Using a novel NMR option, magic angle spinning pulsed field gradient (MAS PFG) NMR, the mobility of aliphatic domains in humic substances in the presence of toluene (about 4.5 wt. %) has been monitored.
View Article and Find Full Text PDFThe relationships between the physicochemical properties and functionality in dry powder inhaler (DPI) performance was investigated for inhalation grade anhydrous lactose and compared to monohydrate grades. The excipients were characterised using a range of techniques including particle size analysis, moisture sorption and powder rheometry. The inhalation anhydrous lactose grades were readily characterisable.
View Article and Find Full Text PDFPurpose: To investigate the role of in situ generated fine excipient particles on the fluidization and aerosolization properties of dry powder inhaler (DPI) formulations.
Materials And Methods: Carrier based DPI formulations were prepared under low and high shear blending. Powder rheometery was utilized to measure bulk powder properties in a consolidated and aerated state.
The behaviour of dry powder blends for inhalation, depending on the amount of fine lactose particles smaller than 10microm and the presence of magnesium stearate (MgSt), was studied in this work. A laser light diffraction method was developed to determine accurately size and volume fraction of these fine lactose particles in coarse carrier lactose (x(50) approximately 220microm). A linear relationship between measured volume fraction undersize at 10microm Q(3)(10microm) and added fine lactose could be established.
View Article and Find Full Text PDFThe influence of the size and shape of paracetamol particles on the flow and compression behavior of blends (1:1) of microcrystalline cellulose (MCC) was investigated. The effect of paracetamol particle shape was investigated by using two differently prepared samples, micronized and novel engineered Solution Atomization and Xstallization by Sonication (SAXS) particles, which exhibited similar particle size ranges (2-6 microm). The results were compared to data obtained for an untreated paracetamol sample.
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