摘要 |
1,1,1,2,3,3,3-heptafluoropropane (HFC-227) has been identified as a highly polar propellant. Surfactants which have an elevated value (9.6 or greater) for their hydrophilic-lipophilic balance (HLB) can be used as suspending, wetting, and lubricating agents or cosolvents in metered dose inhaler (MDI) formulations pressurized with HFC-227 or propellant blends that contain HFC-227. Particularly, preferred surfactants include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan mono-oleate, polyethylene glycol 300, propoxylated polyethylene glycol, polyoxyethylene 4 lauryl ether, and diethylene glycol monoethyl ether.
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