ABSTRACT
The preparation of chitosan nanoparticles in combination with pectins, as additional mucoadhesive biopolymers, was investigated. Pectins from apple and from citrus fruit were considered; polygalacturonic acid was taken as a reference. Tripolyphosphate was used as an anionic cross-linker. Two different techniques were compared, namely the coating and the blending. Coated nanoparticles (NPs) in the ratio pectin:NPs from 2:1 to 5:1 evidenced that the size of NPs increased as the amount of pectin (both from apple and citrus fruit) was increased. In particular, for NPs coated with pectin from citrus fruit the size ranges from 200 to 260nm; while for NPs coated with pectin from apple the size ranges from 330 to 450nm. A minimum value of Z-potential around -35mV was obtained for the ratio pectin:NPs 4:1, while further addition of pectin did not decrease the Z-potential. Also blended NPs showed a dependence of the size on the ratio of the components: for a given ratio pectin:tripolyphosphate the size increases as the fraction of chitosan increases; for a low ratio chitosan:pectin a high amount of tripolyphosphate was needed to obtain a compact structure. The effect of the additional presence of loaded proteins in chitosan-pectin nanoparticles was also investigated, since proteins contribute to alter the electrostatic interactions among charged species. FT-IR and DSC characterization are presented to confirm the interactions between biopolymers. Finally, the biocompatibility of the used materials was assessed by the chorioallantoic membrane assay, confirming the safety of the materials.
Subject(s)
Chitosan/chemistry , Nanoparticles/chemistry , Pectins/chemistry , Animals , Chick Embryo , Chitosan/administration & dosage , Chorioallantoic Membrane/drug effects , Drug Compounding/methods , Nanoparticles/administration & dosage , Ovalbumin/chemistry , Pectins/administration & dosage , Serum Albumin, Bovine/chemistryABSTRACT
The process of quasi-isothermal dehydration of thin films of pure water and aqueous sugar solutions is investigated with a dual experimental and theoretical approach. A nanoporous paper disk with a homogeneous internal structure was used as a substrate. This experimental set-up makes it possible to gather thermodynamic data under well-defined conditions, develop a numerical model, and extract needed information about the dehydration process, in particular the water activity. It is found that the temperature evolution of the pure water film is not strictly isothermal during the drying process, possibly due to the influence of water diffusion through the cellulose web of the substrate. The role of sugar is clearly detectable and its influence on the dehydration process can be identified. At the end of the drying process, trehalose molecules slow down the diffusion of water molecules through the substrate in a more pronounced way than do the glucose molecules.
Subject(s)
Cellulose/chemistry , Glucose/chemistry , Temperature , Trehalose/chemistry , Water/chemistry , Dehydration , Diffusion , Solutions , ThermodynamicsABSTRACT
The nanoemulsified composite (NEC) delivery system is a patented technology based on the incorporation of a double microemulsion into microporous carrier. This approach was applied on the very water insoluble ubidecarenone drug. The resulting composite powder showed good technological properties such as flowability; also good stability was evidentiated, with size of the nano-droplets released from the systems maintained equal to the starting size also after a long storage. Furthermore very good biopharmaceutical properties were originated, with water solubility concentrations up to 50-fold higher than pure ubidecarenone and oral absorption in rats up to three-fold greater than standard commercial products in terms of plasma levels and AUC.
