Organic Polymers for Encapsulation of Drugs, Food Ingredients and Agrochemicals

International audienc

Plant-animal extracts and biocompatible polymers forming oil-in-water emulsions: Formulations for food and pharmaceutical industries

The development of formulations from plant or animal extracts and polymeric platforms has been well established toward emulsion-based delivery systems, avoiding the use of conventional surfactants. This approach involves the stabilization of poorly water-soluble extracts by polymers, improving their dispersion into food and pharmaceutical products, avoiding premature degradation, and resulting in better bioavailability. According to the literature, extracts are obtained via conventional and novel methods, which exhibit advantages and disadvantages related to using organic solvent, temperature, time, pressure, and equipment cost. Similarly, for polymer-based emulsifiers, there are different methods to obtain them. Also, their chemical composition and morphology (linear, branched, and crosslinked) play relevant roles in their performance as stabilizing agents. On the other hand, oil-in-water emulsions from plant-animal extracts and biocompatible polymers have been prepared using different strategies focused on achieving high stability of the colloidal system. Hence, this review provides current information regarding some protocols used for the extraction/synthesis of materials and the development of promising formulations

Environment-Friendly Approach toward the Treatment of Raw Agricultural Wastewater and River Water via Flocculation Using Chitosan and Bean Straw Flour as Bioflocculants

International audienc

Loading and Release of Phenolic Compounds Present in Mexican Oregano (Lippia graveolens) in Different Chitosan Bio-Polymeric Cationic Matrixes

Mexican oregano (Lippia graveolens) polyphenols have antioxidant and anti-inflammatory potential, but low bioaccessibility. Therefore, in the present work the micro/nano-encapsulation of these compounds in two different matrixes of chitosan (CS) and chitosan-b-poly(PEGMA2000) (CS-b-PPEGMA) is described and assessed. The particle sizes of matrixes of CS (~955 nm) and CS-b-PPEGMA (~190 nm) increased by 10% and 50%, respectively, when the phenolic compounds were encapsulated, yielding loading efficiencies (LE) between 90–99% and 50–60%, correspondingly. The release profiles in simulated fluids revealed a better control of host–guest interactions by using the CS-b-PPEGMA matrix, reaching phenolic compounds release of 80% after 24 h, while single CS retained the guest compounds. The total reducing capacity (TRC) and Trolox equivalent antioxidant capacity (TEAC) of the phenolic compounds (PPHs) are protected and increased (more than five times) when they are encapsulated. Thus, this investigation provides a standard encapsulation strategy and relevant results regarding nutraceuticals stabilization and their improved bioaccessibility

Microwave-assisted synthesis of benzoxazinediones under solvent-free conditions

<p>Benzoxazinediones exhibit potential as versatile synthons in the synthesis of wide variety of heterocyclic compounds with biological activity. In this work, an efficient and eco-friendly one-step synthesis of benzoxazine-2,4-diones from phthalic anhydrides derivatives and trimethylsilyl azide using the microwave technique was developed and compared with conventional heating. Microwave irradiation plays a critical role in driving the reaction and providing access to products and/or regioisomers not available from conventional heating. Thus, the regioselectivity of the reaction may be modulated by the irradiation time. Depending on the method employed the benzoxazinediones were isolated with yields in the range of 30–90%.</p

Characterization and treatment of industrial laundry wastewaters: a review

International audienceThe industrial laundry sector is a major user of water and chemicals such as surfactants, and one of the largest producers of wastewater. Although treated wastewaters comply with regulations, they still contain contaminants. Here we review laundry wastewater with focus on industrial laundry activities and their challenges, chemical composition of wastewater, and treatment techniques. We discuss advantages and drawbacks of treatment techniques that can be used as secondary treatment in already existing plants, or as tertiary treatment, i.e., complementary to an existing treatment. We observe that laundry is an expanding industrial sector with increasing water requirements, an abundant use of chemical substances, and increasingly stringent discharge regulations. There is a lack of chemical and biological knowledge on aqueous discharges. Moreover, the chemical composition, temporal variability, treatment information, and environmental and ecotoxicological data are poorly reported. The composition of wastewaters and additives, and their temporal variability are also poorly known. Similarly, detailed information on treatments is rare, and environmental and ecotoxicological data are poorly reported. Finding a tertiary water treatment process that is efficient, viable, and environmentally friendly is challenging since wastewater volumes are very high and contaminants are present at trace level in complex organo mineral mixtures

A Comprehensive Study of Coke Deposits on a Pt-Sn/SBA-16 Catalyst during the Dehydrogenation of Propane

Catalytic propane dehydrogenation is an attractive method to produce propylene while avoiding the issues of its traditional synthesis via naphtha steam cracking of naphtha. In this contribution, a series of Pt-Sn/SBA-16 catalysts were synthesized and evaluated for this purpose. Bimetallic Pt-Sn catalysts were more active than catalysts containing only Pt. The catalyst with the best performance was assessed at different reaction times of 0, 60, 180, and 300 min. The evolution of coke deposits was also studied. Thermogravimetric analysis demonstrated the presence of two types of coke on the catalyst surface at low and high temperature, respectively. Raman results showed an increased coke&rsquo;s crystal size from 60 to 180 min on stream, and from 180 to 300 min under reaction, Raman suggested a reduction in the crystal size of coke. Also transmission electron microscopy confirmed a more evident agglomeration of metallic particles with reaction times higher than 180 min. These results are consistent with the phenomena called &ldquo;coke migration&rdquo; and the cause is often explained by coke movement near the particle to the support; it can also be explained due to sintering of the metallic particle, which we propose as a more suitable explanation