stability of suspensions and valve performance these include lecithins disodium dioctylsulphosuccinate oleic acid and sorbitan esters cosolvents may also be added to improve solubility of surfactant in propellant or modify the pharmacological performance these include alcohols and glycols e g ethanol isopropylalcohol glycerol propylene glycol polyethylene glycol etc or mixtures thereof further excipients may be added to improve performance or taste e g fatty acids and salts thereof such as magnesium stearate menthol oil etc dry powder inhalers include devices which meter the drugs from a chamber within the device or those that deliver pre metered doses utilizing gelatin plastic or other capsules cartridges or blister packs and or strips furthermore the two active ingredients of the present compositions i e compounds of formula i and u03b2 2 adrenergic agonists may be administered simultaneously in a single dosage form or they may be separately but contemporaneously administered as used herein u201c contemporaneously u201d means that they are administered such that the peak serum levels of the two medicaments occur within four hours of one another usually the closer to simultaneous peak serum levels the better compounds of formula i as described above were tested in the following assay for biological activity the wi 38 human lung fibroblast line was obtained from the atcc catalog number 75 ccl and maintained in basal medium eagle with earle 39 s salts gibcobrl product number 21010 046 supplemented with 2 mm glutamine and 10 fetal.