The Science Journal of the American Association for Respiratory Care

1997 OPEN FORUM Abstracts

THROAT-MODEL DEPOSITION OF 20 MDI DRUGS, COMPARING THE MEDISPACER(r) WITH THE MANUFACTURER'S NOZZLE

David T. Sladek CRTT, Scott A. Foss BS, Thayer Medical Corporation, Tucson AZ

Background: Throat deposition is considered undesirable for drugs targeted to the lungs, as a concentration of the drug in the throat may cause side effects. All metered dose inhaler (MDI) canisters are offered with an aerosol delivery nozzle designed by the drug manufacturer. The Airlife^{TM} Hand Held MediSpacer has a universal nozzle designed for use with all MDI drugs. This laboratory study compares the deposition of 20 MDI drugs onto a throat model when administered in two different ways: with the manufacturer's nozzle or with the MediSpacer. Method: The throat model was in-line between the MDI delivery device and a vacuum pump (air flow rate 28 L/min). For nine of the drugs (marked below with *) a glass throat model was used; for the other 11 the throat model was the USP standard aluminum version. After multiple doses were administered, the throat model was rinsed and the amount of drug in the rinsings was quantified using standard UV spectroscopic techniques. Five tests were averaged for each drug/device combination. Results: The table compares the percentage of the total drug/dose found in the throat-model rinsings, using the MediSpacer (Medi) and the manufacturer's nozzle (Mfr). Total drug/dose is the nominal amount listed on the label.

Total % of total dose Total % of total dose

drug/ found in throat drug/ found in throat

Drug dose Medi Mfr Drug dose Medi Mfr

Steroid: Bronchodilator (cont.):

Aerobid* 250 µg 1.0% 39% Brethaire 0.20 mg 3.5% 85%

Azmacort 200 µg 7.0 8.5 Bronkaid 0.25 mg 0.6 57

Beclovent 42 µg 1.2 45 Isuprel 131 µg 0.8 61

Flovent 220 µg 1.4 40 Maxair* 0.2 mg 1.5 70

Vanceril* 42 µg 0.5 36 Medihaler- 0.08 mg 1.8 36

Iso

Anti-Inflammatory Primatene

(non-steroid): Mist 0.22 mg 0.7 65

Intal* 5 mg 12 76 Proventil 90 µg 4.4 52

Tilade 1.75 mg 1.0 62 Proventil

HFA 108 µg 5.6 44

Bronchodilator: Serevent* 21 µg 1.9 25

Alupent* 0.65 mg 2.2 63 Tornalate* 0.37 mg 1.4 32

Atrovent* 18 µg 2.7 14 Ventolin* 90 µg 4.4 53

Conclusion: For all drugs tested except Azmacort (whose nozzle has a built-in spacer), two-tailed t-tests show that these differences are statistically significant (p < 0.05). Spacers are usually not mentioned in the labeling of inhaled aerosol drugs; however, a spacer will clearly be effective in reducing throat deposition of the active ingredient. This may be particularly beneficial in the case of inhaled steroids, where throat deposition is known to lead to clinical complications.

OF-97-049

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