Learn More
The 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(More)
The influence of processing on the performance of carrier material used in dry powder inhalers was investigated. alpha-Lactose monohydrate crystals were processed by ball milling for cumulative time durations and their properties evaluated. As expected, milling reduced the median particle diameter while increasing fine particulate (<10 microm) and amorphous(More)
An atomic force microscope (AFM) colloid probe technique has been used to investigate the effect of relative humidity (RH) on the adhesion properties of pharmaceutical powder surfaces. The adhesion between a model substrate, alpha-lactose monohydrate, and model particulate drugs, salbutamol sulphate and budesonide, was investigated between RHs of 15 and(More)
The relationship between drug/lactose ratio and aerosolisation performance of conventional carrier based formulations was investigated using the twin stage impinger. A dose range of approximately 10-450 microg of drug in a 50 mg lactose carrier formulation was studied. Statistical differences in both the fine particle dose and fine particle fraction were(More)
Atomic force microscopy was used to investigate the influence of mechanical processing (milling) on the surface stability of salbutamol sulfate. Phase imaging, a development of tapping mode atomic force microscopy, was used to elucidate variations in the physico-mechanical properties on the surface of salbutamol sulfate crystals by measuring the phase lag(More)
Surface energy data for samples of microcrystalline cellulose have been obtained using two techniques: capillary intrusion and inverse gas chromatography. Ten microcrystalline cellulose materials, studied using capillary intrusion, showed significant differences in the measured surface energetics (in terms of total surface energy and the acid-base(More)
The aerosolization of salbutamol sulfate, measured as fine particle dose (FPD LD) and fine particle fraction (FPF LD) (<6.4 microm mass median aerodynamic diameter), from two sieved (63-90 microm) lactose monohydrate carriers, one as supplied, one smoothed by controlled surface dissolution, was studied. In general, no significant variation in FPD LD was(More)
Dynamic vapor sorption (DVS) was used to determine the moisture sorption properties of sodium starch glycolates. The results were compared to similarly obtained data for potato starch, pregelatinized starch, microcrystalline cellulose (MCC), and crystalline lactose. As expected, sodium starch glycolates exhibit a large mass gain at 90% relative humidity(More)
The compaction behavior of three "as supplied" commercially available grades of sodium starch glycolate (SSG), Explotab, Primojel, and Vivastar P, was investigated at compression speeds of 0.17 and 30 mm/sec. The results suggested that the three "as supplied" materials exhibit different compression and compaction behavior. Primojel and Explotab exhibited(More)
The successful manufacture of a regulatory approved dry powder inhaler (DPI) product is only achievable by applying robust control systems to all aspects of analytical, engineering, and material based processes. Whilst many aspects of DPI drug product manufacturing can be adequately controlled, it is often the control of materials, that is, drug substance(More)