Solvent Content Research Articles

Development of Thermosensitive Hydrogel Mouthwash Loaded with Zingiber zerumbet Extract for Enhanced Oral Thrush Treatment

BackgroundOral thrush, caused by Candida albicans, is currently treated under guidelines by using topical antifungal pharmaceutical formulations such as lozenges and liquid gargles. Using these drugs may cause irritation and adverse reactions. Moreover, there is a short exposure time to reach the lesion, which may result in low effectiveness of the treatment. Therefore, the research group aimed to develop mouthwash solutions that can form gel at oral temperature containing Zingiber zerumbet rhizome extracts, which work as an active substance inhibiting fungi. MethodsThe development process began with the extraction of substances from Zingiber zerumbet rhizome using hexane and the analysis of the active substance by HPLC. Antifungal and anti-inflammatory activities of the extracts were evaluated. Hydrogel mouthwash was prepared by varying the type and concentration of polymer, solvent, and mucoadhesive agent. The optimized formulation was then evaluated for its properties. ResultsZingiber zerumbet rhizome extracts, containing 16.29±0.39 % zerumbone, demonstrated both antifungal and anti-inflammatory activities against Candida albicans. The extract also had anti-inflammatory activity when tested by the proteinase inhibitory test, with a percentage inhibition of 86.15±10.96 %. Two thermosensitive hydrogels, poloxamer P407 and P188, were applied and compared as gel-forming agents. It was found that the optimized formulation is composed of 15 % (w/w) poloxamer P407, 0.05 % (w/w) carbopol as a mucoadhesive agent, and 5 % (v/v) ethanol. Transition time and transition temperature of the optimized thermosensitive hydrogel formula were 27.76±1.25 s and 36±1.00 °C, respectively. The viscosity at shear rate 1 S-1 and 25 °C of the optimized formulation was 0.13±0.06 Pa.s, which is suitable for pouring out of the bottle and gargling. ConclusionThis study demonstrates a novel approach to developing thermosensitive hydrogel mouthwash formulations, leveraging Zingiber zerumbet rhizome extracts for enhanced therapeutic efficacy against oral candidiasis. These formulations offer prolonged contact time with affected areas, potentially improving treatment outcome.

Solubility effect of deep eutectic solvent and ethanol concentration on corncob lignin extraction

This research investigates the solubility effect of deep eutectic solvent (DES) mass ratio and ethanol–water solution concentration on corncob lignin extraction. The objective is to propose a solubility matching technique based on like-dissolves-like theory to optimize lignin extraction conditions. The choline chloride (ChCl):lactic acid (LA) mass ratio that maximized lignin extraction was determined by varying DES mass ratio between 1:2 and 1:5, and ethanol–water solution (5–95 % (v/v)) was added to precipitate lignin. By using the solubility matching technique, the maximum lignin extraction was achieved at 1:4 ChCl:LA mass ratio, and 70 % (v/v) ethanol–water concentration yielded the highest lignin precipitation. Lignin is highly soluble where the solubility (δ-values) of lignin, DES, and precipitant are similar. Unlike conventional trial-and-error methods, the solubility matching technique relies on δ-values calculated by the Hildebrand and Scott equation. The proposed technique can also be applied to optimize the extraction conditions of other biomass materials.

Selection of solvent and positive control concentration for enhanced Ames test conditions for N-nitrosamine compounds

The Ames test is a widely used bacterial mutagenicity assay to evaluate the potential of chemical compounds to induce mutations. In recent years, there has been growing concern regarding the presence of N-nitrosamines in pharmaceuticals, food, and other consumer products. N-Nitrosamines are probable mutagens and carcinogens. To address the reduced sensitivity of the standard Ames test for N-nitrosamines, particularly N-nitrosodimethylamine, the European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) have recently published recommendations for enhanced Ames test (EAT) conditions. However, there is a lack of clear guidance on the selection of N-nitrosamine positive control concentrations, particularly for 1-cyclopentyl-4-nitrosopiperazine, and the amount of solvent to be used in the EAT. This study aims to address the current gap in concentration and volume specifications by providing a comprehensive guide to set up enhanced Ames test conditions specifically for N-nitrosamine compounds using appropriate amounts of solvent, new solvents, and strain-specific positive control concentrations.

Comparative Study Between Design and Parameter Adjustment for Profit Maximization of Low-Density Polyethylene (LDPE) Production in High-Pressure Tubular Reactor

Low density polyethylene (LDPE) market becomes increasingly competitive and profit margins are tightening, manufacturers must create solutions to optimize profit in LDPE high pressure tubular reactors. Thus, in this study, the optimization of LDPE was proposed and conducted by improving the design and parameter adjustment of the LDPE tubular reactor. A mathematical model was developed and validated with industrial data by using MATLAB R2021. Input parameter study was carried out to investigate the effect of initiator concentration (CI), monomer concentration (CM), and solvent concentration (CS) to the ethylene conversion rate, reaction temperature rate, and final product grade, respectively. The CM was identified as the most significant parameter to influence LDPE polymerization process. CM increment results in the highest reaction temperature peak, which was originating from 249.58 to 299.21oC. The highest MFI value was also obtained when the CM was increased from 0.01954 to 0.01979 mol/cm3. Then, a comparative study between design and parameter adjustment for profit maximization in LDPE High Pressure Tubular Reactor was conducted. With the profit of RM166.83 million/year, compared to RM106.83 million/year, double reaction zones demonstrates that it has much better ethylene conversion rate compared to single reaction zone with optimization.

Piperazine-Based Mixed Solvents for CO2 Capture in Bubble-Column Scrubbers and Regeneration Heat

This work used piperazine (PZ) as a base solvent, blended individually with five amines, which were monoethanolamine (MEA), secondary amines (DIPAs), tertiary amines (TEAs), stereo amines (AMPs), and diethylenetriamine (DETA), to prepare mixed solvents at the desired concentrations as the test solvents. A continuous bubble-column scrubber with one stage (1 s) was first used for the test. Six parameters were selected, including the type of mixed solvent (A), the ratio of mixed solvents (B), the solvent feed rate (C), the gas flow rate (D), the concentration of the mixed solvents (E), and the liquid temperature (F), each one having five levels. Using the Taguchi experimental design, only 25 runs were required. The outcome data, such as the absorption efficiency (EF), the absorption rate (RA), the overall mass-transfer coefficient (KGa), and the absorption factor (φ), could be determined under steady-state conditions. The optimal mixed solvents were found to be A1 (PZ + MEA) and A2 (PZ + DIPA). The parameter importance and optimal conditions for EF, RA, KGa, and ϕ were determined separately; the verification of all optimal conditions was successful. This analysis found that the importance of the parameters was D > C > A > E > B > F, and the gas flow rate (D) was the most important factor. Subsequently, multiple-stage scrubbers were used to capture CO2. Comparing 1 s and 3 s (three-stage scrubber), EF, RA, KGa, and φ increased by 33%, 29%, 22%, and 38%, respectively. The desorption tests for the four optimal scrubbed solutions, including multiple stages, showed that the heat of regeneration for the three scrubbers was 3.57–8.93 GJ/t, in the temperature range of 110–130 °C, while A2 was the best solvent. Finally, the heat regeneration mechanism was also discussed in this work.

Kinetic characteristics of bornite and chalcopyrite dissolution in nitric acid

The kinetic characteristics of dissolution of copper-bearing sulfides – chalcopyrite (CuFeS₂) and bornite (Cu₅FeS₄) – in nitric acid were studied. The kinetics of the dissolution process was described using a compressible nucleus model. Chalcopyrite of the Vorontsovskoye deposit and bornite of the Karabash deposit were used as research objects. Solution and cake samples were analyzed by optical emission spectrometry and X-ray fluorescence analysis, respectively. The results obtained were processed in the MS Excel software package. The influence of various factors, including temperature, solvent concentration, particle size, and process duration on the dissolution degree of minerals was studied. The process parameters were varied as follows: temperature – from 35 to 95°C; HNO₃ concentration – from 1 to 9 mol/dm³; particle size – from +0.1 to 0.056 mm; duration – from 0 to 60 min. It was established that an increase in temperature and acid concentration leads to a significant increase in the degree of dissolution of both chalcopyrite and bornite. A decrease in particle size also contributes to a more efficient dissolution of both minerals in nitric acid. The calculated activation energy values were 55 kJ/mol for chalcopyrite and 43 kJ/mol for bornite, which is characteristic of the kinetic region of the process. The reaction orders in terms of reactant were determined: 1.62 for chalcopyrite and 1.57 for bornite. In terms of particle size, these were -1.16 for chalcopyrite and -2.53 for bornite. On this basis, generalized equations of dissolution kinetics for both minerals were derived. The results obtained allow an assumption about the kinetic nature of dissolution of chalcopyrite and bornite under the studied conditions.

Techno-economic analysis and optimisation of Piperazine-based Post-combustion carbon capture and CO2 compression process for large-scale biomass-fired power plants through simulation

This study aims to investigate a cost-effective and energy-efficient amine-based post-combustion carbon capture (PCC) process for large-scale supercritical biomass-fired power plants (SC BFPP). Thus, we have quantified the energy and economic performance of the PCC process with different configurations and solvents. Three process configurations which included the standard configuration, the absorber intercooler (AIC) with the advanced flash stripper (AFS) and the AIC, AFS and side stream extraction (SSE) were simulated in Aspen Plus® V11 using 30 wt% and 40 wt% piperazine (PZ) as solvent. In addition to this, CO2 compression trains using the heat pump (HP) and supercritical CO2 cycle (s-CO2) were also simulated. Sensitivity analysis of the PCC process was carried out to investigate the impact of important parameters on the energy performance of the process. Furthermore, energy analysis shows that a minimum energy consumption of 2.78 GJ/tCO2 was achieved with the PCC process using 40 wt% PZ, a combination of the AIC, AFS and SSE for capture and s-CO2 for compression. This achieved a significant energy saving of 1.01 GJ/tCO2 compared with the standard PCC process using 30 wt% monoethanolamine that is used as the benchmark in this study. The economic analysis results showed that the minimum CO2 capture cost of 55.70 $/tCO2 was achieved using the AIC-AFS-SSE-sCO2 configuration and 40 wt% PZ as solvent. This represents a 19.5 % reduction in cost compared with the standard 40 wt% PZ process with a cost of 69.18 $/tCO2. The optimisation of the PZ-based PCC process was carried out to determine the optimal solvent concentration with the minimum carbon capture cost. It was found that the optimal PZ concentration for the PCC process based on standard and AFS configurations were 37.5 wt% and 32.5 wt%, respectively. The optimisation of the stripper pressure for the minimum carbon capture cost was conducted. As a result, compared with the standard PCC process using 40 wt% PZ, the energy consumption and CO2 capture cost of the optimised process at the suggested pressure of 7 bar were reduced by 41.6 % and 32.4 %, respectively.

Hybrid Screen Printable Electrolyte for Large‐Scale Flexible Electrochromic Display Production

AbstractThis study presents the development of a novel screen printable quasi‐solid polymer electrolyte (p‐QSPE) for Electrochromic Displays (ECDs) applications. p‐QSPE is composed of three key components: polyvinylidene fluoride (PVDF), a high‐dielectric constant polymer that ensures high ionic conductivity in solid‐state; glyceril propoxy triacrylate (GPTA), a UV‐cross‐linkable monomer that provides structure and durability for overprinting; titanium dioxide (TiO₂) nanoparticles, which modulate the electrolyte's rheological properties for screen printing; reducing the solvent (PC:EC) content to only 35.90 wt.%. Electrochemical Impedance Spectroscopy (EIS) revealed that this well‐designed formulation achieved an ionic conductivity of 1.17 × 10−3 S cm−1 at room temperature, surpassing the threshold required for commercial applications. Moreover, p‐QSPE facilitated the production of fully screen printed ECDs in an industrial printing line, streamlining their production process and achieving an optimal balance between printability, overprint resilience, and device performance. Operational tests for the ECDs showed fast switching times (<6 s for t90 and <2 s for t75) across a wide temperature range (−20 °C to 80 °C). Additionally, the electrolyte demonstrated low charge consumption (2.10 ± 0.11 mC cm−2) and a lifespan exceeding 10 000 cycles. These results highlight the potential of p‐QSPE as a screen printable, high‐performance electrolyte, capable of advancing ECD manufacturing by enabling the production of fully screen‐printed, performing ECDs.

RSM and ANN-Based Optimized Ultrasound-Assisted Extraction of Functional Components from Olive Fruit (cv Arbequina): Assessment of Antioxidant Attributes and GC-MS Metabolites Profiling.

The current study devises an optimized ethanolic extraction for efficient recovery of high-value components from Pakistani olives (cv. Arbequina) using response surface methodology (RSM) and artificial neural networking (ANN). Four factors such as time, temperature, solvent concentration, and solute weight (g/100 mL) were evaluated as independent variables for determining the response (% yield). The results obtained under optimum extraction conditions such as duration (25 min), temperature (45 °C), solvent concentration (65 %; ethanol: water v/v), and solute (7.50 g/100 mL) offered bioactives extract yield of 40.96 % from Arbiquina olives. The analysis of variance (ANOVA) for the RSM model showed significant p-values and a correlation coefficient (R2) of 0.9960, confirming model's reliability. The results of ANN, which employed the multilayer perceptron design, were fairly in line with the findings of the experiments. The antioxidant characteristics and GC-MS metabolite profile of the obtained extracts were examined. Arbequina olive extract (AOE) demonstrated very good antioxidant ability in terms of total phenolic, total flavonoid contents, and DPPH radical scavenging. The GC-MS analysis of AOE confirmed the presence of several bioactives, including oleic acid (36.22 %), hydroxytyrosol (3.95 %), tyrosol (3.32 %), β-sitosterol (2.10 %), squalene (1.10 %), sinapic acid (0.67 %), α-tocopherol (0.66 %), vanillic acid (0.56 %), 3,5-di-tert-butylcatechol (0.31 %), and quercetin (0.21 %). The suggested optimized extraction method can be employed to efficiently extract a wide variety of high-value components from olives with potential for nutraceutical applications.

Optimization of microwave-assisted hydrolysis of glucose from oil palm empty fruit bunch

Hydrolysis of oil palm empty fruit bunches (OPEFB) using microwave as an energy source is carried out to produce sugar with mild operating conditions. One way to find the best conditions that can obtain high-quality sugar is to optimize the hydrolysis process. In this study, optimization was carried out using Response Surface Methodology (RSM) with a Central Composite Design (CCD) experimental design. Estimated variables to affect the hydrolysis process are the ratio of OPEFB to solvent (X1: 1:20-4:20 g/ml), solvent concentration (X2: 0.5-1.5%), and hydrolysis time (X3: 5-15 minutes). Hydrolysis success parameters were measured by hydrolysis temperature (Y1), glucose (Y2), fructose (Y3), and total sugar (Y4) concentration. The optimization results show that the three independent variables contribute 53.25% to the hydrolysis temperature and 86.42% to the sugar concentration. The recommended operating conditions were hydrolysis with the ratio of OPEFB to solvent of 4:20 g/ml, 0.50% solvent concentration, and done for 10 minutes. The hydrolysis temperature cannot be optimized because there is a mismatch in the temperature model analysis. The application of these conditions is predicted to produce glucose, fructose, and total sugar of 315.51; 258.24; 573.85 mg/L. The last step is to validate these conditions in the laboratory to get the actual value. Actual glucose, fructose, and total sugar obtained were 300.40; 245.44; 545.84 mg/L. The error in this study is less than 5% which indicates the actual value is following the predicted value. © 2001 Elsevier Science. All rights reserved

Optimization of ultrasound-assisted extraction method of Syzygium cumini leaves based on extraction yield, content of bioactive compound, and inhibition of dipeptidyl peptidase IV enzyme activity using response surface methodology

Syzygium cumini leaves show potential to be developed as herbal medicine products against diabetes mellitus due to their high polyphenol contents. S. cumini was optimized using response surface methodology and Box–Behnken design with solvent solid ratio, solvent concentration, time and temperature, extraction yield, total flavonoid content (TFC), total phenolic content (TPC), and dipeptidyl peptidase IV (DPP-IV) enzyme inhibitory activity to obtain an effective and optimal extraction method. The conditions were achieved using a 70% ethanol solvent for the extraction, with a solvent–solid ratio of 21 v/w and run at 20°C for 30 min. The results showed an extraction yield of 83.875%, with TFCs measuring at 3.068 mg QE/g, TPCs of 65.029 mg GAE/g, and DPP-IV enzyme inhibition activity of 66.079%. Further analysis of the phytochemical profile using untargeted liquid chromatography-high-resolution mass spectrometry showed the presence of amine, amide, and fatty acid derivatives as major constituents. In addition, major flavonoids observed were myricetin and myricitrin, accounting for 0.2%. Ursolic acid and 25-azacholesterol accounted for 1.03% of the phenolics detected.

Anthocyanin Extraction from Roselle (Hibiscus sabdariffa L.) Calyces: A Microwave-Assisted Approach Using Box-Behnken Design

Roselle (Hibiscus sabdariffa L.) is a widely consumed edible flower, often utilized as a natural coloring agent. The bright red color of roselle is due to its anthocyanin content. Beyond their role as colorants, anthocyanins are known for their potent antioxidant properties, which have drawn significant interest for their potential health benefits. To fully harness the advantages of roselle's anthocyanins, developing a reliable extraction method is crucial. This study aimed to establish a fast, efficient, and environmentally friendly extraction technique using microwave-assisted extraction (MAE). Key factors, such as temperature (30, 65, and 100 °C), solvent concentration (30%, 50%, and 70% ethanol in water), and solvent-to-solid ratio (10:1, 25:1, 40:1), were optimized using the Box-Behnken design combined with response surface methodology. The extraction time (5-30 minutes) was also evaluated to maximize anthocyanin recovery. Two major anthocyanins, delphinidin-3-sambubioside and cyanidin-3-sambubioside, were identified using UHPLC-PDA-QToF-MS and quantified using a cyanidin-3-glucoside calibration curve. The optimal extraction conditions were found to be 72 °C, using 70% ethanol in water with a 40:1 solvent-to-solid ratio for 15 minutes. This method was validated with high accuracy (>98% recovery) and precision (CV <6%). It was successfully applied to quantify the anthocyanin content in both purple and red roselle varieties. This rapid and effective MAE method offers a more sustainable, energy-efficient, and time-saving alternative to conventional extraction methods, benefiting industries that rely on natural colorants and antioxidants.

Ultrasound-assisted extraction of scopolamine and hyoscyamine from Hyoscyamus niger roots using central compost design

Hyoscyamus niger is an important medicinal plant used in medicine and contains tropane alkaloid compounds such as hyoscyamine and scopolamine. In this study, after the selection of the solvent for extracting hyoscyamine and scopolamine, the central composite design of the response surface methodology was used to study the effect of solvent concentrations (0, 25, 50, 75, and 100 %), temperatures (25, 30, 35, 40, and 45 °C) and ultrasonication times (10, 20, 30, 40, and 50 min). The hyoscyamine and scopolamine content were obtained by HPLC-DAD. The results indicated that the predicted optimal condition for hyoscyamine and scopolamine extraction from H. niger root was as follows. Hyoscyamine: 100 % methanol, temperature 45 °C and ultrasonication time 10 min, obtained 172.06 μg/g dry weight; and scopolamine: 98.50 % methanol, temperature 25 °C and ultrasonication time 10 min, provided 229.48 μg/g dry weight. To confirm the predicted extraction conditions, a separate experiment was conducted, and the results showed that the hyoscyamine and scopolamine contents were 164.72 and 209.23 μg/g dry weight, respectively.

An Examination of the Transport and Acoustics Properties of B3 Vitamins and Aqueous MgCl2 Salt at Various Temperatures and Concentrations

AbstractForecasting various forms of intermolecular contact and the degree to which the solute and solvent are bonded is highly advantageous when using thermo‐acoustical and volumetric data. Both salts and vitamins are abundant in the human body. A variety of thermo‐acoustical and volumetric properties (viz. velocity [U], density [ρ], adiabatic compressibility [β], surface tension [σ], specific heat ratio [γ], acoustic impedance [Z], relative association [RA], relaxation strength [r], isothermal compressibility [kT], and nonlinearity parameter [B/A]) are investigated in this study. Of the vitamin B3 + H2O and vitamin B3 + H2O + MgCl2 systems have been examined. Through solvation and hydrogen bonding, these characteristics are utilized to describe the interactions between solutes and solvents. Compressibility explains the qualitative intermolecular elastic forces that exist between the molecules of the solvent and the solute. The electrostatic field of ions has formed the basis for discussions on the structural arrangement of molecules in electrolyte solutions. The volumetric and thermoacoustic characteristics exhibit concentration‐dependent changes, suggesting the existence of molecular interactions in both systems. The vitamin B3 molecule shows stronger molecular contact at higher solvent concentrations, although it interacts most molecularly with MgCl2 solvents. This suggests that magnesium molecules are more suited for the attachment of vitamin B3 molecules than are water molecules.

The Correlations between Microstructures and Color Properties of Nanocrystalline Cellulose: A Concise Review.

Cellulose nanocrystals (CNCs) are a green resource which can produce photonic crystal films with structural colors in evaporation-induced self-assembly; CNC photonic crystal films present unique structural colors that cannot be matched by other colored materials. Recently, the mechanisms of CNC photonic crystal films with a unique liquid crystal structure were investigated to obtain homogenous, stable, and even flexible films at a large scale. To clarify the mechanism of colorful CNC photonic crystal films, we briefly summarize the recent advances from the correlations among the preparation methods, microstructures, and color properties. We first discuss the preparation process of CNCs, aiming to realize the green application of resources. Then, the behavior of CNCs in the formation of liquid crystal phases is studied, considering the influence of the CNCs' size and shape, surface properties, and the types and concentrations of solvents. Finally, the film formation process of CNCs and the control of structural colors during the film formation are summarized, as well as the mechanisms of CNC photonic crystal films with full color. In summary, considering the above factors, obtaining reliable commercial CNC photonic crystal films requires a comprehensive consideration of the subsequent preparation processes starting from the preparation of CNCs.

Ultrasonic-assisted extraction of polyphenolics from Schrebera swietenioides Roxb.: An optimization using response surface methodology

Schrebera swietenioides Roxb is an important medicinal plant used for the treatment of various diseases by the indigenous communities. However, this plant is still underexplored in the modern scientific era. Specifically, the leaves of the plant are reported to contain various medicinal properties such as antioxidant, antimicrobial, anti-inflammatory, and antipyretic activity. Herewith, the present work demonstrates and optimizes the extraction process usingan ultrasonic system and comopared the results with conventional extraction methods. Optimization was performed by combining first and second-order polynomial designs at different levels using Plackett-Burman and Central-Composite designs. A total of 31 experiments were conducted at different levels, including ultrasonic power (10–40 %), solvent-to-sample ratio (20–50 mL/g), solvent concentration (50–80 %), and HCl normality (0.2–1 N). The findings of the study suggest a significant (p<0.05) influence of extraction parameters on the extraction yield of the response variables, including total phenol (TPC), total flavonoid (TFC), total tannin (TTC), and the antioxidants activity. Further, the predicted values demonstrated good agreement with the experimental values, exhibiting a high (R2>95%) coefficient of determination and a non-significant lack of fit. At the optimized condition, the experimental values of TPC, TFC, TTC and antioxidants (DPPH, ABTS, FRAP) activity were found near the model predicted values. The HPLC-PDA analysis identified ten polyphenolic compounds, among which rutin hydrate (12.991±0.003 mg/g DW), followed by phloridzin (6.660±0.001 mg/g DW), and chlorogenic acid (3.380±0.008 mg/g DW) were the most prominent compounds. Furthermore, the optimized extract showed effective antibacterial activity against Bacillus subtillis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus species. In conclusion, the obtained results indicate that the proposed optimization strategy can be utilized to enhance the yield of polyphenolics from the target species with possibility of its application in therapeutics values.

Control of encapsulation efficiency and morphology of poly(lactide-co-glycolide) microparticles with a diafiltration-driven solvent extraction process

The removal of organic solvents during the preparation of biodegradable poly(D,L-lactide-co-glycolide) (PLGA) microparticles by an O/W- solvent extraction/evaporation process was investigated and controlled by diafiltration. Emulsification and steady replacement of the aqueous phase were performed in parallel in a single-vessel setup. During the process, the solidification of the dispersed phase (drug:PLGA:solvent droplets) into microparticles was monitored with video-microscopy and focused beam reflectance measurement (FBRM) and the residual solvent content was analyzed with headspace gas chromatography (organic solvent) and coulometric Karl-Fischer titration (water). Microparticles containing dexamethasone or risperidone were characterized with regard to particle size, morphology, encapsulation efficiency and in-vitro release. Diafiltration-accelerated solvent extraction shortened the process time by accelerating solidification of dispersed phase but reduced the residual dichloromethane content only in combination with increased temperature. Increasing the diafiltration rate increased particle size, porosity, and the encapsulation efficiency of risperidone. The latter effect was particularly evident with increasing lipophilicity of PLGA. A slower and more uniform solidification of end-capped and increased lactide content PLGA grade was identified as the reason for an increased drug leaching. Accelerated solvent extraction by diafiltration did not affect the in-vitro release of risperidone from different PLGA grades. The initial burst release of dexamethasone was increased by diafiltration when encapsulated in concentrations above the percolation threshold. Both porosity and burst release could be reduced by increasing the process temperature during diafiltration. Residual water content was established as an indicator for porosity and correlated with the burst release of dexamethasone.

Optimizing phlorotannins extraction from Fucus vesiculosus using Box-Behnken design: Unveiling techniques for enhanced antioxidant activity and metabolic enzyme inhibition

Phlorotannins, phenolic compounds found in brown macroalgae, exhibit potential bioactive effects. This study evaluated the extraction of phlorotannins from Fucus vesiculosus using conventional and ultrasound-assisted extraction (UAE) methods, focusing on solvent-material ratio, solvent concentration, extraction time, and sonication power for UAE. The experiments, designed using a Box-Behnken design, measured total phlorotannin content (TPhC), DPPH, FRAP, and ABTS. The conventional method, under optimal conditions, produced TPhC, DPPH, FRAP, and ABTS values of 512.25 ± 14.26 mg PGE/100 g, 29.70 ± 1.40 mg TE/100 g, 589.57 ± 15.06 mg TE/100 g, and 332.73 ± 31.03 mg TE/100 g, respectively. The UAE method, under its optimal conditions, yielded higher values: 954.00 ± 33.65 mg PGE/100 g, 146.35 ± 3.30 mg TE/100 g, 1037.61 ± 32.93 mg TE/100 g, and 809.95 ± 46.58 mg TE/100 g. The extracts were tested for inhibitory effects on α-amylase and α-glucosidase, with the purified UAE extract showing greater inhibition of α-amylase (IC50 = 7.06 ± 0.67 μg/mL) compared to acarbose (IC50 = 14.63 ± 0.28 μg/mL). For α-glucosidase, acarbose had higher activity (IC50 = 11.54 ± 0.04 μg/mL) than the UAE purified extract (IC50 = 15.04 ± 0.07 μg/mL). UHPLC-qTOF-MS analysis identified various phlorotannin derivatives, with Tetrafucotetraphlorethol (m/z 993) only in the UAE purified extract. This study concludes that purified phlorotannin extract from UAE can potentially regulate α-amylase and α-glucosidase, enzymes linked to metabolic disorders like diabetes and obesity.

Accelerated removal of solvent residuals from PLGA microparticles by alcohol vapor-assisted fluidized bed drying

The removal of residual solvents from biodegradable poly(D,L-lactide-co-glycolide) (PLGA) microparticles by fluidized bed drying was investigated. Microparticles were prepared by the O/W solvent extraction/evaporation method and the influence of various process and formulation parameters on the secondary drying was studied. PLGA microparticles and films were characterized for residual organic solvent and water content, recrystallisation, surface morphology, drug loading and in-vitro release of the drugs dexamethasone and risperidone. While alcohol-free fluidized bed drying decreased the residual dichloromethane content only from about 7 % (w/w) to 6.4 % (w/w) (18 °C) or 3.2 % (w/w) (35 °C) within 24 h, 140 mg/L methanol vapor in purge gas facilitated almost complete removal of dichloromethane or ethyl acetate from microparticles (0–0.11 % (w/w) after 6 h). By controlling the alcohol concentration and temperature of the purge gas, the alcohol absorption and complete removal was controlled. Risperidone increased the methanol absorption enhancing the plasticization. A high initial residual water content was identified to promote aggregation and was eliminated by starting fluidized bed drying without alcohol. Alcohol vapor-assisted fluidized bed drying accelerated microparticle manufacturing without affecting the redispersibility, the drug loading and the in-vitro release of risperidone and dexamethasone.

Development of a high throughput cytochrome P450 ligand-binding assay

Human cytochrome P450 enzymes are membrane-embedded monooxygenases responsible for xenobiotic metabolism, steroidogenesis, fatty acid metabolism, and vitamin metabolism. Their active sites can accommodate diverse small molecules and understanding these interactions is key to decoding enzymatic functionality and designing drugs. The most common method for characterizing small molecule binding is quantifying absorbance changes that typically occur when ligands enter the active site near the heme iron. Traditionally, such titrations are monitored by a spectrophotometer, requiring significant manual time, protein, and increasing solvents. This assay was adapted for semi-automated high throughput screening, increasing throughput 50-fold while requiring less protein and keeping solvent concentrations constant. This 384-well assay was validated for both type I and II shifts typically observed for substrates and heme-coordinating inhibitors, respectively. This assay was used to screen a library of ∼100 diverse imidazole-containing compounds which can coordinate with the heme iron if compatible with the overall active site. Three human cytochrome P450 enzymes were screened: drug-metabolizing CYP2A6 and CYP2D6 and sterol-metabolizing CYP8B1. Each bound different sets of imidazole compounds with varying Kd values, providing a unique binding fingerprint. As a final validation, the Kd values were used to generate pharmacophores to compare to experimental X-ray structures. Applications for the high-throughput assay include the following: 1) facilitating generation of pharmacophores for enzymes where structures are not available, 2) screening to identify ligands for P450 orphans, 3) screening for inhibitors of P450s drug targets, 4) screening potential new drugs to avoid and/or control P450 metabolism, and 5) efficient validation of computational ligand binding predictions.