Approximately 1 billion people are affected by neglected diseases around the world. Among these diseases, schistosomiasis constitutes one of the most important public health problems, being caused by Schistosoma mansoni and treated through the oral administration of praziquantel (PZQ). Despite being a common disease in children, the medication is delivered in the form of large, bitter-tasting tablets, which makes it difficult for patients to comply with the treatment. In order to mask the taste of the drug, allow more appropriate doses for children, and enhance the absorption by the body, different polymer matrices based on poly(methyl methacrylate) (PMMA) were developed and used to encapsulate PZQ. Polymer matrices included PMMA nano- and microparticles, PMMA-co-DEAEMA (2-(diethylamino)ethyl methacrylate), and PMMA-co-DMAEMA (2-(dimethylamino)ethyl methacrylate) microparticles. The performances of the drug-loaded particles were characterized in vitro through dissolution tests and in vivo through pharmacokinetic analyses in rats for the first time. The in vitro dissolution studies were carried out in accordance with the Brazilian Pharmacopeia and revealed a good PZQ release profile in an acidic medium for the PMMA-DEAEMA copolymer, reaching values close to 100 % in less than 3 h. The in vivo pharmacokinetic analyses were conducted using free PZQ as the control group that was compared with the investigated matrices. The drug was administered orally at doses of 60 mg/kg, and the PMMA-co-DEAEMA copolymer microparticles were found to be the most efficient release system among the investigated ones, reaching a C_max value of 1007 ± 83 ng/mL, even higher than that observed for free PZQ, which displayed a C_max value of 432 ± 98 ng/mL.

The growing global concern over plastic waste accumulation has brought this issue to the forefront of environmental discussions. The increasing demand for plastic materials has led to the widespread production of plastic resins. However, the low cost of plastics, combined with high supply and consumption rates, has resulted in a troubling surge in post-consumer plastic waste. At the same time, the essential role plastics play in ensuring quality, convenience, and modern living has made them indispensable. In this context, the concept of circularity introduces a transformative shift in consumption habits, product design, and the management of raw materials and waste. A central strategy for promoting circularity in the plastics economy is the development of chemical recycling technologies. These processes aim to convert plastic waste into higher-value materials for the chemical industry, often generating liquid and gaseous products that can serve as feedstocks—ideally leading to the recovery of the original monomers. As polyolefins are the most widely used plastics worldwide, efficient recovery of their corresponding monomers is crucial to advancing circular strategies. This review explores current methods for the chemical depolymerization of polyolefins and critically analyzes efforts focused on the direct recovery of olefinic monomers.

The present study investigates the influence of extrusion pretreatment on the pyrolysis of post‐consumer polypropylene (PP), expanding upon previous findings related to the pyrolysis of polyethylene (PE, polymer engineering science, https://doi.org/10.1002/pen.27267 ). PP residues were extruded at 450°C for 2 min in a corotating twin‐screw extruder prior to pyrolysis under different conditions (425°C–475°C; 15–45 min). Results showed that extrusion pretreatment can significantly affect the feedstock properties, reducing average molar masses and polydispersity, which in turn can affect the thermal decomposition dynamics. As shown experimentally, the yields obtained after extrusion pretreatment of PP samples were different from the ones obtained before pretreatment, as the apparent activation energy for total yields was reduced after the proposed extrusion pretreatment. However, at higher temperatures and conversions, overall product yields and compositions were similar between the original and extruded samples, as the reaction mechanism remains essentially the same and observed differences are related mainly to the heat transfer dynamics. This is similar to results reported previously for HDPE, but is different from results obtained with LLDPE, reinforcing that the existence of long and complex chain branches can increase the sensitivity of the degradation behavior to temperature trajectories.

Chemical recycling of polyolefins is essential to mitigate plastic waste accumulation and promote circular economy strategies. Among the various chemical recycling pathways, catalytic pyrolysis, tandem catalyst systems, ethenolysis, hydrocracking, and hydrogenolysis have emerged as promising approaches for converting polyolefin waste into valuable hydrocarbons, including gaseous, liquid, and solid products. This review provides a survey of recent research on these methodologies, with a particular focus on the production of light gaseous hydrocarbons (C1–C4), bypassing the intermediate pyrolysis oil stage, which is often associated with contaminants and increased processing costs. The novelty of the present work lies in its emphasis on gaseous fractions, in contrast to most existing studies that primarily target oil recovery. Aspects such as catalyst selection, reaction conditions, and product distribution are analyzed. Additionally, the current Technology Readiness Level (TRL) of the studied processes, their relative advantages, limitations, and perspectives for industrial applications are discussed. The analysis highlights catalytic pyrolysis with zeolites as the most mature and scalable technological alternative for manufacture of light compounds directly from polyolefin waste, while tandem catalyst systems and ethenolysis constitute promising but still emerging alternatives for targeted gas production.

Chemical recycling of polyolefins is essential to mitigate plastic waste accumulation and promote circular economy strategies. Among the various chemical recycling pathways, catalytic pyrolysis, tandem catalyst systems, ethenolysis, hydrocracking, and hydrogenolysis have emerged as promising approaches for converting polyolefin waste into valuable hydrocarbons, including gaseous, liquid, and solid products. This review provides a comprehensive survey of recent research on these methodologies, with a particular focus on the production of light gaseous hydrocarbons (C2–C4), bypassing the intermediate pyrolysis oil stage, potentially reducing contamination issues and simplifying downstream processing. In contrast to conventional reviews focused primarily on liquid products, the present work emphasizes strategies for enhancing the selective production of light gaseous hydrocarbons due to their potential application in circular monomer manufacturing. Aspects such as catalyst selection, reaction conditions, and product distribution are analyzed. Additionally, the current Technology Readiness Level (TRL) of the studied processes and their relative advantages, limitations, and perspectives for industrial applications are discussed. The analysis highlights catalytic pyrolysis with zeolites as the most mature and scalable technological alternative for manufacture of light compounds directly from polyolefin waste, while tandem catalyst systems and ethenolysis constitute promising but still emerging alternatives for targeted gas production.