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1.
Pharmaceuticals (Basel) ; 17(3)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38543057

RESUMO

BACKGROUND: Drug release from controlled release delivery systems is influenced by various factors, including the polymer's grade and the drug's hydration form. This study aimed to investigate the impact of these factors on the controlled release of theophylline (THN). This research compares the monohydrate form found in branded products with the anhydrous form in generic equivalents, each formulated with different polymer grades. METHODS: Quality control assessment was conducted alongside in vitro evaluation, complemented by various analytical techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). Additionally, thermal analyses using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were employed. RESULTS: Quality control assessments demonstrated that the generic tablets exhibited lower average weight and resistance force compared to the branded ones. In vitro tests revealed that generic tablets released contents within 120 min, compared to 720 min for the branded counterpart. Characterization using XRD and SEM identified disparities in crystallinity and particle distribution between the three samples. Additionally, the thermal analysis indicated consistent endothermic peaks across all samples, albeit with minor variations in heat flow and decomposition temperatures between the two products. CONCLUSIONS: This study demonstrated that variations in polymer grade and hydration form significantly impact THN release.

2.
Environ Pollut ; 346: 123645, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38402939

RESUMO

Brominated flame retardants (BFRs) are bromine-bearing additives added to the polymeric fraction in various applications to impede fire ignition. The Stockholm Convention and various other legislations abolished legacy BFRs usage and hence, the so-called novel BFRs (NBFRs) were introduced into the market. Recent studies spotlighted their existence in household dust, aquifers and aquatic/aerial species. Co-pyrolysis of BFRs with metal oxides has emerged as a potent chemical recycling approach that produces a bromine-free stream of hydrocarbon. Herein, we investigate the debromination of two prominent two NBFRs; namely tetrabromobisphenol A 2,3-dibromopropyl ether (TD) and tetrabromobisphenol A diallyl ether (TAE) through their co-pyrolysis with zinc oxide (ZnO) and franklinite (ZnFe2O4). Most of the zinc content in electrical arc furnace dust (EAFD) exists in the form of these two metal oxides. Conversion of these metal oxides into their respective bromides could also assist in the selective extraction of the valuable zinc content in EAFD. The debromination potential of both oxides was unveiled via a multitude of characterization studies to analyze products (char, gas and condensates). The thermogravimetric analysis suggested a pyrolytic run up to 500 °C and the TAE treatment with ZnO produced only a trivial amount of brominated compounds (relative area, 0.83%). Phenol was the sole common compound in condensable products; potentially formed by the ß-scission debromination reaction from the parental molecular skeleton. Inorganic compounds and methane were the major constituents in the gaseous products. The pyrochar analyses confirmed the presence of metal bromides retained in the residue, averting the bromine release into the atmosphere. The ion chromatography analysis portrayed <8% of HBr gas release into the atmosphere upon pyrolysis with ZnO. The ZnO dominance herein envisaged further probes into other spinel ferrites in combating brominated polymers.


Assuntos
Resíduo Eletrônico , Retardadores de Chama , Hidrocarbonetos Bromados , Bifenil Polibromatos , Óxido de Zinco , Retardadores de Chama/análise , Resíduo Eletrônico/análise , Bromo , Brometos , Reciclagem/métodos , Polímeros , Zinco/análise , Poeira , Éteres , Hidrocarbonetos Bromados/análise
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