Phosphated crosslinked pectin as a potential excipient for specific drug delivery: preparation and physicochemical characterization

Abstract

Pectin was chemically modified with different amounts of trisodium trimetaphosphate (STMP) in aqueous solution (pH = 12), thereby giving a material with reduced water solubility. The physiochemical characterization of this new material was carried out through Fourier transform infrared and thermogravimetric analyses. Phosphated pectin (Pect-STMP) together with prebiotic (oligosaccharide) were incorporated into an aqueous dispersion of polymethacrylate (Eudragit  RS 30 D) in order to obtain free films using a casting process (50 • C) on a Teflon plate. The free films were evaluated using water vapour transmission, average swelling index in simulated gastric fluid (SGF) and simulated intestinal fluid, scanning electron microscopy and a diffusion study with theophylline in buffer solution with and without pectinolytic enzyme. The results suggest that the new material can be used in the coating process for oral solid-reservoir systems, to prevent the premature release of drugs in SGF (pH = 1.2). Furthermore, the presence of both Pect-STMP and oligosaccharide favours the specific degradation of the pellicle by the action of the enzymes produced by colonic microflora. The material obtained in this work has the potential to be applied in devices for drug delivery in the colon, making possible modified release of drugs. Nevertheless, subsequent colon-specific experiments in vivo need to be carried out in order to confirm the possible application of this new material.

Optimization of Pomegranate Peel Fibers Reinforced With Polyvinyl Alcohol Biocomposite Film Using Response Surface Methodology

“…The endothermic reaction is because of the water loss during the process of crystallization, which destroys the compound partially, that results increase in surface area, and promotes further thermal decomposition easier. For the optimized film the initial degradation starts around 100ºC, which indicates the evaporation of moisture, thermal degradation peak was observed around 250ºC and the loss of mass was around 42.8%, which is greater than the thermal degradation of natural pectin films which was around 219ºC as observed in literature 15 , this indicates the increase in the thermal stability of the pomegranate peel fibres reinforced with polyvinyl alcohol biocomposite film, which may be due to structural reorganization of polymers occurred during alkaline treatments of fibres 16 . In the final degradation phase, 34% of the residual mass was completely degraded around 800ºC, which indicates that the sample has high thermal stability.…”

Development and characterization of cross-linked gellan gum and retrograded starch blend hydrogels for drug delivery applications

“…Additionally, our results demonstrate that in the ionic cross-linking, the presence of cations can decrease the repulsion of anionic polymeric chains by increasing the amount of intra and/or interchain junction zones (Bajpai et al, 2008;Oliveira et al, 2010;Prezotti et al, 2014;Souto-Maior et al, 2010). This allows the building of a more dense and compact network, contributing to the higher hardness of IC hydrogels.…”

Standardization of Nanoparticle Characterization: Methods for Testing Properties, Stability, and Functionality of Edible Nanoparticles

“…One difficulty in accurately simulating the human colon is the considerable person-to-person variations in bacterial populations that exist. Rather than using bacteria, it is possible to formulate SCF containing a cocktail of enzymes typically produced by colonic bacteria e.g., glycosidases to (Souto-Maior et al, 2009;Yang, 2008).…”