药物信息为FLOVENT DISKUS 50 mcg (fluticasone propionate inhalation powder, 50 mcg) For Oral Inhalation Only (GlaxoSmithKline): DESCRIPTION

The active component of FLOVENT DISKUS is fluticasone propionate, a corticosteroid having the chemical name S-(fluoromethyl) 6α,9-difluoro-11β,17-dihydroxy-16α-methyl-3-oxoandrosta-1,4-diene-17β-carbothioate, 17-propionate and the following chemical structure:

Fluticasone propionate is a white powder with a molecular weight of 500.6, and the empirical formula is C₂₅H₃₁F₃O₅S. It is practically insoluble in water, freely soluble in dimethyl sulfoxide and dimethylformamide, and slightly soluble in methanol and 95% ethanol.

FLOVENT DISKUS is a specially designed plastic inhalation delivery system containing a double-foil blister strip of a powder formulation of fluticasone propionate intended for oral inhalation only. The DISKUS^® inhalation unit, which is the delivery component, is an integral part of the drug product. Each blister on the double-foil strip within the unit contains 50 mcg of microfine fluticasone propionate in 12.5 mg of formulation containing lactose (which contains milk proteins). After a blister containing medication is opened by activating the DISKUS, the medication is dispersed into the airstream created by the patient inhaling through the mouthpiece.

Under standardized in vitro test conditions, FLOVENT DISKUS 50 mcg delivers 46 mcg of fluticasone propionate when tested at a flow rate of 60 L/min for 2 seconds. In adult patients with obstructive lung disease and severely compromised lung function (mean forced expiratory volume in 1 second [FEV₁] 20% to 30% of predicted), mean peak inspiratory flow (PIF) through a DISKUS^® was 82.4 L/min (range, 46.1 to 115.3 L/min). In children with asthma 4 and 8 years old, mean PIF through FLOVENT DISKUS was 70 and 104 L/min, respectively (range, 48 to 123 L/min).

The actual amount of drug delivered to the lung may depend on patient factors, such as inspiratory flow profile.