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The venlafaxine hydrochloride (VHL)-loaded chitosan nanoparticles were prepared by ionic gelation of chitosan (CS) using tripolyphosphate (TPP). The nanoparticles were characterized using FTIR, differential scanning calorimetry, X-ray diffraction, dynamic light scattering, transmission electron microscopy, and X-ray photoelectron spectroscopy. The effect of concentration of CS, polyethylene glycol (PEG), VHL and CS/TPP mass ratio on the particle size and zeta potential of nanoparticles was examined. The particle size of CS/TPP nanoparticles and VHL-loaded CS/TPP nanoparticles was within the range of 200-400 nm with positive surface charge. In the case of VHL-loaded nanoparticles and PEG-coated CS/TPP nanoparticles, the particle size increases and surface charge decreases with increasing concentration of VHL and PEG. Both placebo and VHL-loaded CS/TPP nanoparticles were observed to be spherical in nature. PEG coating on the surface of CS/TPP nanoparticles was confirmed by XPS analysis. Maximum drug entrapment efficiency (70%) was observed at 0.6 mg/mL drug concentration. In vitro drug release study at 37 C AE 0.5 C and pH 7.4 exhibited initial burst release followed by a steady release.

Studies on the use of natural fibers as replacement to man-made fiber in fiber-reinforced co mposites have increased and opened up further industrial possibilities. Natural fibers have the advantages of low density, low cost, and biodegradability. However, the main d isadvantages of natural fibers in co mposites are the poor co mpatibility between fiber and matrix and the relative high mo isture sorption. Therefore, chemical treat ments are considered in modify ing the fiber surface properties. In this study, Sisal fibers were modified using alkali and benzoyl pero xide solution of different concentration for different time intervals. Morphological changes, thermal stability and crystallinity of fibers were investigated using scanning electron microscope (SEM), TGA and XRD technique. Thermal stability of sisal fibers were decreased on mercerization. Whereas, sisal fibers treated with benzoyl pero xide the enhanced thermal stability. In case of XRD studies, sisal fibers show enhanced crystallin ity.

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