Exploring the Potential of Mesoporous Silica as a Carrier for Puerarin: Characterization, Physical Stability, and In Vivo Pharmacokinetics.

The aim of this study was to evaluate the use of a novel porous silica carrier, AEROPERL® 300 Pharma (AP), to improve the in vitro release and oral bioavailability of puerarin (PUE) in solid dispersions (SDs). PUE-AP SD formulations with different ratios of drug to silica (RDS) were prepared by the solvent method. The scanning electron microscopy (SEM) results indicated that the dispersion of PUE improved as the concentration of AP was increased. The differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results revealed that PUE mostly existed in an amorphous state in the SDs. The rate of drug dissolution from the SDs was significantly higher than that from the PUE powder (p < 0.05). The in vitro drug release percentage from the PUE-AP SDs increased as the RDS was reduced. The oral bioavailability of PUE from the SDs improved when using AP, as indicated by AUC(0-∞), which was 2.05 and 2.01 times greater than that of the PUE (API) and PVP K30 SDs, respectively (p < 0.05). The drug content, in vitro release profiles, and the amorphous state of PUE in the PUE-AP SDs showed no significant changes after being stored at room temperature for 6 months or under accelerated conditions (40 ± 2°C, 75 ± 5% relative humidity) for 3 months. AP has a high pore volume, large specific surface area, excellent flowability, and hydrophilic properties, making it capable of improving the dissolution and bioavailability of poorly water-soluble drugs.

Microplastics in urban soils of Nanjing in eastern China: Occurrence, relationships, and sources.

Although microplastic (MP) pollution has been defined as a new global challenge by the United Nations Environment Programme, their abundance and composition has only been studied in-depth within farmland soil, while minimal attention has been placed on urban soil contamination. Accordingly, within the current study, MP abundance and composition is investigated within urban soil from green spaces in Nanjing, eastern China. The average MP abundance in soil was 461 ± 222 items/kg and primarily comprised fibers (39.1%) and fragments (37.7%). MPs <1000 µm in size accounted for 83.7% of the total content and white MPs were the most abundant (26.5%). The dominant polymers were polyethylene glycol terephthalate (32.0%) and polypropylene (20.5%). Moreover, relationship network analysis generated three distinct MP modules based on community similarity. Indeed, the degree of similarity increased by ∼26.8% per kilometer. Furthermore, application of a forward selective optimal multiple regression model identified clay, sand, longitude, and points of interest for recycling bins (RecyclePOI) as the primary spatial and soil environmental factors affecting MP abundance and composition. Additionally, five potential sources of MPs were identified based on the MP diversity integrated index fitting results, and point of interest density (MDII-POI) source analysis (R2 = 0.21-0.62; P < 0.05). In particular, the point of interest of express delivery points (ExpressPOI) were important sources of plastic emissions as they are widely distributed throughout urban and fringe areas. Collectively, the findings of this study provide novel insights regarding quantitative source appointment and regional ecological control of MPs in urban soil.

Degradation of polyvinyl alcohol (PVA) by UV/chlorine oxidation: Radical roles, influencing factors, and degradation pathway.

Polyvinyl alcohol (PVA) is widely used in industry but is difficult to degrade. In this study, the synergistic effect of UV irradiation and chlorination on degradation of PVA was investigated. UV irradiation or chlorination alone did not degrade PVA. By contrast, UV/chlorine oxidation showed good efficiency for PVA degradation via generation of active free radicals, such as OH and Cl. The relative importance of these two free radicals in the oxidation process was evaluated, and it was shown that OH contributed more to PVA degradation than Cl did. The degradation of PVA followed pseudo first order kinetics. The rate constant k increased linearly from 0 min-1 to 0.3 min-1 with increasing chlorine dosage in range of 0 mg/L to 20 mg/L. However, when the chlorine dosage was increased above 20 mg/L, scavenging effect of free radicals occurred, and the degradation efficiency of PVA did not increase much more. Acidic media increased the degradation efficiency of PVA by UV/chlorine oxidation more than basic or neutral media because of the higher ratio of [HOCl]/[OCl-], higher free radical quantum yields, and the lower free radical quenching effect under acidic conditions. Results of Fourier Transform Infrared Spectroscopy showed that carbonyl groups in degradation products were formed during UV/chlorine oxidation, and a possible degradation pathway via alcohol to carbonyl was proposed.

Long-term ultrasound biomicroscopy observation of position changes of a copolymer posterior chamber phakic intraocular lens.

PURPOSE: To evaluate longitudinal changes in Implantable Collamer Lens phakic intraocular lens (pIOL) position after implantation. SETTING: Department of Ophthalmology, Zhejiang University, Hangzhou, China. DESIGN: Retrospective case series. METHODS: Myopic eyes that had pIOL implantation with a follow-up of at least 24 months were evaluated. Ultrasound biomicroscopy examinations were performed at each visit. RESULTS: The study enrolled 62 eyes (31 patients; 22 women, 9 men) ranging in age from 21 to 46 years. The manifest spherical equivalent ranged from -8.25 to -18.75 diopters. A significant increase (mean 36 µm±50 [SD]) in the endothelium-anterior pIOL distance occurred between 1 month and 3 months (P=.000); afterward, the distance decreased slowly (P>.05). The largest decrease (mean 47±17 µm) in central vault occurred between 1 month and 3 months (P=.009). The largest decrease (mean 21±14 µm) in peripheral vault occurred between 1 month and 3 months (P=.000). CONCLUSIONS: A significant increase in the endothelium-anterior pIOL distance occurred from 1 month to 3 months postoperatively, after which a slight decrease occurred over time. Central vault and peripheral vault had a tendency to decrease over time. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.