microns preferably less than 10 microns for example from 1 to 10 microns 1 to 5 microns or from 2 to 5 microns where appropriate small amounts of other anti asthmatics and bronchodilators for example sympathomimetic amines such as isoprenaline isoetharine salbutamol phenylephrine and ephedrine corticosteroids such as prednisolone and adrenal stimulants such as acth may be included for parenteral administration fluid unit dosage forms are prepared utilizing the compound and a sterile vehicle and depending on the concentration used can be either suspended or dissolved in the vehicle in preparing solutions the compound can be dissolved in water for injection and filter sterilised before filling into a suitable vial or ampoule and sealing advantageously adjuvants such as local anaesthetic a preservative and buffering agents can be dissolved in the vehicle to enhance the stability the composition can be frozen after filling into the vial and the water removed under vacuum parenteral suspensions are prepared in substantially the same manner except that the compound is suspended in the vehicle instead of being dissolved and sterilisation cannot be accomplished by filtration the compound can be sterilised by exposure to ethylene oxide before suspending in the sterile vehicle advantageously a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the compound the compositions may contain from 0 1 to 99 by weight preferably from 10 60 by weight of the active material depending on the method of administration compounds of formula i or if appropriate a pharmaceutically acceptable salt thereof and or a pharmaceutically acceptable solvate thereof may.