Lung Deposition of Fenoterol and Flunisolide Delivered Using a Novel Device for Inhaled Medicines: Radioactivity Recovered From Exhaled Air
In the fenoterol study, only a small percentage of the metered dose from each device was detected in the exhaled air (ie, on the exhalation filter and nose plugs) as shown in Table 3. However, the mean percentage of the dose in exhaled air for the RESPIMAT device was significantly greater than that for the MDI (p<0.02) and the MDI with Aerochamber (p<0.01).
For the subjects receiving flunisolide via the MDI with spacer, the mean percentage of the dose detected in the exhaled air was very low (0.4%). In comparison, both the RESPIMAT and the RESPIMAT with baffle deposited a significantly greater proportion of the dose in the exhaled air (mean 12.4% and 7.4%, respectively; p<0.01) as shown in Table 4.
There was no evidence in either study of any paradoxical bronchoconstriction in subjects receiving fenot-erol or flunisolide. This is an important observation since the formulations include either the preservative benzalkonium chloride or ethanolic solutions. FEV1 values before and after dosing for each of the study regimens are shown in Table 5. Otherwise reported adverse events in these studies were unremarkable and reflected the known effects of fenoterol and flunisolide. One subject in the fenoterol study developed generalized tremor immediately after dosing on two of the study days, accompanied by tachycardia on one occasion. Both events resolved spontaneously. buy yasmin online
To achieve good control of obstructive airway diseases, there must be adequate delivery of inhaled bronchodilator drugs to the lungs. However, because many patients have difficulties using currently available inhaler devices correctly, there have been intense efforts to develop inhaler devices that are easy to use and provide improved lung deposition. Ideally, an inhaler device should be able to deliver a range of drugs, including bronchodilators or corticosteroids, so that patients only have to learn how to handle one type of device. For this reason, two studies that investigated the drug deposition of fenoterol and flunisolide delivered by a novel “soft mist inhaler” device, the RESPIMAT, have been presented together in this article. Gamma scintigraphy is a useful method for obtaining information on in vivo drug deposition from inhaler devices. The technique not only gives a visual picture of where the inhaled drug has been deposited, but also provides accurate quantitative information on the distribution of drug within the lungs and in the oropharynx.
Table 5—Predose and 60-min Postdose Values of FEVj for Subjects Inhaling Fenoterol and Flunisolide
|RESPIMAT||3.69 (0.74)||3.84 (0.90)|
|MDI with Aerochamber||3.77 (0.87)||3.92 (0.99)|
|RESPIMAT||3.53 (0.74)||3.5 (0.76)|
|RESPIMAT (baffle)||3.61 (0.76)||3.65 (0.80)|
|MDI with spacer||3.56 (0.82)||3.66 (0.81)|