Hydroxypropyl methylcellulose (HPMC; 5%, 6%, and 7% w/w) and Carbopol 934 (1% w/w) hydrogels containing DFS-CS microspheres equivalent to 1% w/w active drug were prepared. The physicochemical characterization revealed that all hydrogels had a suitable pH for rectal application (6.5-7.4). The consistency of HPMC hydrogels showed direct proportionality Go6983 to the concentration of the gelling agent, while carbopol 934 gel showed its difficulty for rectal administration. Farrow’s constant for all hydrogels were greater than one indicating pseudoplastic flow. In vitro drug release from the mucoadhesive hydrogel formulations showed a controlled drug release
pattern, reaching 34.6-39.7% after 6 h. The kinetic analysis of the release
data revealed that zero-order was the prominent release mechanism. The mucoadhesion time of 7% w/w HPMC hydrogel was 330 min, allowing the loaded microspheres to be attached to the surface of rectal mucosa. Histopathological examination demonstrated the lowest irritant response to the hydrogel loaded with DFS-CS microspheres in response to other forms of the drug.”
“Photosensitization of singlet oxygen generation in porous silicon (PSi) was investigated by simultaneous measurements of the photoluminescence (PL) of silicon nanocrystals (nc-Si) and the infrared emission of the (1)Delta-state of oxygen molecules at 1270 nm (0.98 eV) at room temperature. Photodegradation of the nc-Si PL properties was found to correlate with the efficiency of singlet oxygen generation. The quantum efficiency of singlet oxygen generation in PSi was
CP-673451 Protein Tyrosine Kinase inhibitor estimated to be about 1%, while the lifetime of singlet oxygen was about fifteen ms. The kinetics of nc-Si PL intensity under cw excitation undergoes a power law dependence with the exponent dependent on the photon energy of luminescence. The experimental results are explained with a model of photodegradation controlled by the diffusion of singlet oxygen molecules in a disordered structure of porous silicon. (C) 2011 American Institute of Physics. [doi:10.1063/1.3586044]“
“The injection-molded specimens of neat HDPE and the PET/HDPE blends were prepared by conventional injection molding (CIM) and by pressure vibration injection GSK2879552 inhibitor molding (PVIM), respectively. The effect of oscillation pressure and PET phase with different shapes on superstructure and its crystal orientation distribution of injection molded samples were characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and two-dimension wide-angle X-ray diffraction techniques (2D-WAXD). Hermans’ orientation functions were determined from the wide-angle X-ray diffraction patterns. With the PET particles added, the shear viscosity of blend increase and crystallization rate of HDPE phase is enhanced.