A: Infrared Absorption 197K.

B: A solution meets the requirements of the tests for Chloride 191.

Mobile phase— Proceed as directed in the Assay.

Test solution 1— Transfer about 56 mg of Fluoxetine Hydrochloride, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.

Test solution 2— Transfer 2 mL of Test solution 1, accurately measured, to a 10-mL volumetric flask, dilute with Mobile phase to volume, and mix.

System suitability solution— Dissolve about 22 mg of USP Fluoxetine Hydrochloride RS in 10 mL of 1 N sulfuric acid, and heat to 85 for 3 hours. Cool, transfer 0.4 mL of this solution to a 25-mL volumetric flask, and add about 28 mg of USP Fluoxetine Hydrochloride RS, 1 mg of USP Fluoxetine Related Compound A RS, and 1 mg of USP Fluoxetine Related Compound B RS. Dilute with Mobile phase to volume, and mix.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 215-nm detector and a 4.6-mm × 25-cm column that contains 5-µm base-deactivated packing L7. The flow rate is about 1 mL per minute. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.24 for -[2-(methylamino)ethyl]benzenemethanol (if present), 0.27 for fluoxetine related compound B (if present), 0.94 for fluoxetine related compound A, 1.0 for fluoxetine, and 2.17 for 4-trifluoromethylphenol; and the ratio of the height of the fluoxetine related compound A peak to the depth of the valley between the fluoxetine and fluoxetine related compound A peaks (measured from the fluoxetine related compound A peak height) is not more than 1.1.

Procedure— Separately inject equal volumes (about 10 µL) of Test solution 1 and Test solution 2 into the chromatograph, record the chromatograms for not less than twice the elution time for fluoxetine, and measure the peak responses. Calculate the percentage of fluoxetine related compound A in the portion of Fluoxetine Hydrochloride taken by the formula: in which rA is the peak response of fluoxetine related compound A obtained from Test solution 2; and rU is the peak response of fluoxetine obtained from Test solution 2.

(Official January 1, 2007)

Triethylamine buffer— Transfer about 10 mL of triethylamine, accurately measured, to a suitable container, add about 980 mL of water, and adjust with phosphoric acid to a pH of 6.0.

Mobile phase— Prepare a filtered and degassed mixture of Triethylamine buffer, stabilizer-free tetrahydrofuran, and methanol (6:3:1). Make adjustments if necessary (see System Suitability under Chromatography 621).

Standard preparation— Dissolve an accurately weighed quantity of USP Fluoxetine Hydrochloride RS in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 0.11 mg per mL.

Assay preparation— Transfer about 11 mg of Fluoxetine Hydrochloride, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with Mobile phase to volume, and mix.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 227-nm detector and a 4.6-mm × 25-cm column that contains 5-µm base-deactivated packing L7. The flow rate is about 1 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the tailing factor is not more than 2.0, and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C17H18 F3NO·HCl in the portion of Fluoxetine Hydrochloride taken by the formula: in which C is the concentration, in mg per mL, of USP Fluoxetine Hydrochloride RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.