Effects of Geomaterial-Originated Fillers on Microstructure and Mechanical/Physical Properties of α- and β-Chitosan-Based Films

Edible films and coatings with good mechanical/physical properties are highly required for carrying medical substances and food packaging. So, solvent-cast films of α- or β-chitosan filled with palygorskite, montmorillonite or geopolymer-containing material (GCM), were prepared, and the effects of their clay contents (up to 50 wt.%) on the mechanical/physical properties were assessed. The microstructure of the films was investigated using FT-IR spectroscopy, SEM and thermal analysis. The results showed that, except for the films composed of GCM and β-chitosan, the mechanical properties of the films with limited (up to 5 wt.%) to moderate (5–25 wt.%) amounts of fillers increased as a result of the attractive electrostatic forces formed between the fillers and chitosan functional groups (–NH3+, CH2OH and NHCOCH3). However, due to the occurrence of coarse aggregates, the strength of filler-rich films declined. The addition of fillers led to an increase in porosity and water absorption of the films, but it had irregular effects on their wettability and water vapor transmission rate. These observations as well as the thermal stability of the films were discussed in relation to the characterization results.

A comparison between solvent casting and electrospinning methods for the fabrication of neem extract-containing buccal films

In the present study a double layer mucoadhesive buccal film containing nanocarriers encapsulated with neem extract was fabricated through electrospinning and solvent casting techniques for dental therapeutic applications. The morphological, physical and mucoadhesive properties of the resulting electrospun and solvent cast oral films were mutually compared, and their drug release behavior and antibacterial activity were further investigated. Chitosan/poly(vinylalcohol) (PVA) as a mucoadhesive component and phenylalanine amino acid nanotubes (PhNTs)-containing neem extract as a drug nanocarrier were used to fabricate oral films. A poly(caprolactone) (PCL) layer was used as an impermeable backing layer to protect the mucoadhesive component from tongue movement and drug loss. The results indicated an interconnected porous and fully filled solid structures for electrospun and solvent cast films, respectively. The physicomechanical parameters of the samples such as pH, weight, thickness, folding endurance and tensile strength were also evaluated. The crosslinked electrospun buccal film indicated better swelling and mucoadhesive properties compared to the solvent cast film. In addition, the drug loading capacity and encapsulation efficiency of the solvent cast film showed lower experimental values than those of electrospun oral film. On the other hand, the electrospun oral film had a well-controlled release of neem extract up to 82% at oral pH, which is best fitted to the Weibull model, and demonstrated the highest antibacterial properties against S. mutans bacteria with high biocompatibility on L929 fibroblast cells. Generally, the synthesized electrospun mucoadhesive film has a better potential for oral therapeutic applications than the solvent cast film.

Solvent-cast polymeric films from pectin and Eudragit® NE 30D for transdermal drug delivery systems

In this study, solvent-cast polymeric films containing ionic liquid lidocaine/aspirin for transdermal patches were developed. Solvent-cast polymeric films were prepared from two polymers, pectin and Eudragit® NE 30D, by drying the polymeric solution in a hot air oven at 70 ± 3°C for 10 hrs. Glycerin was used as a plasticizer. Lidocaine and aspirin were prepared in ionic liquid form and loaded into the patches. The physicomechanical properties of the films were characterized by texture analysis, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction. A scanning electron microscope was used to photograph the surfaces of solvent-cast polymeric films. Eudragit® NE 30D significantly decreased the toughness and rigidity of the films. The transdermal patches were in the amorphous state, and their thermal properties were not changed from blank polymeric films. The surfaces of transdermal patches were rougher than blank polymeric films and revealed the distribution of the drug. Eudragit® NE 30D significantly decreased the trends of entrapment efficiency and in vitro release of lidocaine and aspirin drugs. The kinetic release observed in vitro fitted to Higuchi’s model rather than zero and first order models, indicating that a diffusion mechanism governed the release of the drug from the patch. Thus, the solvent-cast polymeric films from two polymers, pectin and Eudragit® NE 30D, are suitable for transdermal patches loaded with ionic liquid lidocaine/aspirin.