Identification—
A:
Transfer a portion of Ophthalmic Ointment,equivalent to about 50mg of atropine sulfate,to a suitable separator,and dissolve in 25mLof ether.Add 25mLof 0.01Nhydrochloric acid,shake vigorously,allow the layers to separate,and discard the organic phase.Heat the aqueous phase gently on a steam bath while passing nitrogen through the solution,to expel any residual ether.Proceed as directed under
Identification—Organic Nitrogenous Bases á181ñ,beginning with “In a second separator dissolve 50mg.”
B:
Transfer about 5g of Ophthalmic Ointment to a separator,dissolve in 50mLof ether,and extract with 20mLof water:the extracted solution so obtained responds to the tests for Sulfate á191ñ.
Assay—
Proceed with Ophthalmic Ointment as directed in the
Assayunder
Atropine Sulfate Ophthalmic Solution,but in preparing the
Assay preparation,weigh accurately a portion of Ophthalmic Ointment,equivalent to about 10mg of atropine sulfate,transfer to a separator containing 50mLof ether,shake to dissolve,extract with three 25-mLportions of 0.1Msulfuric acid,collect the acid extracts in a 100-mLvolumetric flask,dilute with 0.1Msulfuric acid to volume,and mix.Proceed as directed for the
Assay preparationin the
Assayunder
Atropine Sulfate Ophthalmic Solution,beginning with “Pipet 10mLof this solution into a separator.”Calculate the quantity,in mg,of atropine sulfate [(C
17H
23NO
3)
2·H
2SO
4·H
2O]in the portion of Ophthalmic Ointment taken by the formula given therein.