A: Transfer a quantity of Oral Solution,equivalent to about 15mg of oxycodone,to a separator,add 10mLof 0.01Nhydrochloric acid,and extract with four 40-mLportions of chloroform,collecting the chloroform extracts in a second separator.Wash the combined chloroform extracts with 5mLof 0.01Nhydrochloric acid,and discard the chloroform layer.Combine the acidic wash with the aqueous solution remaining in the first separator,and adjust with 6Nammonium hydroxide to a pHof 9.5±0.5.Extract with one 50-mLand two 20-mLportions of chloroform,and filter the chloroform extracts through chloroform-washed cotton,collecting the filtrate in a 100-mLvolumetric flask.Dilute with water-saturated chloroform to volume,and mix (test solution).Similarly prepare a Standard solution using about 12mg of USP Oxycodone RSand 25mLof 0.01Nhydrochloric acid,and proceed as directed above beginning with “extract with four 40-mLportions of chloroform.”The UVabsorption spectrum of the test solution exhibits maxima and minima at the same wavelengths as that of the Standard solution,concomitantly measured.

B: Separately evaporate 5mLof the test solution and 5mLof the Standard solution obtained in Identificationtest Ajust to dryness.Dissolve each residue in 1.0mLof chloroform.Apply separate 20-µLportions of the solution from the test solution and the solution from the Standard solution to a suitable thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture.Allow the spots to dry,and develop the chromatogram in solvent system consisting of a mixture of acetone,toluene,ether,and ammonium hydroxide (6:4:1:0.3)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chamber,mark the solvent front,allow the solvent to evaporate,and spray with iodoplatinate TS:the principal spot obtained from the solution from the test solution corresponds in color,size,and RFvalue to that obtained from the solution from the Standard solution,and no other spots are observed.

C: The retention time of the oxycodone peak in the chromatogram of the Assay preparationcorresponds to that in the chromatogram of the Standard preparationobtained as directed in the Assay.

Add the following:

FOR ORAL SOLUTION PACKAGED IN SINGLE-UNIT CONTAINERS: meets the requirements.USP28

Add the following:

FOR ORAL SOLUTION PACKAGED IN MULTIPLE-UNIT CONTAINERS: meets the requirements.USP28

Mobile phase,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Oxycodone Hydrochloride Tablets.

Assay preparation— Transfer an accurately measured volume of Oral Solution,equivalent to about 5mg of oxycodone hydrochloride,to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Pass a portion of this mixture through a filter having a 0.5-µm or finer porosity,and use the clear filtrate as the Assay preparation.

Procedure— Proceed as directed for Procedurein the Assayunder Oxycodone Hydrochloride Tablets.Calculate the quantity,in mg,of oxycodone hydrochloride (C18H21NO4·HCl)in each mLof the Oral Solution taken by the formula: in which Vis the volume,in mL,of Oral Solution taken;and the other terms are as defined therein.