Apomorphine Hydrochloride Tablets
»Apomorphine Hydrochloride Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amount of C17H17NO2·HCl·½H2O.
Packaging and storage— Preserve in tight,light-resistant containers.
Color of solution— Dissolve a quantity of powdered Tablets,equivalent to 5mg of apomorphine hydrochloride,in water to make 100.0mL.Transfer 1.0mLof the solution to a test tube,dilute with 6mLof water,and,if necessary,filter through a small pledget of cotton.Add 1mLof sodium bicarbonate solution (1in 20),then add 0.50mLof iodine TS.Allow to stand for 30seconds,then add 0.60mLof sodium thiosulfate solution (1in 40),and dilute with water to 10mL.This solution represents the color standard.
Place a quantity of powdered Tablets,equivalent to about 50mg of apomorphine hydrochloride,in a test tube of suitably small size,add 10.0mLof cold,oxygen-free water,insert the stopper in the test tube,and agitate gently until no more dissolves;if necessary,filter immediately through a small pledget of cotton.The color of the solution,observed promptly after preparation,is not more intense than that of the color standard.Use closely matched test tubes for the comparison.
Identification— To 5mLof a filtered solution of Tablets,containing about 10mg of apomorphine hydrochloride,add a slight excess of sodium bicarbonate solution (1in 20):a white or greenish-white precipitate is formed.Add 3drops of iodine TS,and shake vigorously:an emerald-green color is produced.Add 5mLof ether,and,after vigorous shaking,allow the layers to separate:the ether is colored deep ruby-red while the water layer retains its green color.
Uniformity of dosage units á905ñ: meet the requirements.
Procedure for content uniformity— Place 1Tablet in a 500-mLvolumetric flask containing 100mLof 0.1Nhydrochloric acid,and shake for 15minutes.Dilute with 0.1Nhydrochloric acid to volume,mix,and filter,discarding the first 20mLof filtrate.Dilute a portion of the subsequent filtrate quantitatively and stepwise,if necessary,with 0.1Nhydrochloric acid to provide a solution containing approximately 12µg of apomorphine hydrochloride per mL.Concomitantly determine the absorbances of this solution and of a solution of USP Apomorphine Hydrochloride RSin the same medium having a known concentration of about 12µg of anhydrous apomorphine hydrochloride per mL,in 1-cm cells at the wavelength of maximum absorbance at about 273nm,with a suitable spectrophotometer,using 0.1Nhydrochloric acid as the blank.Calculate the quantity,in mg,of C17H17NO2·HCl·½H2Oin the Tablet taken by the formula:
(312.80/303.79)(TC/D)(AU/AS),
in which 312.80and 303.79are the molecular weights of apomorphine hydrochloride hemihydrate and anhydrous apomorphine hydrochloride,respectively;Tis the labeled quantity,in mg,of apomorphine hydrochloride in the Tablet;Cis the concentration,in µg per mL,of anhydrous apomorphine hydrochloride in the Standard solution;Dis the concentration,in µg per mL,of apomorphine hydrochloride in the solution from the Tablet,based upon the labeled quantity per Tablet and the extent of dilution;and AUand ASare the absorbances of the solution from the Tablet and the Standard solution,respectively.
Assay— Weigh and finely powder not fewer than 20Tablets.Dissolve an accurately weighed portion of the powder,equivalent to about 50mg of apomorphine hydrochloride,in 25mLof water in a separator,add 500mg of sodium bicarbonate,and completely extract with successive small portions of ether.Combine the ether extracts in a separator,and wash them with three 5-mLportions of water.Shake the combined water washings with 10mLof ether,and add this ether to the combined ether extracts.Extract the ether solutions with 20.0mLof 0.02Nsulfuric acid VS,and wash with three 5-mLportions of water.Combine the acid extract and washings in a beaker,and warm on a steam bath to expel any residual ether.Cool,add methyl red TS,and titrate the excess acid with 0.02Nsodium hydroxide VS(see Residual Titrationsunder Titrimetry á541ñ).Each mLof 0.02Nsulfuric acid is equivalent to 6.256mg of C17H17NO2·HCl·½H2O.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 174
Phone Number:1-301-816-8251