Dissolution Ability Research Articles

Experimental Investigations on the Dissolution Process of Dolomite by Sulfate-Rich Geothermal Water: A Case Study of the Shuijing Hot Springs in Guizhou Province

The dissolution of dolomite can not only provide the chemical components in hot springs but also provide a high-quality reservoir for geothermal resources. However, there is still debate about the main controlling factors and mechanisms of the dissolution process of dolomite. The Shuijing hot springs in Guizhou Province are rich in SO42− and the geothermal reservoir is dolomite, which provides an excellent opportunity to understand the role of SO42− in the dissolution process of dolomite. In this paper, water–rock interaction experiments were conducted at different temperatures to study the effects of SO42−, pH, and CO2 on the dissolution of dolomite from the Shuijing hot springs geothermal reservoir. The results indicate that temperature is a significant factor affecting the chemical composition of hot springs water, with higher temperatures having a more pronounced effect on the dissolution of dolomite. At lower temperatures of 25 °C and 90 °C, the molar ratio of the released Ca2+ and Mg2+ during the dissolution of dolomite in the initial reaction stage generally approaches the Ca/Mg molar ratio of dolomite, exhibiting congruent dissolution. However, at elevated temperatures of 150 °C, the released Ca/Mg molar ratio surpasses the Ca/Mg molar ratio of dolomite, demonstrating an incongruent dissolution characteristic with Ca2+ being preferentially released over Mg2+. Additionally, the relative importance of CO2, SO42− and pH on the dissolution degree of dolomite is CO2 > SO42− > pH = 4 > pH = 7 > pH = 10. The promotion effect of SO42− on dolomite dissolution indicates that the greater the SO42− concentration, the stronger the dissolution of dolomite, and its dissolution ability is enhanced with the increase in temperature. Furthermore, the effect of CO2 on the dissolution of dolomite is stronger than that of SO42−, leading to the oscillating fluctuation trend of the released Ca2+ and Mg2+.

Biological and chemical properties of new multi-functional root canal irrigants.

To evaluate the efficacy of multi-functional root canal irrigating solutions in the removal of canal wall smear layers, antibacterial activity, cytotoxicity, and tissue dissolution efficacy. Forty single-rooted teeth were mechanically instrumented and irrigated with Triton, EndoJuice™, EDTA, and 0.9% saline. Each tooth was evaluated for smear layer removal using scanning electron microscopy. Antibacterial activity of the irrigants was assessed against Enterococcus faecalis biofilms using colony-forming unit analysis. Neutral red, clonogenic, and cytokinesis-block micronucleus assays were performed on Chinese hamster V79 cells to evaluate the short-term and long-term cytotoxicity and genotoxicity of the irrigants. Tissue dissolution efficacy was tested on shrimp meat placed in resorptive cavities prepared in root canals. EndoJuice™ and EDTA showed better smear layer removal than Triton in the coronal-third and middle-third of the canal walls. There was no significant difference between EndoJuice™ and EDTA. In the apical-third, EndoJuice™ removed the smear layer more effectively than EDTA and Triton. Specimens treated with saline were heavily smeared. Triton and sodium hypochlorite were similar in reducing intracanal E. faecalis counts, while specimens treated with EndoJuice™ had higher colony-forming units compared to Triton or sodium hypochlorite. EndoJuice™ was less cytotoxic and genotoxic compared to Triton. Sodium hypochlorite dissolved the most soft tissue, followed by Triton and EndoJuice™. EndoJuice™ was less toxic and more effective in smear layer removal. Triton demonstrated better antimicrobial activity and tissue dissolution efficacy. Evaluating the smear layer removal, antibacterial activity, toxicity, and tissue dissolution abilities of multi-functional root canal irrigants is essential to ensure their effectiveness and safety for clinical use in root canal treatment.

Periodate-chlorite oxidation for dicarboxylcellulose (DCC) production: activation strategies for the dissolution and visualization of oxidized groups distribution

There are different activation pathways for the oxidation of cellulose by the periodate-chlorite system: thermal activation, chemical activation and cellulosic pulp activation using chemical or mechanical pretreatments. This study aimed to compare the different possible activation methods applied on cellulose, focusing on their effects at the molecular scale (cellulose chain oxidation and degradation) and at the cell wall scale (visualization of oxidized groups locations). It is shown that the activation pathway has an influence on the relation between cellulose carboxylation and depolymerization. A method for analyzing the distribution of carboxyl groups at fiber surface and in the depth of the fiber wall was also developed, including sodium-to-silver ion exchange and SEM imaging with chemical contrast. Important differences in carboxyl group distribution were observed between the diverse activation treatments. Dissolution ability of oxidized PHK pulp at 3% in an alkaline aqueous solution was also assessed. The comprehensive comparison of the activation methods revealed that the combination of mechanical pretreatment and the addition of inert salt during the periodate stage, despite causing only slight oxidation activation, enhances the dispersity of carboxyl groups. This results in a higher dissolution ability in alkaline solvent while maintaining the cellulose DPv (viscosity-average degree of polymerization).

Effects of composite alkaline activator on mechanical properties and hydration mechanism of cemented paste backfill with cement kiln dust

To address the low utilization rate and environmental pollution of mine tailings (MT) and cement kiln dust (CKD), a CKD-based cemented paste backfill (CPB) material was prepared using quicklime (CaO) and sulfate (DH-7) as a composite alkaline activator (CAA), with CKD and slag as the cementitious material and MT as the aggregate. The optimal dosage of the new CAA was determined through unconfined compressive strength (UCS) analysis. The reaction products, pore structure, and cation dissolution ability of CKD-based CPB activated by CAA were investigated, analyzing the mechanism of strength enhancement. The results showed that the CAA enhanced the compressive strength of CKD-based CPB by improving the reactivity of calcium hydroxide. The addition of the CAA led to elevated the dissolution concentration of cations such as Ca and Si within the system, accelerating both the alkali activation reaction rate and the nucleation rate of the calcium aluminosilicate hydrate (C–(A–)S–H) gel. Furthermore, with the increase in CAA content, the pore structure of CKD-based CPB became more complex. Therefore, this study may provide novel insights into the preparation of cost-effective CPB materials with a high CKD content.

Anion Chemistry towards On‐Site Construction of Solid‐Electrolyte Interface for Highly Stable Metallic Zn Anode

AbstractReversibility of metallic Zn anode serves as the corner stone for the development of aqueous Zn metal battery, which motivates scrutinizing the electrolyte‐Zn interface. As the representative organic zinc salt, zinc trifluorosulfonate (Zn(OTf)2) facilitates a broad class of aqueous electrolytes, however, the stability issue of Zn anode remains crucial. The great challenge lies in the lack of Zn anode protection by the pristinely formed surface structure in aqueous Zn(OTf)2 electrolytes. Accordingly, an electrochemical route was developed to grow a uniform zinc trifluorosulfonate hydroxide (ZTH) layer on Zn anode as an artificial SEI, via regulation on metal dissolution and strong coordination ability of zinc ions. Co‐precipitation was proposed to be the formation mechanism for the artificial SEI, where the reduction stability of OTf− anion and the low‐symmetry layer structure of ZTH was unmasked. This artificial SEI favors interfacial kinetics, depresses side reactions, and well maintains its integrity during cycling, leading to a prolonged lifespan of Zn stripping/plating with a high DOD of ~85 %, and an improved cycling stability of ~92 % retention rate for V2O5/Zn cell at 1 A g−1. The unveiled role of anion on Zn anode drives the contemplation on the surface chemistry for the blooming aqueous rechargeable battery.

Anion Chemistry towards On-Site Construction of Solid-Electrolyte Interface for Highly Stable Metallic Zn Anode.

Reversibility of metallic Zn anode serves as the corner stone for the development of aqueous Zn metal battery, which motivates scrutinizing the electrolyte-Zn interface. As the representative organic zinc salt, zinc trifluorosulfonate (Zn(OTf)2) facilitates a broad class of aqueous electrolytes, however, the stability issue of Zn anode remains crucial. The great challenge lies in the lack of Zn anode protection by the pristinely formed surface structure in aqueous Zn(OTf)2 electrolytes. Accordingly, an electrochemical route was developed to grow a uniform zinc trifluorosulfonate hydroxide (ZTH) layer on Zn anode as an artificial SEI, via regulation on metal dissolution and strong coordination ability of zinc ions. Co-precipitation was proposed to be the formation mechanism for the artificial SEI, where the reduction stability of OTf- anion and the low-symmetry layer structure of ZTH was unmasked. This artificial SEI favors interfacial kinetics, depresses side reactions, and well maintains its integrity during cycling, leading to a prolonged lifespan of Zn stripping/plating with a high DOD of ~85 %, and an improved cycling stability of ~92 % retention rate for V2O5/Zn cell at 1 A g-1. The unveiled role of anion on Zn anode drives the contemplation on the surface chemistry for the blooming aqueous rechargeable battery.

Role of Niobium on the Passivation Mechanisms of TiHfZrNb High-Entropy Alloys in Hanks' Simulated Body Fluid.

A family of TiHfZrNb high-entropy alloys has been considered novel biomaterials for high-performance, small-sized implants. The present work evaluates the role of niobium on passivation kinetics and electrochemical characteristics of passive film on TiHfZrNb alloys formed in Hanks' simulated body fluid by analyzing electrochemical data with three analytical models. Results confirm that higher niobium content in the alloys reinforces the compactness of the passive film by favoring the dominance of film formation and thickening mechanism over the dissolution mechanism. Higher niobium content enhances the passivation kinetics to rapidly form the first layer, and total surface coverage reinforces the capacitive-resistant behavior of the film by enrichment with niobium oxides and reduces the point defect density and their mobility across the film, lowering pitting initiation susceptibility. With the high resistance to dissolution and rapid repassivation ability in the aggressive Hanks' simulated body fluid, the TiHfZrNb alloys confirm their great potential as new materials for biomedical implants and warrant further biocompatibility testing.

Research on Wellbore Blockage Mechanism and Blockage Removal Technology of Shale Gas Wells

Abstract With the continuous extension of development time, the production decline of single well is accelerated, and the problem of wellbore blockage in shale gas wells is prominent. The problem of wellbore blockage seriously restricts the stable production and efficient development of gas fields. In this paper, the ‘micro + macro’ analysis method is used to study the blockage. It is found that the wellbore blockage mainly includes corrosion, scaling products and a small amount of clay minerals brought by the reservoir during gas production. In the process of production, corrosion and scaling mechanism work together. Acidic gas such as CO2 in shale gas are dissolved in high-salinity formation water, causing electrochemical corrosion of the string. The formation of corrosion products will promote the deposition and adsorption of inorganic scales. The uneven accumulation of corrosion product films will enhance the surface roughness of the substrate and accelerate the deposition of scale samples around the crystal nucleus. At the same time, scaling will cause corrosion under the scale of the pipe string. Cl− can penetrate into the film through the micropores covering the product film on the metal surface, and pitting corrosion occurs to corrode the pipe string. Finally, the corrosion and scaling products together cause the pipe string to be blocked. Based on the analysis results of blockages and water samples, a blockage removal liquid system was developed according to the blockage mechanism. It has a high dissolution ability and the corrosion of 125SG, 155V and N80 steel sheets at 60°C for 4h is less than 1 g/(m2·h), which meets the requirements of industry standards. This system can inhibit the secondary precipitation of metal ions, has low corrosion damage to oil and casing, can remove wellbore blockage, does not need to flow back, will not cause secondary damage to the reservoir. It can provide guiding significance for similar shale gas well wellbore blockage removal.

Effect of lipid type on betulin-stabilized water-in-oil Pickering emulsion: emulsion properties, in vitro digestion, and betulin bioaccessibility.

The Pickering emulsion delivery technique is widely acknowledged for its efficacy in serving as a carrier that can encapsulate functional components effectively. Previous studies have shown significant differences in the stability of Pickering emulsions composed of different oil phases and in the bioaccessibility of the encapsulated functional ingredients. This study therefore investigated the effects of different carrier oils in the betulin self-stabilized water-in-oil (W/O) Pickering emulsion on the stability of the emulsion and bioaccessibility of betulin. The results showed that the oil type was one of the main factors affecting the stability of the emulsion. Palm oil and coconut oil provided better storage stability and centrifugal stability due to the high saturated fatty acid content. The bioavailability of betulin correlated significantly with the composition and characteristics of fatty acids in carrier oils. Carrier oils rich in low-saturation long-chain fatty acids tended to release more free fatty acids (FFAs), thus forming larger and more mixed micelles with stronger swelling and dissolution ability, resulting in a relatively high bioaccessibility of betulin. In contrast, the bioaccessibility of betulin in the emulsion prepared by coconut oil (with high saturated fatty acid content) was relatively low (1.17%). The results of this study indicate that selecting an appropriate carrier oil is important for the design of self-stabilized W/O Pickering emulsions to improve the bioaccessibility of betulin and other lipophilic bioactivities effectively. © 2024 Society of Chemical Industry.

A crystallinity control strategy for controllable Heterogeneous-Homogeneous reaction and catalytic performance in wet-mechanochemical synthesized FeS2 Fenton system

In heterogeneous Fenton system, the Heterogeneous-Homogeneous reaction type induced by surface-bonded or dissolved catalytic center plays a vital role in determining Fenton performance. However, how to directionally control the reaction type with facile method still remains challenging. Herein, a novel crystallinity control strategy based on wet-mechanochemical synthesis combined with heat-treatment was applied to synthesize FeS2 nanoparticles with different crystallinity. The different crystalline FeS2 based Fenton system exhibited superior sulfamethoxazole removal performance at wide pH range (5.6–11) with •OH as dominating reactive oxygen species. The relative degradation contribution of homogeneous and heterogeneous Fenton reaction was semi-quantitatively evaluated, and the relationship between crystallinity indexes of FeS2 and degradation kinetic constants was established. It’s found that FeS2 crystallinity was directly correlated with its degradation efficiency, which first increased and then declined with crystallinity increasing. Crystallinity control strategy effectively determined dominating reaction type (homogeneous or heterogeneous) and further regulated catalytic performance in FeS2 Fenton system based on the interaction of specific surface area and Fe2+ dissolution ability. This work provides a novel crystallinity control strategy to build a correlative bridge among crystallinity, dominating reaction type and catalytic performance in FeS2 Fenton system.

Hydrophobic deep eutectic solvents as novel media for the recycling of waste photovoltaic modules

Disposing of end-of-life photovoltaic (PV) modules has posed a significant environmental challenge due to the absence of proficient and sustainable recycling technologies. Separating PV modules, which are ethylene–vinyl acetate (EVA)-bonded layers, including glass, solar cells (i.e., silicon wafers), and backsheets, establishes a foundation for effectively reclaiming valuable resources from PV modules. Removing EVA encapsulation is critical for disassembling PV modules; nonetheless, effective and feasible technology is currently limited. Conventional EVA dissolving agents (e.g., benzene and trichloroethylene) are highly toxic and effective only for non-cross-linked segments of EVA. Thus, developing efficient and environmentally benign reagents for PV waste recycling is urgently needed. Herein, a novel recycling route employing deep eutectic solvents (DESs) with switchable hydrophilicity has achieved successful separation of the component layers within PV modules. Complete separation of the glass and backsheet bonded by the EVA film was achieved under atmospheric pressure and moderate temperature conditions (80 °C for 2 h) by hydrophobic DESs composed of menthol and decanoic acid ([Men][DecA] (1:1)). [Men][DecA] effectively induced EVA swelling, concurrently accelerating EVA dissolution by substituting the acetate groups in the side chains of EVA with the hydroxyl groups of the DES. The superior PV module disintegration can be attributed to the exceptional EVA dissolution ability of the [Men][DecA] framework, and the achieved high solid–liquid ratio (40 g/L) for EVA in [Men][DecA] is beneficial for industrial processes. Furthermore, the reusability of [Men][DecA], which is endorsed by its switchable hydrophilicity, introduces a sustainable platform for PV module disintegration, thereby facilitating the large-scale recycling of PV waste.

Correlation of dopant solution on doping mechanism and performance of F4TCNQ‐doped P3HT

AbstractUnderstanding the doping mechanism between the dopants and the conjugated polymers (CPs) is crucial for efficiently utilizing the doping process in a controllable manner. In this work, we doped the poly(3‐hexylthiophene) (P3HT) films with 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4TCNQ) from a chlorobenzene/acetonitrile (CB/AN) solvent blend and pure AN solvent by using the common sequential doping method. We found that the dissolution ability of the dopant solvent to P3HT and the concentration of the dopant solution were two critical factors to determine the doping process (solution doping or sequential doping) and the doping region (the amorphous or the crystalline phase). When the concentration of the dopant solution was low, solution doping was dominant in the P3HT film doped with F4TCNQ CB/AN solution, and the amorphous regions were doped in the P3HT film doped with F4TCNQ AN solution. With the increase of the dopant solution concentration, the ratio of ordered integer charge transfer (ICT) species, which formed from sequentially doped crystalline domains in the P3HT precast film, increased. Based on the above doping mechanism, a P3HT film with good electrical and tensile performance could be constructed by doping from F4TCNQ CB/AN solution with a relatively low concentration. Our work indicates that the dissolution or swelling ability of the dopant solvent to CP is an important factor in determining not only the doping mechanism but also the electrical and mechanical performances of doped CP films.

Task-specific design of protic metal-based deep eutectic solvents for efficient separation of HCl/SO2

Efficient separation and recovery of hydrogen chloride (HCl) from HCl tail gas containing impurities such as sulfur dioxide (SO2) is very important from the viewpoint of economy and environment. However, due to the similar dissolution ability of SO2 and HCl, most solvents, including organic solvents, ionic liquids and deep eutectic solvents (DESs), show low SO2/HCl selectivity near 1.0 and are thus incompetent to separate SO2/HCl. To address this, we firstly reported the task-specific design of a novel class of protic metal-based DESs (PM-DESs) containing hydrochloride, metal chloride and sulfolane, which have good SO2 affinity but much inhibited HCl uptake, for the separation of HCl/SO2. The solubility data of SO2 and HCl in PM-DESs were determined and correlated by Krichevsky-Пiinskaya (K-I) equation. Among these PM-DESs, N,N-dimethylaniline hydrochloride (DMA·HCl) + zinc chloride (ZnCl2) + sulfolane exhibits satisfactory recyclability and selectivity up to 2.669 (100 kPa, 313.2 K), which is the highest value reported so far. Absorption of HCl/SO2 (50/50) mixed gas was also tested, with a high SO2/HCl selectivity of 3.250 obtained. In addition, the NMR and FTIR spectroscopic characterizations paired with quantum chemistry calculation were utilized to investigate the absorption mechanism from the perspective of atomic level. The DESs developed in the present work have the potential to separate and recycle HCl from SO2 owing to their good selectivity and desirable reversibility, and the strategy proposed in this work may offer new guidance for designing green media for HCl recovery.

Tissue Dissolution Ability of Sodium Hypochlorite, EDTA, Ambroxol Hydrochloride and Triphala Evaluated and Compared when used as an Irrigant on Bovine Pulp Tissue

Aim: The aim of the study is to evaluate pulp tissue dissolution ability of Sodium hypochlorite (NaOCl), Ethylenediaminetetraacetate (EDTA), Ambroxol hydrochloride and Triphala.  Methods: Pulp tissue of BOS Taurus primigenius was extracted from 20 mandibular incisors of 4 bovine jaws .Decoronation was done at the cementum–enamel junction and roots were resected at a length of 3 mm from the apex with a diamond disc connected to a electric micromotor. Pulp tissue was then taken out of the pulp chamber of the bovine tooth with a periodontal probe and cotton pliers. Specimens were weighed using a hermetic precision electronic balance (AND Company LTD) before the test to analyze the initial weight (T0) of the samples. Extracted bovine pulp tissue specimens were weighed and randomly distributed in to 4 experimental groups of 3% sodium hypochlorite, 17% EDTA, Ambroxol hydrochloride(35mg/ml), Triphala(100mg/ml) that were taken in 4 centrifugation tubes. Contents are filtered and undissolved tissue remnants collected and reweighed.  Results: Results obtained indicate that highest pulp dissolution is for NaOCl, followed by EDTA, Ambroxol Hydrochloride and least for Triphala.  Conclusion: Highest pulp dissolution is for NaOCl, followed by EDTA, Ambroxol Hydrochloride and least for Triphala.

Development and optimization of the Glabridin-loaded dissolving microneedle for enhanced treatment of keloid

Glabridin (Gla) has been reported to have significant effects in scar treatment, and however, the water insolubility of Gla leads to its poor transdermal absorption ability, which affects its bioactivities. Therefore, we attempted to prepare the Gla dissolving microneedles (Gla-MN) to improve the absorbtion of Gla. After investigation of the 3 factors including the needle tip matrix concentration, the prescription concentration of backing material, and the dissolution method of Gla, we finally determined the process parameters of 10% hyaluronic acid (HA) as the needle tip and 5% polyvinyl alcohol (PVA) as the backing, according to which the Gla-MN was prepared with the good characteristics of high hardness, complete appearance and good in vitro dissolution ability. We then loaded Gla onto the microneedles and measured that the average drug loading of Gla-MN was 2.26 ± 0.11 μg/mg and the cumulative transdermal release of Gla-MN was up to 76.9% after 24 h. In addition, Gla-MN had good skin penetration properties, with Gla-MN penetrating at least 4 to 5 layers of parafilm. And the skin basically could return to normal after 4 h of piercing. Importantly, our results showed that Gla-MN had higher transdermal delivery and therapeutic effects against keloid than that of Gla at the same dosage.

Does increase in temperature of sodium hypochlorite have enhanced antimicrobial efficacy and tissue dissolution property? - A systematic review and meta-regression.

The objective of this study was to analyze the available evidence on the performance of increase in temperature of sodium hypochlorite on its antimicrobial efficacy and tissue dissolution property. The study was conducted according to PRISMA guidelines, and a modified Joanna Briggs Institute (JBI) tool was used for quality assessment of the included studies. Two reviewers independently performed an electronic search in four databases along with the reference lists of the included articles. This systematic review included a total of 12 studies: antimicrobial efficacy (n = 6) and tissue dissolution property (n = 6). For the studies that were chosen, the overall risk of bias was moderate. Quantitative assessment through meta-regression was performed for tissue dissolution property. Low-concentration sodium hypochlorite irrigant (≤3%) shows a 0.13-unit times increase in tissue dissolution ability with a degree rise in temperature although not statistically significant. Due to inconsistency in the study parameters, results pertaining to the exclusive effect of increase in the temperature of sodium hypochlorite remain inconclusive.

Comparative Analysis of Various Irrigation Solutions in Root Canal Treatment.

"Root canal treatment (RCT)" is essential in preserving natural dentition by eliminating infection within the root canal system. Irrigation solutions play a crucial role in achieving successful RCT outcomes by facilitating disinfection and debris removal. An in vitro experimental design was employed to evaluate the irrigation solutions. Antimicrobial efficacy was assessed using agar diffusion assays against Enterococcus faecalis and Candida albicans. Tissue dissolution ability was evaluated by measuring the weight loss of dentin specimens. Cytotoxicity was assessed using cell viability assays with human periodontal ligament fibroblasts. NaOCl demonstrated the highest antimicrobial efficacy, while EDTA exhibited superior tissue dissolution ability. CHX and QMix displayed lower cytotoxicity compared to NaOCl and EDTA. The choice of irrigation solution in RCT should consider factors such as antimicrobial efficacy, tissue dissolution ability, and cytotoxicity. NaOCl remains effective but has high cytotoxicity, whereas CHX and QMix offer alternatives with lower cytotoxicity. EDTA is effective in tissue dissolution but should be used cautiously due to cytotoxic potential. Clinicians should weigh the benefits and limitations of each solution for optimal treatment outcomes.

Sugar-Based Surfactants: Effects of Structural Features on the Physicochemical Properties of Sugar Esters and Their Comparison to Commercial Octyl Glycosides.

Two series of sugar esters with alkyl chain lengths varying from 5 to 12 carbon atoms, and with a head group consisting of glucose or galactose moieties, were synthesized. Equilibrium surface tension isotherms were measured, yielding critical micellar concentration (CMC) surface tensions at CMC (γcmc) and minimum areas at the air-water interface (Amin). In addition, Krafft temperatures (Tks) were measured to characterize the ability of molecules to dissolve in water, which is essential in numerous applications. As a comparison to widely used commercial sugar-based surfactants, those measurements were also carried out for four octyl d-glycosides. Impacts of the linkages between polar and lipophilic moieties, alkyl chain lengths, and the nature of the sugar head group on the measured properties were highlighted. Higher Tk and, thus, lower dissolution ability, were found for methyl 6-O-acyl-d-glucopyranosides. CMC and γcmc decreased with the alkyl chain lengths in both cases, but Amin did not appear to be influenced. Both γcmc and Amin appeared independent of the ester group orientation. Notably, alkyl (methyl α-d-glucopyranosid)uronates were found to result in noticeably lower CMC, possibly due to a closer distance between the carbonyl function and the head group.

Nanosuspension-Loaded Dissolving Microneedle Patches for Enhanced Transdermal Delivery of a Highly Lipophilic Cannabidiol.

Transdermal Drug Delivery System (TDDS) offers a promising alternative for delivering poorly soluble drugs, challenged by the stratum corneum's barrier effect, which restricts the pool of drug candidates suitable for TDDS. This study aims to establish a delivery platform specifically for highly lipophilic drugs requiring high doses (log P > 5, dose > 10 mg/kg/d), to improve their intradermal delivery and enhance solubility. Cannabidiol (CBD, log P = 5.91) served as the model drug. A CBD nanosuspension (CBD-NS) was prepared using a bottom-up method. The particle size, polydispersity index (PDI), zeta potential, and concentration of the CBD-NS were characterized. Subsequently, CBD-NS was incorporated into dissolving microneedles (DMNs) through a one-step manufacturing process. The intradermal dissolution abilities, physicochemical properties, mechanical strength, insertion depth, and release behavior of the DMNs were evaluated. Sprague-Dawley (SD) rats were utilized to assess the efficacy of the DMN patch in treating knee synovitis and to analyze its skin permeation kinetics and pharmacokinetic performance. The CBD-NS, stabilized with Tween 80, exhibited a particle size of 166.83 ± 3.33 nm, a PDI of 0.21 ± 0.07, and a concentration of 46.11 ± 0.52 mg/mL. The DMN loaded with CBD-NS demonstrated favorable intradermal dissolution and mechanical properties. It effectively increased the delivery of CBD into the skin, extended the action's duration in vivo, and enhanced bioavailability. CBD-NS DMN exhibited superior therapeutic efficacy and safety in a rat model of knee synovitis, significantly inhibiting TNF-α and IL-1β compared with the methotrexate subcutaneous injection method. NS technology effectively enhances the solubility of the poorly soluble drug CBD, while DMN facilitates penetration, extends the duration of action in vivo, and improves bioavailability. Furthermore, CBD has shown promising therapeutic outcomes in treating knee synovitis. This innovative drug delivery system is expected to offer a more efficient solution for the administration of highly lipophilic drugs akin to CBD, thereby facilitating high-dose administration.

Molecular modification of low-dissolution soy protein isolates by anionic xanthan gum, neutral guar gum, or neutral konjac glucomannan to improve the protein dissolution and stabilize fish oil emulsion

Herein, the effects of anionic xanthan gum (XG), neutral guar gum (GG), and neutral konjac glucomannan (KGM) on the dissolution, physicochemical properties, and emulsion stabilization ability of soy protein isolate (SPI)-polysaccharide conjugates were studied. The SPI-polysaccharide conjugates had better water dissolution than the insoluble SPI. Compared with SPI, SPI-polysaccharide conjugates had lower β-sheet (39.6 %–56.4 % vs. 47.3 %) and α-helix (13.0 %–13.2 % vs. 22.6 %) percentages, and higher β-turn (23.8 %–26.5 % vs. 11.0 %) percentages. The creaming stability of SPI-polysaccharide conjugate-stabilized fish oil-loaded emulsions mainly depended on polysaccharide type: SPI-XG (Creaming index: 0) > SPI-GG (Creaming index: 8.1 %–21.2 %) > SPI-KGM (18.1 %–40.4 %). In addition, it also depended on the SPI preparation concentrations, glycation times, and glycation pH. The modification by anionic XG induced no obvious emulsion creaming even after 14-day storage, which suggested that anionic polysaccharide might be the best polysaccharide to modify SPI for emulsion stabilization. This work provided useful information to modify insoluble proteins by polysaccharides for potential application.