Fluoxetine Oral Solution
» Fluoxetine Oral Solution contains an amount of Fluoxetine Hydrochloride equivalent to not less than 90.0 percent and not more than 110.0 percent of the labeled amount of fluoxetine (C17H18F3NO). It may contain one or more preservatives.
Packaging and storage
Preserve in tight, light-resistant containers.
Identification, Infrared Absorption 197S
Solution
Transfer a volume of Oral Solution, equivalent to about 20 mg of fluoxetine, to a separatory funnel, add 5.0 mL of water and 0.5 mL of 1 N sodium hydroxide, extract with 5 mL of chloroform, and discard the aqueous layer. Evaporate the remaining layer to dryness, and dissolve the residue in 0.4 mL of chloroform.
Uniformity of dosage units 905
for oral solution packaged in single-unit containers:
meets the requirements.
Deliverable volume 698
for oral solution packaged in multiple-unit containers:
meets the requirements.
pH 791:
between 2.5 and 4.5.
Chromatographic purity
Ion-pair solution
Transfer about 4.3 g of sodium 1-octanesulfonate and 13.8 g of monobasic sodium phosphate to a suitable container, dissolve in 1 L of water, and adjust with phosphoric acid to a pH of 3.0.
Diluent
Prepare a mixture of Ion-pair solution, methanol, and acetonitrile (6:3:1).
Solution A
Prepare a filtered and degassed mixture of Ion-pair solution, methanol, and acetonitrile (53:26:21).
Solution B
Prepare a filtered and degassed mixture of Ion-pair solution, acetonitrile, and methanol (43:35:22).
Mobile phase
Use variable mixtures of Solution A and Solution B as directed for Chromatographic system. Make adjustments if necessary (see System Suitability under Chromatography 621).
System suitability solution
Dissolve a quantity of USP Fluoxetine Hydrochloride RS in 1 N sulfuric acid to obtain a solution having a known concentration of about 2.0 mg per mL, and heat at 85 for 1 hour. Transfer 1.0 mL of this solution to a 100-mL volumetric flask, add about 10 mg of USP Fluoxetine Hydrochloride RS, dissolve in and dilute with Diluent to volume, and mix.
Test solution
Transfer an accurately measured volume of Oral Solution, equivalent to about 19 mg of fluoxetine, to a 10-mL volumetric flask, dilute with Diluent to volume, and mix.
Diluted test solution
Transfer 1.0 mL of the Test solution to a 25-mL volumetric flask, dilute with Diluent 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 packing L1. The flow rate is about 1 mL per minute. The chromatograph is programmed as follows.
Procedure
Separately inject equal volumes (about 20 µL) of the Diluted test solution and the Test solution into the chromatograph, record the chromatograms, and measure all of the peak responses. Calculate the percentage of each impurity in the volume of Oral Solution taken by the formula:
100ri / (Sri + 25rS)
in which ri is the peak response for each impurity obtained from the Test solution; and rS is the peak response for fluoxetine obtained from the Diluted test solution: not more than 0.4% of any individual impurity is found; and not more than 0.8% of total impurities is found.
Assay
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 and acetonitrile (1:1). 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 45 µg per mL.
Assay preparation
Transfer an accurately measured volume of Oral Solution, equivalent to about 4.0 mg of fluoxetine, to a 100-mL volumetric flask, 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 packing L10. 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 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the fluoxetine peak. Calculate the quantity, in mg, of fluoxetine (C17H18F3NO) in the volume of Oral Solution taken by the formula:
(309.33/345.79)(0.1C)(rU / rS)
in which 309.33 and 345.79 are the molecular weights for fluoxetine and fluoxetine hydrochloride, respectively; C is the concentration, in µg 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.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
Chromatographic Column
USP32NF27 Page 2417
Pharmacopeial Forum: Volume No. 29(6) Page 1886
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.
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