A: Place a quantity of finely powdered Tablets, equivalent to about 50 mg of anileridine, in a 250-mL volumetric flask, add 100 mL of water, and heat on a steam bath. Cool, dilute with water to volume, mix, and filter: five mL of the filtrate responds to Identification test C under Anileridine Hydrochloride.

B: Transfer to a 100-mL volumetric flask a quantity of finely powdered Tablets, equivalent to about 50 mg of anileridine. Add about 30 mL of water, and heat on a steam bath. Cool, dilute with water to volume, mix, and filter (Stock solution): the filtrate responds to Identification test B under Anileridine Hydrochloride, beginning with “Transfer 4.0 mL of this solution.”

Medium: 0.01 N hydrochloric acid; 900 mL.

Apparatus 1: 100 rpm.

Time: 45 minutes.

Procedure— Determine the amount of anileridine (C22H28N2O2) dissolved, employing the procedure set forth in the Assay, using a filtered portion of the solution under test as the Assay preparation in comparison with a Standard solution having a known concentration of USP Anileridine Hydrochloride RS in the same Medium.

Tolerances— Not less than 65% (Q) of the labeled amount of C22H28N2O2 is dissolved in 45 minutes.

(Official January 1, 2007)

Standard preparation— Prepare as directed in the Assay under Anileridine Injection.

Assay preparation— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 50 mg of anileridine, to a 250-mL volumetric flask. Add 25 mL of 1 N hydrochloric acid and 100 mL of water, and heat on a water bath. Cool, dilute with water to volume, and mix. Filter the solution, discarding the first 25 mL of the filtrate.

Procedure— Proceed as directed for Procedure in the Assay under Anileridine Injection. Calculate the quantity, in mg, of C22H28N2O2 in the portion of Tablets taken by the formula: in which 352.48 and 425.40 are the molecular weights of anileridine and anileridine hydrochloride, respectively; C is the concentration, in µg per mL, of USP Anileridine Hydrochloride RS in the Standard preparation; and AU and AS are the absorbances of the solutions from the Assay preparation and the Standard preparation, respectively.