Solid Surfactant Research Articles

An organic-based amphiphilic Janus polymer nanosheet: Synthesis, properties, and microscopic dispersion interpretations

Due to the distinctive anisotropy in shapes and affluent potential in properties, amphiphilic Janus polymer nanosheets (AJPN) have attracted widespread attention. Low-cost, controllable, and precise functional polymerization remains a great challenge to conventional template methods. Herein, an organic-based AJPN was synthesized with polystyrene as the hydrophobic side and carboxyl groups presented at the hydrophilic side. Sucrose was selected as the adsorption template, which could be removed simply by water-washing. The lateral sizes could be regulated by adjusting the ultrasonic time and power after the precise construction of polymer shells. The colloidal stability and aggregation kinetics of AJPN suspension under different conditions were quantitatively measured. In particular, Rheolaser optical microrheology was pioneered to explore the authentic migration behaviors and rheological properties of AJPN aqueous solution for the first time. The results revealed that AJPN solution presented as thermodynamically unstable solid suspension, which was far different from real solution, emulsion or cross-linked hydrogel formed by common hydrophilic polymers. The carboxyl groups and the steric effect of polymer chains greatly improved the self-stability of AJPN suspension. The influences of microscopic migration of AJPN on their macroscopic dispersion in different stages were concluded, which was closely related to the applicability of nanofluid products in storage, transportation, or performance periods. Moreover, due to the amphiphilic property, Janus nature and lamellar nanomorphology, AJPN could be used as solid surfactants to reduce oil–water interfacial tension and stabilize emulsions. We hope this work can offer more opportunities for the synthesis of AJPN with different chemical compositions, and promote the development of dispersion stability of nanosheets.

Cilostazol-loaded solid lipid nanoparticles: Bioavailability and safety evaluation in an animal model

Cilostazol (CLZ) is an antiplatelet agent with limited solubility (∼6 μg/ml at 25 °C), poor absorption and low oral bioavailability. In this study, solid lipid nanoparticles (SLNs) were used as a drug delivery system to improve the CLZ dissolution, absorption and bioavailability. Micro-emulsion method was used to fabricate CLZ-loaded SLNs. The SLNs were composed of palmityl alcohol, Tween® 80, and Span® 40 as solid lipid, surfactant, and co-surfactant, respectively. Additionally, Myrj 52 was used as a steric stabiliser. The SLNs were characterised in terms of particle size, zeta potential, polydispersity index (PDI), and incorporation efficiency (IE). Transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and Fourier transform infrared (FTIR) spectroscopy were also performed. In vitro release and pharmacokinetic studies were carried out, followed by evaluation of the safety and stability of the formulated SLNs. Optimised CLZ-loaded SLNs showed a spherical morphology with particle sizes below 200 nm, with excellent PDI (0.18), zeta potential (−29.7 mV), and %IE (92%). FTIR and PXRD studies indicated no chemical interaction between the constituents of the SLNs and the conversion of crystalline form of drug to amorphous form, respectively. CLZ-loaded SLNs demonstrated a significantly enhanced release (p < 0.05) and meaningfully improved bioavailability (p < 0.05) as compared with the CLZ suspension. Histopathological evaluation showed that CLZ-loaded SLNs were nontoxic to the cells lining the intestinal tract. They were found to have a stable shelf life during the three-month evaluation period. Hence, it was concluded that CLZ-loaded SLNs have the potential to improve the oral bioavailability of CLZ without toxicity.

NANOSTRUCTURED LIPID CARRIERS FOR TRANSDERMAL DRUG DELIVERY

Transdermal drug delivery offers many advantages over oral delivery, such as avoiding first-pass metabolism, enhancing the bioavailability of poorly soluble drugs, and providing better patient compliance. However, only small lipophilic molecules can be delivered across the stratum corneum, the outermost layer of the skin. Unfortunately, the delivery of larger molecules remains a challenge. Nanostructured lipid carriers (NLCs) are second-generation lipid nanocarriers composed of biocompatible solid lipids, liquid lipids, surfactants, and co-surfactants. NLCs can be loaded with various classes of drugs, provide a controlled drug release profile, enhance drug stability, and be scaled up without needing organic solvents. This review article discusses the features, composition, formulation processes, and characterization of NLCs and their potential use in transdermal drug delivery.

Fabrication of Janus-type nanocomposites from cellulose nanocrystals for self-healing hydrogels’ flexible sensors

Janus bio-nanomaterials have great application potential in functional solid surfactants, probes and flexible sensors. In this manuscript, the sustainable Janus cellulose nanocrystals-type (CNCs-type) nanomaterials were prepared by Pickering emulsion template method. The asymmetric functionalism of Janus nanorods was realized by asymmetrically grafting polypyrrole (PPy) and polydopamine (PDA) onto different sides of CNCs (Janus CNCs-PPy /PDA (JCNs)). JCNs was successfully applied to self-healing nanocomposite hydrogels and further applied to the development of flexible sensors. The self-healing efficiency of nanocomposite hydrogels was 87.2%, and the stress and strain reached 3.50 MPa and 453.45%, respectively. It is worth noting that flexible sensors have been widely used in the field of wearable electronic sensing for real-time monitoring of human movement due to their high sensitivity (gauge factor (GF) = 9.9) and fast response time (260 ms).

Systematic Development of Solid Lipid Nanoparticles of Abiraterone Acetate with Improved Oral Bioavailability and Anticancer Activity for Prostate Carcinoma Treatment.

In the present work, an attempt was undertaken to improve the oral bioavailability and anticancer activity of abiraterone acetate. Solid lipid nanoparticles (SLNs) were developed using the quality by design (QbD) principles and evaluated through in vitro, ex vivo, and in vivo studies. Solid lipid suitability was evaluated by equilibrium solubility study, while surfactant and cosurfactant were screened based on the ability to form microemulsion with the selected lipid. SLNs were prepared by emulsion/solvent evaporation method using glyceryl monostearate, Tween 80, and Poloxamer 407 as the solid lipid, surfactant, and cosurfactant, respectively. Box-Behnken design was applied for optimization of material attributes and evaluating their impact on particle size, polydispersity index, zeta potential, and entrapment efficiency of the SLNs. In vitro drug release study was evaluated in simulated gastric and intestinal fluids. Cell culture studies on PC-3 cells were performed to evaluate the cytotoxicity of the drug-loaded SLNs in comparison to the free drug suspension. Qualitative uptake was evaluated for Rhodamine B-loaded SLNs and compared with free dye solution. Ex vivo permeability was evaluated on Wistar rat intestine and in vivo pharmacokinetic evaluation on Wistar rats for SLNs and free drug suspension. Concisely, the SLNs showed potential for significant improvement in the biopharmaceutical performance of the selected drug candidate over the existing formulations of abiraterone acetate.

Design and optimization of myricetin encapsulated nanostructured lipid carriers: In-vivo assessment against cognitive impairment in amyloid beta (1–42) intoxicated rats

AimsThis research aimed to evaluate the potential of MY loaded nanostructured lipid carrier (MY-NLCs) to ameliorate the bioavailability in the brain and cognitive impairment in Aβ induced Alzheimer’'s model. Materials and MethodsMY-NLCs were prepared with precirol ATO 5, labrafac lipophile WL 1349, and tween 80 as solid lipid, liquid lipid, and surfactant respectively. The formulation was optimized with central composite design (CCD) and characterized by different parameters. Cellular toxicity and uptake studies were evaluated in SH-SY5Y cells. MY concentration in plasma and brain was analyzed after the i.p. administration of MYS and MY-NLCs (40 mg/kg) in Sprague–Dawley rats (n = 3). Further, the pharmacodynamic studies were evaluated in the (Aβ1‐–42) induced (5 μg/5 μl, ICV, unilateral) Alzheimer’'s rat model (n = 6) and cognitive performance was assessed using Morris water maze test followed by histological and neurotransmitters analyses in rats’' brain. Key findingsThe optimized MY-NLCs exhibited 89.7 ± 26.0 nm particle size, 80.81 ± 10.39% entrapment efficiency, and 5.08 ± 1.0% of drug loading capacity. The in-vitro release studies revealed a biphasic release pattern and also demonstrated distinct cellular internalization in SH-SY5Y cells. MY-NLCs exhibited 2.77 folds higher AUC 0–24 in plasma and drug targeting efficiency for MY into the brain was found 127.05% as compared to MYS. The mitigating potential of MY-NLCs (10 mg/kg) was also significantly observed in behavioral parameters and in the regulation of neurotransmitters levels in rat brain. SignificanceMY-NLCs would be explored as an alternative promising drug delivery platform for several neurodegenerative payloads.

Enhancement in nickel-silica interface generation by surfactant-assisted melt-infiltration: Surfactant selection and application in CO2 hydrogenation

Effective nickel-based catalysts used in CO2 methanation require high loadings (∼40 wt%) of nanoscale (∼10 nm) nickel particles. However, particle loading and size are inversely proportional. Surfactant-assisted melt-infiltration (SAMI) may alleviate this problem. In this study, various solid surfactants (Span60, SDBS, and CTAB) were homogeneously mixed with nickel nitrate and mesoporous silica support (SBA-15) under non-solvent conditions during melt-infiltration. The non-ionic surfactant (Span60) afforded a high loading (40 wt%) of nanoscale (11 nm) nickel particles and generated a large number of interfaces between the nickel particles and the support. These interfaces may contain oxygen vacancies that facilitate the adsorption–dissociation of CO2 on the catalyst surface. The Span60/40Ni/as-syn-SBA-15 catalyst exhibited the highest catalytic activity with CO2 conversion of 78 % and CH4 selectivity of 99 % at a temperature of 350 ℃ (Space Velocity: 120,000 mL/ gcat·h). The nanoscale size of the catalyst improved the catalytic performance by ensuring a simple and efficient reaction pathway. The SAMI method generates no liquid waste and may be commercialized to produce efficient catalysts.

Empowering alkali lignin with high performance in pickering emulsion by selective phenolation for the protection and controlled-release of agrochemical

Lignin is a versatile bioaromatic polymer, with great potentials in the preparation of advanced materials due to its anti-UV and anti-oxidant properties. However, the high heterogeneity of lignin seriously hinders its practical applications. In this study, alkali lignin with limited content of hydroxyl groups and a wide distribution of molecular weight was modified by selective phenolation, which not only resulted in a dramatical increase in the content of phenolic hydroxyl groups but also led to a more uniform structure of lignin. Catechol, as compared with phenol and pyrogallol, was the most suitable phenolation reagent to reacted with lignin, and the phenolic hydroxyl content of the catechol modified lignin increased by 318.89%. Besides, the molecular weight and polydispersity index of lignin after the modification decreased, which led to a small and regular size of lignin particles prepared by acid precipitation. Subseqently, lignin particles were used to prepare Pickering emulsions for avermectin (AVM) encapsulation, and the stability as well as the anti-UV and anti-oxidant capacities of Pickering emulsions prepared by using phenolated lignins as solid surfactants were obviously enhanced. The encapsulation efficiency of AVM in Pickering emulsions was also improved, which could reach high above 90%. Moreover, AVM protected by lignin-based Pickering emulsion could be controllably released in line with actual application demands, and the relatively high viscosity of emulsion could effectively avoid the loss of pesticide during spraying to the target.

Tailored synthesis of molecularly thin platinum nanosheets using designed 2D surfactant solids.

The assembly of the surfactants has been utilized as unique templates for the controlled synthesis of metal nanosheets. However, current strategies for metal nanosheets have mainly focused on the liquid-phase surfactant assembly. Herein, we found the solid-state surfactants as designable crystals suitable for nanostructural control and proposed a novel synthetic route for molecularly thin Pt metal nanosheets using solid surfactant crystals as a precursor. The 2D surfactant crystals containing planarly arranged Pt complexes were prepared, and the subsequent UV-ozone treatment and reduction process allowed us to obtain Pt metal nanosheets. Pt metal nanosheets had a distinct morphology with various thicknesses (from 1.5 nm to 3.0 nm), characteristic of 2D surfactant crystals.

Molecular dynamics study on vibration-mode matching in surfactant-mediated thermal transport at solid–liquid interfaces

Surfactants have attracted attention as a means of enhancing thermal transport across solid–liquid interfaces. In the present study, non-equilibrium molecular dynamics simulation was used to study the effect of surfactants on interfacial thermal transport at solid–liquid interfaces, from the viewpoint of vibration-mode matching. The solid atom, surfactant molecule, and solvent molecule were all represented by a single atom. The vibrational characteristics of surfactant molecules were altered by changing surfactant mass msrf, surfactant concentration csrf, and the interaction strength between solid atoms and surfactant molecules, εsld–srf. For given values of csrf and εsld–srf, the interfacial thermal resistance (ITR) between the solid and surfactant solution exhibited a minimum as a function of msrf. This minimum was found to result from the mutual interference of interparticle heat transfer among atoms in the solid surface layer, and surfactant and solvent molecules in the first and second adsorption liquid layers. The amount of interparticle heat transfer was only partly correlated with the traditionally used overlap of vibrational density of states and with the matching of the characteristic frequencies associated with the spring constant of potential of mean force, proposed here. From this result, we conclude that ITR at solid–liquid interfaces can be minimized by optimizing the vibrational characteristics of surfactant molecules, but the theory of vibration-mode matching should be refined in order to fully identify the condition under which the best vibrational matching occurs between solid, surfactant, and solvent.

Solid lipid nanoparticles and nanoemulsions with solid shell: Physical and thermal stability

HypothesisNanoemulsions (NE) and solid lipid nanoparticles (SLN) used for drug delivery should have a solid shell to be stable during long shelf life and become liquid at human body temperature. The core components of lipid nanoparticles can be partially incorporated into the shell and affect the physical and thermal stability. ExperimentsWe prepared NE and SLN by the phase inversion temperature (PIT) method. Solidification of the surfactants Tween60 and Span 60 on the surface of NE droplets with paraffin oil resulted in the formation of the solid shell. SLN contained stearic acid in the core and the same surfactants in the solid shell. The size, structure and stability of the NE and SLN were studied by DLS and cryo-TEM. Their crystallization and melting were analyzed using DSC. FindingsThe lipid nanoparticles were resistant to aggregation and sedimentation and hold up to at least two cycles of heating to 50–60 °C and subsequent cooling to 5 °C, even though the upper temperatures were higher than the melting point of the surfactant shell. The expected liquid core/solid shell morphology of NE was confirmed. SLN were composed of a semi-liquid core of supercooled stearic acid melt and coated with a solid surfactant shell, so they can be treated as NE. Stearic acid molecules penetrated the shell, leading to an increase in its melting point.

Solid nanostructured lipid carriers loaded with silymarin for oral delivery: Formulation development and evaluation

The present study was aimed at preparing stable dry adsorbed nanoparticles (DANs) of silymarin loaded nanostructured lipid carriers (NLCs). The prepared silymarin loaded NLCs and DANs were characterized for various quality parameters. Silymarin loaded NLCs were prepared by a modified hot melt emulsification ultra-sonication method using glyceryl monostearate (GMS), capmul MCM C8 EP (CAP) and gelucire 50/13 (G50/13) as solid lipid, liquid lipid and surfactant respectively. For better stability, NLC dispersion was converted into DANs by adsorbing them onto some suitable carriers. NLCs and DANs were characterized for particle size, polydispersity index, zeta potential, entrapment efficiency, drug loading, assay, thermal behavior, crystallinity and morphological study. The optimized NLCs have a mean particle size of 206.1±012.5 nm (size distribution of 0.249±0.058), a zeta potential of -32.5±1.2 mV with high entrapment of 95.60±0.45% and drug loading of 1.90±0.08%. The X-ray diffraction and endothermic peaks confirmed the maximum encapsulation of active in lipid matrices. The particles were spherical with smooth surface morphology. In-vitro release studies showed sustained drug release for up to 24 h. Ex-vivo permeation in the presence and absence of lymphatic blocker indicates the uptake of silymarin loaded NLCs by the lymphatic route. Silymarin loaded NLCs prepared had a nanosize distribution with high entrapment efficiency. The ex-vivo permeation study for optimized NLC formulation exhibited the lymphatic uptake of active. Dispersion stability was increased by preparing the DANs. The solid dry powder is used for oral reconstitution and can be further converted into tablets or filled into capsules.

Magnetic cluster-encapsulated polymer dimers with controlled surface property

This work reports the fabrication of magnetic polymer dimers with controlled surface anisotropy. The fabrication process involves the preparation of magnetite (Fe3O4) magnetic clusters with strong magnetism, followed by their surface modification, dispersion polymerization while using them as seeds, multilayer shell formation via layer-by-layer deposition, and polymer core swelling. The interplay between the swelling and multilayer shells generates pressure inside the multilayer-deposited, magnetic polystyrene (PS) spheres, forming structurally anisotropic dimers with single PS protrusions anchored on the multilayer surfaces within minutes. The use of titania precursor and different swelling agents, along with the change in the composition of the multilayer shell, enables the introduction of different surface anisotropies, such as the surface-charge anisotropy, anisotropic hydrophilicity/hydrophobicity, and material composition anisotropy, to the dimers. The strong magnetic response of the dimers, attributed to the magnetic cluster seeds, in combination with the surface-charge and material composition anisotropies allows a rapid magnetic recovery and an excellent reusability, enabling their application to 20-cycled reduction of 4-nitrophenol (4-NP) and methylene blue (MB) without loss of catalytic activity. Furthermore, the anisotropic hydrophilicity/hydrophobicity makes the dimers potentially useful as solid surfactant to stabilize immiscible oil–water mixture.

Preparation of Nanostructured Lipid Carriers (NLCs) Loading Violacein Extract for Anti-Acne Products

The objective of this research is to evaluate the antimicrobial activity of Nanostructured Lipid Carriers (NLCs) loading violacein extract. The extract was tested for the antimicrobial activities against 3 strains of pathogenic bacteria; namely Cutibacterium acnes ATCC 6919, Staphylococcus aureus ATCC 6538 and Staphylococcus epidermidis ATCC 12228 by agar well diffusion assay. The result indicated that the violacein extract from Chromobacterium violaceum ATCC 12472 has strongest antibacterial effect against C. acnes, S. aureus and S. epidermidis with MIC values in range of 0.0146-0.4688 mg/mL with the lowest MBC value of 0.0146 mg/mL against C. acnes. Violacein extract loaded Nanostructured Lipid Carriers (NLCs) for anti-acne products were prepared by using melt-emulsification technique. The studied factors are the ratio of liquid lipid and solid lipid (LL:SL), surfactant concentration and sonication time. The Ratio of Oleic acid and Compritol® 888 ATO (3:1) with Tween 20 (1.5% w/w) and sonication time of 10 minute (F8 formulation) are an optimizing condition for NLC-Base. The resulted formulations showed the NLC-Base had average particle size of 213.7±2.42 nm with a polydispersity index of 0.239±0.003 and Zeta potential of -26.6±0.45 mV. After that, violacein extract (2% w/w) was loaded into the NLCs (VIO-NLCs). Antibacterial activity of VIO-NLCs 2 % was determined by using agar dilution. The result showed that VIO-NLCs 2 % can inhibit the growth of C. acnes for 60 days during storage. Furthermore, VIO-NLCs 2 % can also act as S. aureus and S. epidermidis inhibitor within 30 days shelf life.

Berberine loaded nanostructured lipid carrier for Alzheimer's disease: Design, statistical optimization and enhanced in vivo performance

Berberine, an isoquinoline alkaloid, is reported for the treatment of Alzheimer's disease. Despite having substantial therapeutic potential, it exhibits poor absorption, low oral bioavailability and limited penetration in the brain. In this study, berberine-loaded nanostructured lipid carriers (Berb-NLCs) were developed by melt-emulsification and ultrasonication using Geleol, Miglyol 812 N, Solutol HS 15 as a solid lipid, liquid lipid and surfactant, respectively. The Berb-NLC formulation was statistically optimized by a 32 factorial design in which the effect of surfactant and berberine concentration was assessed on particle size and entrapment efficiency of Berb-NLCs. Optimized Berb-NLCs (Trial-5) exhibited particle size of 186 nm, polydispersity index of 0.108, the zeta potential of -36.86 mV and 88% entrapment efficiency. The in vitro release of berberine from Batch-B5 was 82% in phosphate buffer at the end of 24 h. The comparative results of pharmacodynamic studies involving behavioral assessment by locomotor activity, passive avoidance test, elevated plus maze test and spatial memory assessment by Morris water maze demonstrated improved behavioral parameters in vivo by Berb-NLCs compared to pure berberine in Albino Wistar rats. Thus, berberine-loaded nanostructured lipid carriers have the potential of brain targeting and were effective in an animal model of Alzheimer's disease.

Fig seed oil‐loaded nanostructured lipid carriers: Evaluation of the protective effects against oxidation

The aim of this study was to develop a carrier system that protects fig seed oil (FSO) from oxidation by encapsulating into nanostructured lipid carriers (NLCs). NLCs were prepared by high shear mixing technique and the effects of solid lipids and surfactants on the formulation parameters were investigated. The formulations were characterized in terms of particle size, polydispersity index, and zeta potential, and fatty acid and tocopherol amounts were determined by GC and HPLC, respectively. NLC loaded with FSO was obtained at a particle size of 241 nm with low polydispersity (0.259) and a negative electrical charge (−13.6 mV). The antioxidant capacity has been evaluated by accelerated oxidation storage tests, radical and hydrogen peroxide scavenging activity tests. The stability of the final formulation with high concentration of gamma tocopherol and unsaturated linoleic acid content of FSO was increased by loading into NLCs. Novelty impact statement NLC formulations loaded with FSO were prepared for the first time at a dimension of 241 nm with low polydispersity. FSO was protected against lipid oxidation by encapsulation into NLC as revealed by lipid peroxidation, hydrogen peroxide, and radical scavenging activity tests. FSO-loaded NLC formulations were shown to be valuable carriers for encapsulation of bioactive food materials for stability.

Formulation and Optimization of Butenafine-Loaded Topical Nano Lipid Carrier-Based Gel: Characterization, Irritation Study, and Anti-Fungal Activity.

The present study aims to prepare and optimize butenafine hydrochloride NLCs formulation using solid and liquid lipid. The optimized selected BF-NLCopt was further converted into Carbopol-based gel for topical application for the treatment of fungal infection. Box Behnken design was employed to optimize the nanostructure lipids carriers (NLCs) using the lipid content (A), Tween 80 (B), and homogenization cycle (C) as formulation factors at three levels. Their effects were observed on the particle size (Y1) and entrapment efficiency (Y2). The selected formulation was converted into gel and further assessed for gel characterization, drug release, anti-fungal study, irritation study, and stability study. The solid lipid (Compritol 888 ATO), liquid lipid (Labrasol), and surfactant (tween 80) were selected based on maximum solubility. The optimization result showed a particle size of 111 nm with high entrapment efficiency of 86.35% for BF-NLCopt. The optimized BF-NLCopt converted to gel (1% w/v, Carbopol 934) and showed ideal gel evaluation results (drug content 99.45 ± 2.11, pH 6.5 ± 0.2, viscosity 519 ± 1.43 CPs). The drug release study result depicted a prolonged drug release (65.09 ± 4.37%) with high drug permeation 641.37 ± 46.59 µg (32.07 ± 2.32%) than BF conventional gel. The low value of irritation score (0.17) exhibited negligible irritation on the skin after application. The anti-fungal result showed greater efficacy than the BF gel at both time points. The overall conclusion of the results revealed NLCs-based gel of BF as an ideal delivery system to treat the fungal infection.

Synthesis of Polymer Janus Particles with Tunable Wettability Profiles as Potent Solid Surfactants to Promote Gas Delivery in Aqueous Reaction Media.

Janus particles exhibit a strong tendency to directionally assemble and segregate to interfaces and thus offer advantages as colloidal analogues of molecular surfactants to improve the stability of multiphasic mixtures. Investigation and application of the unique adsorption properties require synthetic procedures that enable careful design and reliable control over the particles’ asymmetric chemistry and wettability profiles with high morphological uniformity across a sample. Herein, we report on a novel one-step synthetic approach for the generation of amphiphilic polymer Janus particles with highly uniform and tunable wettability contrasts, which is based on using reconfigurable bi-phasic Janus emulsions as versatile particle scaffolds. Two phase-separated acrylate oils were used as the constituent droplet phases and transformed into their solidified Janus particle replicas via UV-induced radical polymerization. Using Janus emulsions as particle precursors offers the advantage that their internal droplet geometry can be fine-tuned by changing the force balance of surface tensions acting at the individual interfaces via surfactants or the volume ratio of the constituent phases. In addition, preassembled functional surfactants at the droplet interfaces can be locked in position upon polymerization, which enables both access toward postfunctionalization reaction schemes and the generation of highly uniform Janus particles with adjustable wettability profiles. Depending on the particle morphology and wettability, their interfacial position can be adjusted, which allows us to stabilize either air bubbles-in-water or water droplets-in-air (liquid marbles). Motivated by the interfacial activity of the particles and particularly the longevity of the resulting particle-stabilized air-in-water bubbles, we explored their ability to promote the delivery of oxygen inside a liquid-phase reaction medium, namely, for the heterogeneous Au-NP-mediated catalytic oxidation of d-glucose. We observed a 2.2-fold increase in the reaction rate attributed to the increase of the local concentration of oxygen around catalysts, thus showcasing a new strategy to overcome the limited solubility of gases in aqueous reaction media.

Topical Delivery of Apremilast Loaded Nanostructured Lipid Carrier Based Hydrogel for Psoriasis Therapy

Background: Apremilast (APR) is an orally administered selective phosphodiesterase 4 inhibitor approved to treat plaque psoriasis and psoriatic arthritis and is available as an oral tablet formulation. However, its systemic side effects limit its application. The low solubility and permeability of apremilast make it difficult to administer it through the skin. Hence an attempt is made to incorporate apremilast into a suitable nanocarrier to facilitate its topical delivery.&#x0D; Aims: To formulate and characterize Apremilast loaded nanostructured lipid carriers for the management of psoriasis to reduce the systemic side effects.&#x0D; Methodology: Apremilast loaded Nanostructured Lipid carriers (NLC) were prepared by melt emulsification accompanied by probe sonication. The formulation was prepared using GMS, Sefsol 218, Tween 80 and Transcutol P as Solid Lipid, Liquid lipid, Surfactant and Penetration Enhancer. The NLC was incorporated into carbapol 934 dispersion to convert it into a gel. The NLC formulation was evaluated for size, Polydispersity Index, Zeta Potential, Entrapment efficiency, Transmission Electron Microscopy. After that, the NLC gel was examined for Spreadability, Extrudabilty, Viscosity, In vitro drug release, Ex vivo permeation, Skin deposition and In vivo studies.&#x0D; Results: The formulated Apremilast loaded showed particle size of less than 200 nm (i.e.170.32nm) with a narrow PDI of 0.267. Entrapment efficiency revealed that 89.26±01.22% of the drug was entrapped. Transmission electron microscopy images confirmed the spherical nature of the nanocarrier. The extended-release pattern of the formulated NLC for 24h was observed in the in vitro release studies and followed the Higuchi model(R2=0.9966). Ex vivo permeability showed a 6.14 fold increase in permeability and 74.05±0.25% deposition of apremilast loaded NLC gel compared to apremilast gel. The formulation was stable for three months without significant changes. In vivo skin studies showed that the prepared NLC did not have any skin irritation potential. The antipsoriatic activity demonstrated by the Apremilast loaded NLC gel in the imiquimod induced psoriasis model in mice was comparable to the standard treatment.&#x0D; Conclusion: Apremilast loaded NLC demonstrated enhanced permeation, improved skin retention and extended-release compared to conventional gel. The developed formulation can be an alternative for psoriasis therapy after clinical trials in the future.

Formulation and Optimization of Nano Lipid Based Oral Delivery Systems for Arthritis

Rheumatoid arthritis is an autoimmune disease characterized by chronic synovitis that leads to tissue dysfunction as well as loss of complete function. There are several synthetic NSAIDs, glucocorticoids and biological drugs that are commonly used to treat arthritis. These drugs have severe life-threatening side effects. The use of a bioactive compound (Apigenin) could be an alternative to synthetic conventional delivery systems. It is a poorly water-soluble drug having a wide range of pharmacological activities. It has been reported for potential anti-inflammatory and anti-arthritic activity. In the present study, Apigenin (APG) solid lipid nanoparticles were prepared using the solid lipid (glyceryl mono stearate, GMS), surfactant (d -α-Tocopheryl polyethylene glycol 1000 succinate, TPGS) and sonication time (ST). The optimized APG SLNs showed a particle size of 161.7 nm and encapsulation efficiency of 80.44 ± 4.11%. It was further coated with 0.1% w/v chitosan (APG-CH-SLNs) and showed the particle size, PDI and zeta potential of 185.4 nm, 0.45 + 26.7 mV, respectively. The significant (p &lt; 0.001) enhancement in drug release, permeation and mucoadhesive study was observed after chitosan coating. The antioxidant study results depicted an increase in antioxidant property. Finally, the anti-arthritic biochemical parameters revealed marked changes in the results in comparison to arthritic control animals. From the study, it was concluded that APG-loaded mucoadhesive lipid nanoparticles are an alternative to the synthetic oral delivery systems.