Packaging and storage— Preserve in tight containers (inhalers),and avoid exposure to excessive heat.

Identification— Place the contents of 1inhaler in a glass-stoppered flask,add 50mLof methanol,and allow to stand for 1hour with frequent agitation.Filter,pressing out the roll on the filter.Add to the filtrate 1Nhydrochloric acid until it is slightly acid to moistened litmus paper,then add 30mLof water,and evaporate to about 20mL.Cool,transfer to a small separator,and shake with 10mLof ether.Withdraw the water layer,warm it on a steam bath to expel any ether,and dilute to about 25mL.From 10mLof the solution,precipitate the propylhexedrine with trinitrophenol TSas directed in Identificationtest Aunder Propylhexedrine:the propylhexedrine picrate so obtained melts between 108and 110(see Melting Range or Temperature á741ñ).[Caution—Picrates may explode. ]

Assay— Place the contents of 2inhalers of Inhalant in the thimble of a continuous-extraction apparatus,and quickly assemble the apparatus.Rinse each of the emptied inhalers with about 20mLof methanol,pouring the rinsings through the condenser into the extraction flask.Add through the condenser 20mLto 30mLof methanol,and extract for 15to 20cycles.Cool the extract,transfer it completely with the aid of small portions of methanol to a 100-mLvolumetric flask,dilute with methanol to volume,and mix.To 50.0mLof the solution add 25.0mLof 0.1Nsulfuric acid VS,and evaporate to about 40mL.Cool,add methyl red TS,and titrate the excess acid with 0.1Nsodium hydroxide VS.Each mLof 0.1Nsulfuric acid is equivalent to 15.53mg of C10H21N.

Expert Committee:(AER)Aerosols

USP28–NF23Page 1665

Phone Number:1-301-816-8269