A ternary system of meloxicam with matching hydrophilic polymer and cyclodextrin for improved stability in liquid preprations.

The purpose of the study is to investigate the effect of ternary systems consisting of meloxicam with cyclodextrins (HP-ß-CD or SBE-ß-CD) and different polymers (HA, HPMC and PVP) on the stability of meloxicam. The t 0.9 values of meloxicam were determined within all the aforementioned systems and the influence of various polymers on the alteration in meloxicam's stability was evaluated. All three polymers altered the stability of meloxicam to varying degrees, with the extent of the effect being related to hydrophilicity, concentration of components, and the interaction of the newly formed ternary system. Among them, meloxicam demonstrated its highest degree of stabilization within the ternary system formed by SBE-ß-CD&HPMC and HP-ß-CD&HA. We characterized the ternary system of meloxicam using differential scanning calorimetry (DSC), X-ray diffraction, and scanning electron microscopy analysis, which determined the presence of ternary system inclusions. In addition, we investigated the optimized prescription of eye drops of meloxicam using the ternary system and further determined that the ternary system improved the stability of the drug in liquid formulations.

Durability and Degradation Mechanisms of Antifrosting Surfaces.

Rapid implementation of renewable energy technologies has exacerbated the potential for economic loss and safety concerns caused by ice and frost accretion, which occurs on the surfaces of wind turbine blades, photovoltaic panels, and residential and electric vehicle air-source heat pumps. The past decade has seen advances in surface chemistry and micro- and nanostructures that can promote passive antifrosting and enhance defrosting. However, the durability of these surfaces remains the major obstacle preventing real-life applications, with degradation mechanisms remaining poorly understood. Here, we conducted durability tests on antifrosting surfaces, including superhydrophobic, hydrophobic, superhydrophilic, and slippery liquid-infused surfaces. For superhydrophobic surfaces, we demonstrate durability with progressive degradation for up to 1000 cycles of atmospheric frosting-defrosting and month-long outdoor exposure tests. We show that progressive degradation, as reflected by increased condensate retention and reduced droplet shedding, results from molecular-level degradation of the low-surface-energy self-assembled monolayer (SAM). The degradation of the SAM leads to local high-surface-energy defects, which further deteriorate the surface by promoting accumulation of atmospheric particulate matter during cyclic condensation, frosting, and melt drying. Furthermore, cyclic frosting and defrost tests demonstrate the durability and degradation mechanisms of other surfaces to show, for example, the loss of water affinity of superhydrophilic surfaces after 22 days due to atmospheric volatile organic compound (VOC) adsorption and significant lubricant drainage for lubricant-infused surfaces after 100 cycles. Our work reveals the degradation mechanism of functional surfaces during exposure to long-term frost-defrost cycling and elucidates guidelines for the development of future surfaces for real-life antifrosting/icing applications.

Insect-scale jumping robots enabled by a dynamic buckling cascade.

Millions of years of evolution have allowed animals to develop unusual locomotion capabilities. A striking example is the legless-jumping of click beetles and trap-jaw ants, which jump more than 10 times their body length. Their delicate musculoskeletal system amplifies their muscles' power. It is challenging to engineer insect-scale jumpers that use onboard actuators for both elastic energy storage and power amplification. Typical jumpers require a combination of at least two actuator mechanisms for elastic energy storage and jump triggering, leading to complex designs having many parts. Here, we report the new concept of dynamic buckling cascading, in which a single unidirectional actuation stroke drives an elastic beam through a sequence of energy-storing buckling modes automatically followed by spontaneous impulsive snapping at a critical triggering threshold. Integrating this cascade in a robot enables jumping with unidirectional muscles and power amplification (JUMPA). These JUMPA systems use a single lightweight mechanism for energy storage and release with a mass of 1.6 g and 2 cm length and jump up to 0.9 m, 40 times their body length. They jump repeatedly by reengaging the latch and using coiled artificial muscles to restore elastic energy. The robots reach their performance limits guided by theoretical analysis of snap-through and momentum exchange during ground collision. These jumpers reach the energy densities typical of the best macroscale jumping robots, while also matching the rapid escape times of jumping insects, thus demonstrating the path toward future applications including proximity sensing, inspection, and search and rescue.

Laplace Pressure Driven Single-Droplet Jumping on Structured Surfaces.

Droplet transport on, and shedding from, surfaces is ubiquitous in nature and is a key phenomenon governing applications including biofluidics, self-cleaning, anti-icing, water harvesting, and electronics thermal management. Conventional methods to achieve spontaneous droplet shedding enabled by surface-droplet interactions suffer from low droplet transport velocities and energy conversion efficiencies. Here, by spatially confining the growing droplet and enabling relaxation via rationally designed grooves, we achieve single-droplet jumping of micrometer and millimeter droplets with dimensionless jumping velocities v* approaching 0.95, significantly higher than conventional passive approaches such as coalescence-induced droplet jumping (v* ≈ 0.2-0.3). The mechanisms governing single-droplet jumping are elucidated through the study of groove geometry and local pinning, providing guidelines for optimized surface design. We show that rational design of grooves enables flexible control of droplet-jumping velocity, direction, and size via tailoring of local pinning and Laplace pressure differences. We successfully exploit this previously unobserved mechanism as a means for rapid removal of droplets during steam condensation. Our study demonstrates a passive method for fast, efficient, directional, and surface-pinning-tolerant transport and shedding of droplets having micrometer to millimeter length scales.

[Pharmaceutical evaluation of hydroxycamptothecin nanosuspensions with the action of inhibiting P-gp].

Oral hydroxycamptothecin nanosuspension (HCPT-Nano) with high supersaturated dissolution level, high permeation and well physical stability, was manufactured by microprecipitation-high press homogenization method. Its pharmaceutical properties were investigated, such as size and distribution, zeta potential, particle shape, physical existence condition, supersaturated dissolution level and so on. Particle size was measured by laser diffraction, and the mean diameters before and after lyophilization were 138 +/- 11.72 nm and 175 +/- 12.74 nm, respectively, for HCPT-Nano. Zeta potentials of HCPT-Nano was over -20 mV. The nanoparticles, being observed by transmission electron microscopy (TEM), were claviform or column in shape. DSC and X-ray diffraction revealed that HCPT existed in the form of crystal for HCPT-Nano. And HCPT-Nano could maintain higher supersaturated dissolution level for long time. So it supplied the possibility of improving oral bioavailability of HCPT when combining together admoveatur of P-gp inhibitor, CsA.

Development of novel self-assembled DS-PLGA hybrid nanoparticles for improving oral bioavailability of vincristine sulfate by P-gp inhibition.

To improve the encapsulation efficiency and oral bioavailability of vincristine sulfate (VCR), novel self-assembled dextran sulphate-PLGA hybrid nanoparticles (DPNs) were successfully developed using self-assembly and nanoprecipitation method. By introducing the negative polymer of dextran sulphate sodium (DS), VCR was highly encapsulated (encapsulation efficiency up to 93.6%) into DPNs by forming electrostatic complex. In vitro release of VCR solution (VCR-Sol) and VCR-loaded DPNs (VCR-DPNs) in pH 7.4 PBS showed that about 80.4% of VCR released from VCR-DPNs after 96h and burst release was effectively reduced, indicating pronounced sustained-release characteristics. In vivo pharmacokinetics in rats after oral administration of VCR-Sol and VCR-DPNs indicated that the apparent bioavailability of VCR-DPNs was increased to approximate 3.3-fold compared to that of VCR-Sol. The cellular uptake experiments were conducted by quantitative assay of VCR cellular accumulation and fluorescence microscopy imaging of fluorescent labeled DPNs in two human breast cancer cells including MCF-7 and P-glycoprotein over-expressing MCF-7/Adr cells. The relative cellular uptake of VCR-DPNs was 12.4-fold higher than that of VCR-Sol in MCF-7/Adr cells implying that P-glycoprotein-mediated drug efflux was diminished by the introduction of DPNs. The new DPNs might provide an effective strategy for oral delivery of VCR with improved encapsulation efficiency and oral bioavailability.