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In order to provide asthmatic patients with an inhaler that does not use chlorofluorocarbon propellants, a novel multidose hand-held nebulizer (RESPIMAT, Boehringer Ingelheim Ltd.) has been developed. This device delivers 200 x 15 microL metered doses of drug solution, but does not use propellants of any kind. In this study of 10 healthy volunteers, the deposition pattern in the lungs and oropharynx of an ethanolic solution of flunisolide delivered via a prototype III multidose nebulizer has been determined by gamma scintigraphy. A comparison was made with the same dose (250 micrograms) of flunisolide delivered by a pressurized metered dose inhaler (MDI) and MDI plus Inhacort spacer. Mean (SD) whole lung deposition from the multidose nebulizer (39.7 (9.9) % of the metered dose) was significantly higher than that from either MDI (15.3 (5.1) %, P < 0.01) or MDI plus spacer (28.0 (7.0) %, P = 0.01). A mean 10.4% of the dose was recovered from an exhaled air filter for the multidose nebulizer, but less than 2% of the dose for MDI or MDI plus spacer. Oropharyngeal deposition was significantly reduced for the multidose nebulizer (39.9 (9.4) %) compared to MDI (66.9 (7.1) %), but was reduced further for the MDI plus spacer (27.3 (11.3) %). The multidose nebulizer delivers an unusually high percentage of an aerosol dose to the lungs, and it "targets" flunisolide to the lungs more effectively than the MDI. The multidose nebulizer could constitute a viable alternative to MDIs in asthma maintenance therapy.

Release of 5-ASA from a sustained release formulation (Pentasa, Ferring A/S, Copenhagen, Denmark) was monitored with plasma sampling for up to 24 hours in nine volunteers under both fasted and fed conditions. Drug absorption was correlated with location of the sustained-release microgranules in the gastrointestinal tract by gamma scintigraphy. Disintegration of the labeled tablet preparation occurred in the stomach within 20 minutes and acetylated 5-ASA was detectable in the plasma less than 60 minutes after ingestion. No significant differences were detected in either transit times through the small intestine, peak plasma acetylated 5-ASA concentration or lag time to absorption between fasted and fed individuals. Peak plasma concentration of acetylated 5-ASA usually occurred when the microgranules were present in the small intestine or ascending colon. The pharmacoscintigraphic study confirmed that 5-ASA release from the formulation occurred throughout the gastrointestinal tract, and that food effects on the in vivo behavior of the preparation were minimal.

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