BACKGROUND: A sustained release system for losartan potassium designed to delay its residence time in the stomach through the preparation of solvent evaporation technique-based floating microspheres. The influence of the different grades of Ethocel™ such as 4 cps, 10 cps, and 22 cps as well as the drug: polymer ratio on various properties of microspheres were tested.
METHODS: Thermal and functional analysis revealed no interaction between the encapsulated drug and polymer. The results indicated that the mean diameter of microspheres increased with a change in grades of ethyl cellulose relating to viscosity. However, the drug incorporation efficiency within ethyl cellulose microspheres decreased with increasing viscosity of ethyl cellulose.
RESULTS: The bulk density of the formulations was proportionally dependent on concentration and the viscosity of the polymer, which resulted in a decrease in floating capacity from 90.02% to 73.58%. Moreover, the drug release was indirectly proportional to the viscosity of ethyl cellulose tested. The in vitro release profile exhibited a burst effect with a biphasic release pattern following Fickian diffusion, indicating a diffusioncontrolled release mechanism.
CONCLUSIONS: The results demonstrated that the viscosity of ethyl cellulose significantly affects the floating capacity and drug release pattern from microspheres.

The aim in this study was to develop and evaluate a nanofluconazole (FLZ) formulation with increased solubility and permeation rate using nanosuspensions. The FLZ nanosuspensions were stabilized using a variety of stabilizing agents and surfactants in various concentrations. The FLZ nanosuspension was characterized in vitro using particle size, zeta potential, X-ray powder diffraction (XRPD), and solubility. In addition, the ex vivo ocular permeation of FLZ through a goat cornea was analyzed. The results showed that the particle size of all nanosuspension formulations was in the nanometer range from 174.5 ± 1.9 to 720.2 ± 4.77 nm; that of the untreated drug was 18.34 μm. The zeta potential values were acceptable, which indicated suitable stability for formulations. The solubility of the nanosuspensions was up to 5.7-fold higher compared with that of the untreated drug. The results of the ex vivo ocular diffusion of the FLZ nanosuspensions showed the percentage of FLZ penetrating via the goat cornea increased after using Kollicoat to stabilize the nanosuspension formulation. Consequently, when using a nanosuspension formulation of Kollicoat, the antifungal activity of the drug strengthens.

Solvent evaporation within an adhesive layer is a crucial step during a bonding process. The aim of this current research was to test whether the use of different air temperatures (20 °C, 40 °C, and 60 °C) for solvent evaporation improves the performance of four adhesive systems to dentin. Sixty non-carious human molar teeth were randomly prepared for micro-tensile bond strength (μTBS) tests. Four different adhesive systems, Prime&Bond Universal (PBU), OptiBond Universal (OBU), OptiBond FL (OBFL), and Clearfil SE (CSE), were applied following the manufacturer\'s instructions. Three groups based on the air-drying temperature were used: solvent evaporation was performed with either of warm (40 °C), (60 °C), and cold air as control group (20 °C) for 10 s at a distance of 5 cm. In all bonded surfaces, three resin composite (Reflectys, Itena Clinical, Paris, France) layers of 2 mm thickness were built up. The resin-dentin samples were kept in distilled water at 37 °C for 24 h and 6 months, respectively, before μTBS testing. Failure analysis, scanning electron microscopy of resin-dentin bonded interface, and solvent evaporation rate were tested as secondary variables. All analyses were conducted using a significance level of α = 0.05. Bond strength (BS) values were similar among all the adhesive systems used (p > 0.05). Also, the aging factor did not affect the BS (p > 0.05). Only the factor of temperature used for solvent evaporation resulted in a statistically significant effect (p < 0.05), with the temperature of 60 °C being the highest value (p < 0.05). A failure mode evaluation revealed mostly adhesive or mixed modes of failures in all the different temperatures of air used for the solvent evaporation of each adhesive system. The thickness of the adhesive layer and the creation of resin tags varied amongst the temperatures evaluated. For all adhesive systems tested, the use of 40 °C or 60 °C air for solvent evaporation led to an increased mass loss. Warmer temperatures for solvent evaporation contributed positively to bonding performance, enhancing both the quality of the adhesive layer and its interaction with the dentin tissue. Optimizing solvent evaporation with warmer air temperatures (40 °C and 60 °C) significantly improved µTBS, offering a practical means to enhance the quality and longevity of adhesive restorations in esthetic dentistry.

We introduce a Molecular Theory for Compressible Fluids (MOLT-CF) that enables us to compute free energies and other thermodynamic functions for nanoparticle superlattices with any solvent content, including the dry limit. Quantitative agreement is observed between MOLT-CF and united-atom molecular dynamics simulations performed to assess the reliability and precision of the theory. Among other predictions, MOLT-CF shows that the amount of solvent within the superlattice decreases approximately linearly with its vapor pressure and that in the late stages of drying, solvent-filled voids form at lattice interstitials. Applied to single-component superlattices, MOLT-CF predicts fcc-to-bcc Bain transitions for decreasing vapor pressure and for increasing ligand length, both in agreement with experimental results. We explore the stability of other single-component phases and show that the C14 Frank-Kasper phase, which has been reported in experiments, is not a global free-energy minimum. Implications for precise assembly and prediction of multicomponent nanoparticle systems are discussed.

OBJECTIVE: To prepare aloe-emodin solid dispersion (AE-SD) and determine the metabolic process of AE and AE-SD in vivo.
METHODS: AE-SD was prepared viasolvent evaporation or solvent melting using PEG-6000 and PVP-K30 as carriers. Thermogravimetric analysis, X-ray diffraction spectroscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy and scanning electron microscopy were used to identify the physical state of AE-SD. Optimal prescriptions were screened viathe dissolution degree determination method. Using Phoenix software, AE suspension and AE-SD were subjected to a pharmacokinetic comparison study analyzing the alteration of behavior in vivo after AE was prepared as a solid dispersion. Acute toxicity was assessed in mice, and the physiological toxicity was used as the determination criterion for toxicity.
RESULTS: AE-SD showed that AE existed in the carrier in an amorphous state. Compared with polyethylene glycol, polyvinylpyrrolidone (PVP) inhibited AE crystallization, causing the drug to transform from a dense crystalline state to an amorphous form and increasing the degree of drug dispersion. Therefore, it was more suitable as a carrier material for AE-SD. The addition of poloxamer (POL) was more beneficial to the stability of solid dispersions and could reduce the amount of PVP. The dissolution test confirmed that the optimal ratio of AE to the composite vector AE-PVP-POL was 1：2：2, and its dissolution effect was also optimal. Based on the pharmacokinetic comparison, the drug absorption was faster and quickly reached the peak of blood drug concentration in AE-SD compared to AE, the Cmax of AE-SD was greater than that of AE, and t1/2 and mean residence time of AE-SD were less than AE. The results showed that the drug metabolism in AE-SD was better, and the residence time was shorter. The toxicology study showed that both AE and AE-SD had no toxicity.
CONCLUSIONS: This paper established that the solubility of the drug could be increased after preparing a solid dispersion, as demonstrated by in vitro dissolution experiments. In vivo pharmacokinetics studies confirmed that AE-SD could improve the bioavailability of AE in vivo, providing a new concept for the research and development of AE preparations.

Euglena gracilis (EG) is a unicellular freshwater alga known for its high β-1,3-glucan (BG) content with well-known biological properties and immune response. The high molecular weight structure of BG traditionally poses a challenge in terms of its size and absorption. Therefore, the aim of this study was to develop a novel drug delivery mechanism of BG and EG to nanophytosomes (NPs) by converting the heavy molecular weight of BG and EG into lipid phosphatidylcholine (PC), which plays an important role in improving their bioavailability and entrapment in captivity. The BG and EG NPs were developed by the solvent evaporation method while varying time and temperature to optimize their drug delivery ability. The size of BG-PC and EG-PC obtained by the Dynamic Light Scattering (DLS) method was 134.62 and 158.38 nm, respectively. Chemical (Fourier Transform Infra-Red) and structural (X-Ray Diffraction) characterization of NPs improved the binding capacity and the amorphous nature of both NPs. The shape of the NPs by Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) revealed their spherical, vesicular nature. The encapsulation efficiency of BG-PC and EG-PC was 82 ± 1.62 % and 87 ± 3.22 %, respectively, which improves the bioavailability. The developed methodology has thus proven effective in synthesizing BG-PC and EG-PC, which may be useful as NP drug delivery carriers. Future research could demonstrate the safety and effectiveness of long-term storage conditions for medical and pharmaceutical applications.•Nanophytosomes are tailored in size, shape and composition to optimize the delivery of phytochemicals/phytocompounds through nanoscale size and surface modification for better physiological absorption.•Nanophytosomes increase the stability of phytochemicals/phytocompounds and protect them from degradation due to heat or chemical reactions, leading to longer shelf life and improved therapeutic efficacy.•In this method, optimal conditions were created for the formation of β-1,3-glucan and Euglena gracilis extract nanophytosomes for successful development of drug delivery system that can effectively deliver bioactive compounds.

The once-weekly Bydureon® (Bdn) PLGA microsphere formulation encapsulating the GLP-1 receptor agonist, exenatide acetate, is an important complex injectable product prepared by coacervation for the treatment of type 2 diabetic patients. Encapsulation by coacervation is useful to minimize an undesirable initial burst of exenatide, but it suffers from manufacturing difficulties such as process scale-up and batch-to-batch variations. Herein we prepared exenatide acetate-PLGA formulations of similar compositions using the desirable alternative double emulsion-solvent evaporation technique. After screening several process variables, we varied the PLGA concentration, the hardening temperature, and the collected particle size range, and determined the resulting drug and sucrose loading, initial burst release, in vitro retention kinetics, and peptide degradation profiles using Bdn as a positive control. All formulations exhibited a triphasic release profile with a burst, lag, and rapid release phase, although the burst release was greatly decreased to <5% for some. Marked differences were observed in the peptide degradation profiles, particularly the oxidized and acylated fractions, when the polymer concentration was varied. For one optimal formulation, the release and peptide degradation profiles were similar to Bdn microspheres, albeit with an induction time shift of one week, likely due to the slightly higher Mw of PLGA in Bdn. These results highlight the effects of key manufacturing variables on drug release and stability in composition-equivalent microspheres encapsulating exenatide acetate and indicate the potential of manufacturing the microsphere component of Bdn by solvent evaporation.

Hypothesis Nonaqueous foams are found in a variety of applications, many of which contain volatile components that need to be removed during processing. Sparging air bubbles into the liquid can be used to aid in their removal, but the resulting foam can be stabilized or destabilized by several different mechanisms, the relative importance of which are not yet fully understood. Investigating the dynamics of thin film drainage, four competing mechanisms can be observed, such as solvent evaporation, film viscosification, and thermal and solutocapillary Marangoni flows. Experiments Experimental studies with isolated bubbles and/or bulk foams are needed to strengthen the fundamental knowledge of these systems. This paper presents interferometric measurements of the dynamic evolution of a film formed by a bubble rising to an air-liquid interface to shed light on this situation. Two different solvents with different degrees of volatility were investigated to reveal both qualitative and quantitative details on thin film drainage mechanisms in polymer-volatile mixtures. Findings Using interferometry, we found evidence that solvent evaporation and film viscosification both strongly influence the stability of interface. These findings were corroborated by comparison with bulk foam measurements, revealing a strong correlation between these two systems.

In this study, high energy ball milling and nano spray drying were used to prepare amorphous solid dispersions of bosentan in copovidone for the first time. In particular, the impact of this polymer on the bosentan amorphization kinetics was investigated. Copovidone was shown to facilitate the amorphization of bosentan upon ball milling. As a result, bosentan was dispersed in copovidone at the molecular level, forming amorphous solid dispersions, regardless of the ratio of the compounds. The similarity between the values of the adjustment parameter that describes the goodness of fit of the Gordon-Taylor equation to the experimental data (K = 1.16) and that theoretically calculated for an ideal mixture (K = 1.13) supported these findings. The kind of coprocessing method determined the powder microstructure and the release rate. The opportunity to prepare submicrometer-sized spherical particles using nano spray drying was an important advantage of this technology. Both coprocessing methods allowed the formation of long-lasting supersaturated bosentan solutions in the gastric environment with maximum concentrations reached ranging from four (11.20 μg/mL) to more than ten times higher (31.17 μg/mL) than those recorded when the drug was vitrified alone (2.76 μg/mL). Moreover, this supersaturation lasted for a period of time at least twice as long as that of the amorphous bosentan processed without copovidone (15 min vs. 30-60 min). Finally, these binary amorphous solid dispersions were XRD-amorphous for a year of storage under ambient conditions.

In this work, we subjected hybrid lead-mixed halide perovskite (CH3NH3PbI3-xClx) precursor inks to different solvent evaporation rates in order to facilitate the nucleation and growth of perovskite crystals. By controlling the temperature of perovskite solutions placed within open-air rings in precise volumes, we established control over the rate of solvent evaporation and, thus, over both the growth rate and the shape of perovskite crystals. Direct utilization of diluted lead-mixed halide perovskites solutions allowed us to control the nucleation and to favor the growth of only a low number of perovskite crystals. Such crystals exhibited a clear sixfold symmetry. While crystals formed at a lower range of temperatures (40-60 °C) exhibited a more compact dendritic shape, the crystals grown at a higher temperature range (80-110 °C) displayed a fractal dendritic morphology.