Microencapsulation of fish oil by casein-pectin complexes and gum arabic microparticles: oxidative stabilisation.

This study was aimed to microencapsulate fish oil (FO) in two biocompatible polymeric blends: gum arabic (GA)-maltodextrin (MD) and casein-pectin (CP)-MD. GA-MD microparticles and CP-MD microparticles were produced by spray-drying and complex coacervation and spray-drying, respectively. Encapsulation efficiency, particle size, moisture content, oxidative stability, and morphological properties were analysed. Encapsulation efficiencies of 51.2-56.8% (w/v) for GA and 64.7-67.9% (w/v) for CP preparations were found. GA particle sizes varied from 2 to 100 µm and from 2 to 120 µm for CP microparticles. Spherical forms with depressions in the topography of both systems were evidenced by scanning electron microscopy. Confocal microscopy evidenced surface oil on GA microparticles, corroborating encapsulation efficiency. CP was more efficient than GA to reduce oxidation, with maximum peroxide values (PVs) of 17.40 mmol/kg oil after 28 d at 40 °C/75% relative humidity (RH). Thus, CP is a promising biopolymeric blend for encapsulation of FO that provides protection against lipid oxidation.

Chitosan-based mucoadhesive films containing 5-aminolevulinic acid for buccal cancer's treatment.

Photodynamic therapy (PDT) is a relatively new method to treat various kinds of tumors, including those of the oral cavity. The topical 5-ALA-PDT treatment for tumors of the oral mucosa is preferred, since when administered systemically, there is a general photosensitization drawback in the patient. However, 5-ALA is a hydrophilic molecule and its penetration and retention is limited by topical route, including oral mucosa. We propose a topical delivery system of chitosan-based mucoadhesive film, aiming to promote greater retention of 5-ALA in tissue. The chitosan (CHT) films (4% w/w) were prepared using the solvent evaporation/casting technique. They were tested without 5-ALA resulting in permeability to water vapor (W.V.P=2.15-8.54 g mm/(h cm(2)Pa) swelling ∼300.0% (±10.5) at 4 h or 24 h and in vitro residence time >24 h for all tests. CHT films containing 10.0% (w/w) 5-ALA have resulted in average weight of 0.22 g and thickness of 0.608 mm as suitable characteristics for oral application. In the presence of CHT films both in vitro permeation and retention of 5-ALA (1.0% or 10.0%) were increased. However, 10.0% 5-ALA presented highest values of permeation and retention (∼4 and 17 times respectively, compared to propylene glycol vehicle). On the other hand, in vitro mucoadhesion of CHT films was decreased (18.2-fold and 3.1-fold) by 5-ALA addition (1.0% or 10.0% respectively). However, CHT film containing 10.0% of 5-ALA can be a potential delivery system for topical use in the treatment of tumors of the oral cavity using PDT because it favored the retention of 5-ALA in this tissue and has shown convenient mucoadhesion.