Presented in this work are the results of a study designed to investigate the impact of the valve metering chamber volume and actuator design on the aerodynamic particle size distribution (PSD) of a suspension metered dose inhaler (MDI) containing propellant HFA-227. It was hypothesized that the valve metering volume and the actuator design in the MDI could influence the PSD of the emitted dose since it would affect the aerosol spray dynamics. The PSD results from this study, measured using cascade impaction, revealed that samples containing an actuator intended for oral delivery (rectangular mouthpiece and orifice diameter of approximately 0.5 mm) produced a higher fine particle dose (FPD) than those containing an actuator intended for nasal delivery (circular nosetip and orifice diameter of approximately 1 mm). In addition, the drug PSD profile was shown to be more sensitive to differences in the particle size of the suspended material when the oral actuator was used compared to when the nasal actuator was used. The valve metering chamber (25 vs. 63 microL volume) did not appear to have a major effect on the product aerodynamic PSD or the droplet size. These results demonstrate the importance of actuator design and orifice size in determining the aerodynamic PSD of an MDI.

No abstract

Spray-dried skim milk, naturally contaminated with aflatoxin M„ was added to either raw or pasteurized whole milk to a final concentration of 1.1 Mg aflatoxin M,/L milk. Formalin (37% w/w) was added to the milk solutions to final concentrations of 0, 0.025, 0.05, and 0.1% formaldehyde. Samples were stored in the dark at 21°C in plastic and glass containers and were analyzed for aflatoxin M, at 0,1, 2, 3, and 4 weeks. This experiment was repeated using only raw milk and glass containers. Aflatoxin M, analyses were done at 0, 1, and 2 weeks. Aflatoxin M, losses increased over time and with increased formaldehyde concentration. With both experiments, aflatoxin M, levels after 2 weeks were less than 0.05 iigfL in samples containing 0.1% formaldehyde.

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