Nanoemulsion-based dissolving microneedle arrays for enhanced intradermal and transdermal delivery

The development of dissolving microneedles (DMN) is one of the advanced technologies in transdermal drug delivery systems, which precisely deliver the drugs through a rapid dissolution of polymers after insertion into the skin. In this study, we fabricated nanoemulsion-loaded dissolving microneedle (DMN) arrays for intradermal and transdermal drug delivery. For this task, model drug (amphotericin B, AmB)-loaded nanoemulsion (NE) were prepared by the probe-sonication method. AmB-loaded-NE was prepared using Capmul MCM C-8 EP/NF, Tween® 80, poly(vinyl alcohol) (PVA-10 kDa), and poly (vinyl pyrrolidone) (PVP-360 kDa or K29/32) by using SpeedMixer™, followed by probe-sonication and evaluated for particle size and polydispersity index (PDI). Transmission electron microscopy (TEM) was also used to assess the particle size before and after DMN casting. AmB-NE embedded DMN arrays were found to be strong enough, revealed efficient skin insertion, and penetrated down to the fourth layer (depth ≈ 508 μm) of Parafilm M® (validated skin model). Ex vivo skin deposition experiments in full-thickness neonatal porcine demonstrated that after 24 h, AmB-NE-DMN arrays were able to deposit 111.05 ± 48.4 µg/patch AmB into the skin. At the same time, transdermal porcine skin permeation studies showed significantly higher permeability of AmB (29.60 ± 8.23 μg/patch) from AmB-NE-DMN compared to MN-free AmB-NE patches (5.0 ± 6.15 μg/patch) over 24 h. Antifungal studies of optimized AmB-NE-DMN, AmB-loaded discs and drug-free DMN against Candida albicans, confirmed the synergistic activity of Campul-MCM C-8, used in the nanoemulsion formulation. This study establishes that nanoemulsion based dissolving microneedle may serve as an efficient system for intradermal as well as transdermal drug delivery. Graphical abstract

Ophthalmic Delivery of Riboflavin Loaded Nanoparticulate Suspension in Keratoconus: A Preclinical Study in Rabbit Model

The present investigation undertakes the formulation of nanoparticulate suspension of Riboflavin to treat keratoconus disease by applying it to the infected mice corneas. The nanoparticles of Riboflavin were prepared using single solvent evaporation method and later formulated as suspension using continuous probe sonication method. Then, both riboflavin nanoparticles and suspension were evaluated for various parameters. The nanoparticles showed smooth and spherical surface with in vitro drug release up to 77.89%. The drug content was found to be 97.23%–98.89%. The suspension was found to be visually clear with pH ranging from 6 to 7. The drug entrapment was found to be from 76.37% to 97.34%. Since there was no hemolytic activity, this formulation was suitable for ophthalmic administration. The Draize test confirmed the non-irritant, non-itchy nature of formulation. The prepared formulations, such as nanoparticulate gel and suspension, were found to be significantly efficacious in experimental animals.

Comparative Assessment of Physical and Chemical Cyanobacteria Cell Lysis Methods for Total Microcystin-LR Analysis

Standardization and validation of alternative cell lysis methods used for quantifying total cyanotoxins is needed to improve laboratory response time goals for total cyanotoxin analysis. In this study, five cell lysis methods (i.e., probe sonication, microwave, freeze-thaw, chemical lysis with Abraxis QuikLyseTM, and chemical lysis with copper sulfate) were assessed using laboratory-cultured Microcystis aeruginosa (M. aeruginosa) cells. Methods were evaluated for destruction of cells (as determined by optical density of the sample) and recovery of total microcystin-LR (MC-LR) using three M. aeruginosa cell densities (i.e., 1 × 105 cells/mL (low-density), 1 × 106 cells/mL (medium-density), and 1 × 107 cells/mL (high-density)). Of the physical lysis methods, both freeze-thaw (1 to 5 cycles) and pulsed probe sonication (2 to 10 min) resulted in >80% destruction of cells and consistent (>80%) release and recovery of intracellular MC-LR. Microwave (3 to 5 min) did not demonstrate the same decrease in optical density (<50%), although it provided effective release and recovery of >80% intracellular MC-LR. Abraxis QuikLyseTM was similarly effective for intracellular MC-LR recovery across the different M. aeruginosa cell densities. Copper sulfate (up to 500 mg/L Cu2+) did not lyse cells nor release intracellular MC-LR within 20 min. None of the methods appeared to cause degradation of MC-LR. Probe sonication, microwave, and Abraxis QuikLyseTM served as rapid lysis methods (within minutes) with varying associated costs, while freeze-thaw provided a viable, low-cost alternative if time permits.

Electrochemical sensing of dextrose and Photocatalytic activities by nickel ferrite nanoparticles synthesized by probe sonication method

Background: Electrochemical sensing has been widely used as a glucose sensor. Methods: In the present work, we have investigated the application of nickel ferrite (NiFe2O4) nanoparticles (NFNPs) for dextrose sensing applications. NFNPS were synthesized by using a simple and low-cost probe sonication method (PSM). The structural, optical and electrochemical properties of prepared nanoparticles were measured by using XRD, FTIR and DRS techniques. Results: The PXRD pattern confirmed the formation of inverse spinel structure for NFNPs with a face-cente red cubic (FCC) structure. The diffuse reflectance spectral studies revealed the energy band gap of NFNPs as deduced to be 2.50 eV by using Kubelka-Munk function. The efficiencies in the photocatalytic degradation of Acid Red 88 (AR-88) and Acid Blue 88 (AB-88) dyes were found to be better with 93.45% and 84.45%, respectively. The EIS parameters corroborated the significant reduction in the charge transfer resistance of NFNPs electrode. The sensing of dextrose in acidic solution by using NFNP through carbon paste electrode was successful. Conclusion: The obtained sensing and photocatalytic results revealed that the synthesized NFNPs could be a better electrode material for the detection of dextrose with high electrode reversibility, in addition to its excellent photocatalytic characteristics towards the dye degradation.

Development of Apigenin-Loaded Niosomes Using Ecological Probe Sonication Technique for enhanced oral delivery: Application of Box-Behnken Design

Background: Apigenin (APG), a natural bioactive flavonoid, has multiple pharmacological effects. However, its poor aqueous solubility hinders its clinical benefits. Objective and Methods: The work aimed to develop novel apigenin-loaded niosomes (APG-NIO) with ecological probe sonication techniques. The formulation was statistically optimized by Box-Behnken design (BBD), and the independent variables were selected as Span 80 (X1), Poloxamer 188 (X2), and Tween 80 (X3) at three levels, and the dependent variables were identified as: particle size (Y1), polydispersity index (Y2), and % entrapment efficiency (Y3). The formulation was characterized for various parameters such as vesicle shape, size, PDI, %EE, solubility, in vitro drug release, and antioxidant potential. Results: The optimized APG-NIO formulation was found to have a spherical shape with homogenous distribution and a low polydispersity index. It has a particle size of 425.77 nm, zeta potential -17.1±0.9 mV, and %EE of 89.63. The aqueous solubility of APG-NIO was found approximately 45 times higher than that of pure APG. The formulation showed a higher drug release rate as compared to pure APG in phosphate buffer pH 7.4 and followed the Higuchi release model with a non-Fickian transport mechanism. The stability was found at 4°C for 3 months. The antioxidant potential of APG-NIO was significantly increased in comparison to the pure drug suspension in the DPPH• assay. Conclusion: These findings suggest that the probe sonication technique is an alternative, cost-effective, simple, and green method for the development of niosomes, and BBD is a useful optimization tool for identifying the effect of formulation variables.

Effect of Ultraviolet Irradiation on Photo-Physical and Surface Electronic Properties of MoS2

In this study, exfoliation of molybdenum disulfide (MoS2) using the chemical exfoliation method was successfully achieved via probe sonication followed by centrifugation. The observed ultravioletvisible (UV-Vis) spectra of the MoS2 dispersions indicated the presence of a few layers of MoS2. The morphological, structural, optical and surface electronic properties before and after UV light irradiation were investigated by the technique of X-ray diffraction, the Raman spectroscopic measurements, transmission electron microscopy (TEM), and the scanning Kelvin probe microscopy (SKPM). It was observed that after UV irradiation, the Fermi level moves towards the valence band.

STRUCTURAL AND MORPHOLOGICAL INVESTIGATION OF FUNCTIONALIZED REDUCED GRAPHENE OXIDE-MULTI WALLED CARBON NANOTUBES NANOCOMPOSITE

2D materials like Graphene and its composite has emerged as most valuable and major concern because of their peculiar properties in field of nanotechnology in past few decades. Herein, we report the effective technique for the synthesis of functionalized r-GO/MWCNTs nanocomposite using probe sonication. The synthesized samples were tested via XRD, FESEM, FTIR and Raman Spectroscopy. X-ray diffraction technique was used for the structural analysis of the samples which revealed that most prominent peak was observed around 2θ~26°. Surface morphology of the samples were studied via FESEM, which revealed that r-GO layers were wrapped around the MWCNTs. Raman spectra were recorded for the determination of quality of r-Go and MWCNT via the position and intensity of D and G band. The various functionalities present on the samples were identified via FTIR spectra.