technology is the fourth category among the total records considered in this review. The applications span from food formulation to the composition of modified atmosphere, shelf-life improvement and bioactives extraction. However, the majority of the studies regards few products and ingredients. Simplex-lattice and simplex-centroid designs are the most common used, although some optimal designs, such as the D-optimal, have also interesting applications. Finally, some issues are highlighted, which basically regard the interpretation of the models coefficients and the lack of model validation.

CONCLUSION

In the last decade, mixture designs have been fairly used in the field of Food Science and Technology. Modeling the response(s) allows researchers to achieve a global knowledge of the system under study within the defined experimental domain. However, the majority of application has regarded limited classes of products, and thus an increase in the spectrum of applications is desired.

HPLC-MS-based design of experiments approach on cocoa roasting

Modern statistical methods, such as the design of experiments and response surface methodology, are widely used to describe changes in multiparameter processes during the processing of food in both science and technology contexts. However, these approaches are described to a lesser degree in the case of cocoa roasting than other foods and processes. Our study aimed to use the design of experiments to establish a model of cocoa roasting for relevant flavor-related constituents. We have used HPLC-MS techniques to link standard process parameters with chemical compounds changing in concentration during cocoa roasting. Influence of time, temperature, the addition of water, acid, and base, on relative concentrations of procyanidin monomers, dimers, and trimers, an Amadori compound, and a peptide, was shown. High-quality models for each compound were established and validated, displaying good prediction accuracy. Such an approach could be used to optimize processing conditions for cocoa roasting in order to influence the concentration of certain chemical compounds, and in turn, improving the flavor of chocolate products.

A multivariate approach to investigate the NMR CPMG pulse sequence for analysing low MW species in polymers

Detection and quantification of low molecular weight components in polymeric samples via nuclear magnetic resonance (NMR) spectroscopy can be difficult due to overlapping signal caused by line broadening characteristics of polymers. A way of overcoming this problem could be the exploitation of the difference in relaxation between small molecules and macromolecular species, such as the application of a T₂ filter by using the Carr-Purcell-Meiboom-Gill (CPMG) spin-echo pulse sequence. This technique, largely exploited in metabolomics studies, is applied here to material sciences. A Design of Experiments approach was used for evaluating the effect of different acquisition parameters (relaxation delay, echo time and number of cycles) and sample-related ones (concentration and polymer molecular weight) on selected responses, with a particular interest in performing a reliable quantitative analysis. Polymeric samples containing small molecules were analysed by NMR with and without the application of the filter, and analysis of variance was used to identify the most influential parameters. Results indicated that increasing the polymer concentration, hence sample viscosity, further attenuates polymer signals in CPMG experiments because the T₂ of those signals tends to decrease with increasing viscosity. The signal-to-noise ratio measured for small molecules can undergo a minimum loss when specific parameters are chosen in relation to the polymer molecular weight. Furthermore, the difference in dynamics between aliphatic and aromatic nuclei, as well as between mobile and stiff polymers, translates into different results in terms of polymer signal reduction, suggesting that the relaxation filter can also be used for obtaining information on the polymer structure.

A targeted rheological bioink development guideline and its systematic correlation with printing behavior

Bioprinting for tissue or disease models is a promising but complex process involving biofabrication, cell culture and a carrier material known as bioink. The native extracellular matrix (ECM), which forms the scaffold for cells in vivo, consists of several components including collagen as a gelling agent to confer mechanical stiffness and provide a substrate for cell attachment. Bioprinting therefore needs an artificial ECM that fulfils the same functions as its natural counterpart during and after the printing process. The combination of bioink materials determines the immune response of the host, cell compatibility and adhesion. Here we evaluate multi-material blending with four pre-selected components using a design of experiments (DoE) approach. Our exemplary designed hydrogel is highly reproducible for the development of artificial ECM and can be expanded to incorporate additional requirements. The bioink displays shear-thinning behavior and a high zero-shear viscosity, which is essential for the printing process. We assessed the printing behavior of our bioink over a wide range of the key process parameters for extrusion-based bioprinting (temperature, pressure, feed rate, and nozzle geometry). Several processing temperatures were linked by rheological measurements directly to the 3D printing process. The printing results were evaluated using a self-developed categoric strand screening process, varying the feed rate and pressure with a fixed nozzle. Accordingly, nozzles differing in size and shape were evaluated and the interactions between printing pressure and feed rate were characterized separately by applying a modified O-R-O test. We tested the short-term cultivation stability of our bioink to mimic the hypothermic and hyperthermic conditions of the human body. As result we present an expandable concept for bioink development and a highly reproducible and well-characterized procedure for printing with the newly developed hydrogel. We provide detailed insights into the relationship between printing parameters, rheological parameters and short-term cultivation stability.

Microwave-Assisted Extraction and HPLC-UV-CD Determination of (S)-usnic Acid in Cladonia foliacea

During the years, many usnic acid (UA) conjugates have been synthesized to obtain potent endowed with biological properties. Since (S)-UA is less abundant in nature than (R)-enantiomer, it is difficult to source, thus precluding a deeper investigation. Among the lichens producing UA, Cladonia foliacea is a valuable (S)-UA source. In the present work, we report on a rapid HPLC-UV/PAD-CD protocol suitable for the analysis and the identification of the main secondary metabolites present in C. foliacea extract. Best results were achieved using XBridge Phenyl column and acetonitrile and water, which were both added with formic acid as mobile phase in gradient elution. By combining analytical, spectroscopical, and chiroptical analysis, the most abundant analyte was unambiguously identified as (S)-UA. Accordingly, a versatile microwave-assisted extractive (MAE) protocol, assisted by a design of experiment (DoE), to quantitatively recover (S)-UA was set up. The best result in terms of UA extraction yield was obtained using ethanol and heating at 80 °C under microwave irradiation for 5 min. Starting from 100 g of dried C. foliacea, 420 mg of (S)-UA were achieved. Thus, our extraction method resulted in a suitable protocol to produce (S)-UA from C. foliacea for biological and pharmaceutical investigation or commercial purposes.

QbD approach to downstream processing of spray-dried amorphous solid dispersions - a case study

In the current study, we demonstrate a structured approach to downstream process development for spray dried amorphous solid dispersions. Direct compression is generally not suitable due to typically poor flow of spray dried powders in tablets. Roller compaction (RC) is therefore the method of choice to enable spray dried dispersion downstream processing. Here, a structured experimental design of RC process parameters was used. The objective was to identify process conditions that lead to improved powder flow without compromising tablet robustness. Ten blends were compacted using different process parameters, and subsequently compressed into tablets. The impact of process parameters on granules and tablet properties was analyzed. We demonstrate that compaction force, gap and mesh aperture have major impact on RC outcomes. A combination of large gap and low force was identified as optimum combination of RC process parameters leading to powder flow improvement that could guarantee low tablet weight variation and at the same prevented loss of blend compressibility.

Use of Autochthonous Lactiplantibacillus plantarum Strains to Produce Fermented Fish Products

The present research was aimed to the optimization of the production of a fish fermented salami-like product using autochthonous Lactiplantibacillus plantarum starters. The activity was performed through two phases: (1) Optimization of fermented fish product composition by using a 2^k-p Fractional Factorial Design: the variables tested were nitrites (0–150 ppm), salt (2.5–7.5%), sucrose (0–4%), white pepper (0–0.10%), and fermentation temperature (10–30°C); (2) Product realization and evaluation of its microbiological profile [aerobic microbiota (APC), Pseudomonadaceae (PSE), Enterobacteriaceae (E), and lactic acid bacteria (LAB) populations], chemico-physical parameters (pH and a_w), and sensorial quality (odor, texture, color, and overall acceptability) during its storage at 4°C for 21 days. In the first step, the fish pulp was mixed with the appropriate amounts of ingredients, according to the experimental design; each batch was individually inoculated with the studied starter (L. plantarum 11, L. plantarum 69, and L. plantarum DSM1055) at 10⁷ cfu/g and incubated at 10, 20, or 30°C for 7 days. The lowest fermentation time (time to reach pH 4.4) was obtained with 4% sucrose, 100 ppm nitrite and a process temperature of 30°C. In the second step, salami-like were produced according to the individuated formulation and inoculated with the studied starters (10⁷ cfu/g); the fish mixture was stuffed into a natural casing and left to ferment at 30°C for 7 days. The use of the selected strains not only assured a correct fermentation but reduced the process time at only 2 days; during refrigerated storage, a good microbiological, chemico-physical and sensorial quality of the final product was recorded for at least 21 days.

Upstream development of Escherichia coli fermentation process with PhoA promoter using design of experiments (DoE)

In this work, a fed-batch fermentation development was performed with recombinant E. coli carrying the PhoA promoter system. The phosphate concentrations tested for this PhoA strain, 2.79 mM to 86.4 mM, were beyond the concentrations previously evaluated for cell growth and product titer. The results from the scouting work was used for design of experiments (DoE) where a range of phosphate levels from 27.1 mM to 86.4 mM was simultaneously evaluated with temperature, pH and DO set points. Definitive screening was used to evaluate these parameters simultaneously and the results indicate that fermentation temperature and phosphate content are the major contributors of product titer. The other factors tested such as pH had a minimal effect and DO had no impact on product titer.