pectins and shellac

Different types of polymers are widely used in biomedical, pharmaceutical and cosmetic purposes. Their applications are curbed, if the polymers can not break down by the body or if the polymer itself is harmful or decompose to harmful material. Authors provide an overview of different types of pharmaceutical polymers of various sources, of the structural characterization and possibilities of their chemical modification and of the classical and instrumental analytical examination methods. The paper deals with the limitations of the use of biopolymers, as well.

Topics: Acetylglucosamine; Agar; Alginates; Animals; Biocompatible Materials; Cellulose; Chondrus; Collagen; Galactans; Humans; Hyaluronic Acid; Lactic Acid; Mannans; Pectins; Plant Gums; Polyesters; Polyhydroxyalkanoates; Polymers; Resins, Plant; Starch

The aim of this investigation was to develop the high moisture protective ability and stable pectin through the design of composite films based on varying shellac concentrations. A film casting method was applied to prepare a free film. The moisture protective properties and mechanical properties were investigated. The findings was the composite films exhibited the reductions in the hydrophilicity, water vapor permeability, and the moisture content compared with pectin films. The single and composite films were then study for their stability at 40 °C and 75% RH for 90 d. Among the concentrations of shellac, 50% (w/w) could improve stability in terms of moisture protection after 90 d of storage, whereas lower concentrations of shellac (10% to 40%) could not achieve this. However, the higher shellac content also contributed to weaker mechanical properties. The mechanical improvement and stability of composite films with the incorporation of plasticizers were further investigated. Polyethylene glycol 400 and diethyl phthalate at a concentration of 10% were used. The results indicated that both plasticizers could enhance the mechanical characteristics and had a slight effect on moisture protection. The stability of pectin in terms of moisture protective properties could, therefore, be modified through the fabrication of composite films with hydrophobic polymers, that is, shellac and the addition of proper plasticizers to enhance mechanical properties, which could offer wide applications for edible film in food, agro, and pharmaceutical industries.. The composite film with 50% shellac could improve moisture protective properties of pectin film. Adding a plasticizer could build up the higher mechanical characteristics of composite film. Stability of pectin could be modified by fabrication of composite films with proper content of shellac and plasticizer.

Topics: Pectins; Permeability; Plasticizers; Polyethylene Glycols; Polymers; Resins, Plant

Microscopic capsules made from polysaccharides are used as carriers for drugs and food additives. Here, we use NMR microscopy to assess the permeability of capsule membranes and their stability under different environmental conditions. The results allow us to determine the suitability of different capsules for controlled drug delivery. As a measure of the membrane permeability, we monitor the diffusion of paramagnetic molecules into the microcapsules by dynamic NMR microimaging. We obtained the diffusion coefficients of the probe molecules in the membranes and in the capsule core by comparing the measured time dependent concentration maps with numerical solutions of the diffusion equation. The results reveal that external coatings strongly decrease the permeability of the capsules. In addition, we also visualized that the capsules are stable under gastric conditions but dissolve under simulated colonic conditions, as required for targeted drug delivery. Depending on the capsule, the timescales for these processes range from 1 to 28 h.

Topics: Algorithms; Anthocyanins; Capsules; Colon; Contrast Media; Delayed-Action Preparations; Diffusion; Drug Compounding; Drug Delivery Systems; Drug Stability; Excipients; Gastric Mucosa; Intestine, Small; Magnetic Resonance Imaging; Membranes, Artificial; Microscopy; Particle Size; Pectins; Permeability; Resins, Plant; Solubility; Stomach

This paper describes the mechanical properties of thin-walled, liquid-filled composite capsules consisting of calcium pectinate and shellac. In a series of experiments we measured the deformation of these particles in a spinning drop apparatus. For different pH-values we studied the elastic properties of these particles and compared the obtained results with the mechanical response measured by squeezing capsule experiments. In analogy to these experiments, we also investigated liquid-filled unloaded calcium pectinate capsules without the addition of shellac. The deformation properties of these experiments and the surface Young moduli were in good agreement. Furthermore we investigated the liquid-filled calcium pectinate and the composite capsules by NMR microscopy. These experiments allowed investigations of the membrane thickness and the kinetics of membrane growing. Additional characterizations by stress controlled small amplitude surface shear experiments of similar composed gel layers provided coherent results for the surface Young modulus.

Topics: Capsules; Hydrogen-Ion Concentration; Mechanical Phenomena; Membranes, Artificial; Microscopy; Pectins; Resins, Plant; Rheology

Anthocyanins are connected with various biological activities. A promising way to enhance the availability of anthocyanins for in situ effects in the lower intestine is colon-specific delivery.. Shellac and shellac/hydroxypropyl methylcellulose (HPMC) coated anthocyanin amidated pectin beads as dietary colonic delivery systems were successfully prepared by ionotropic gelation and fluid bed Wurster coating with aqueous shellac solution. Release characteristics, studied in vitro and ex vivo using simulated gastric fluid (SGF), ileostomy fluid and colostomy fluid (CF) revealed a retardation of anthocyanins during simulated passage of stomach and ileum as well as the desired release of pigments in the colon. Coating level was identified as an important parameter. By addition of 5 or 15% of the water-soluble polysaccharide HPMC to the shellac film, resistance in SGF was increased due to the plasticizer properties of the polymer. Incorporation of 15% HPMC (w/w based on shellac) into the shellac film additionally led to increased anthocyanin diffusivity and complete release as well as degradation of the formulation in CF.. In the used in vitro and ex vivo model system mimicking the human intestinal transit, the potential of shellac and shellac/HPMC coated anthocyanin amidated pectin beads as dietary colon targeting systems was demonstrated.

Topics: Adult; Aged; Anthocyanins; Chemistry, Pharmaceutical; Colon; Drug Delivery Systems; Humans; Hypromellose Derivatives; Intestinal Mucosa; Methylcellulose; Microscopy, Electron, Scanning; Pectins; Pharmaceutical Solutions; Polymers; Resins, Plant; Solubility