Fluoxetine Capsules
Action and use
Selective serotonin reuptake inhibitor; antidepressant.
Definition
Fluoxetine Capsules contain Fluoxetine Hydrochloride.
Content of fluoxetine, C17H18F3NO
95.0 to 105.0% of the stated amount.
Identification
Tests
Dissolution
Comply with the requirements for Monographs of the British Pharmacopoeia in the dissolution test for tablets and capsules, Appendix XII B1. Prepare a mixture of 1 volume of diethylamine and 250 volumes of acetonitrile, mix well and adjust the pH to 3.5 with orthophosphoric acid (solution A); a white precipitate may form, keep the mixture well stirred.
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
2 volumes of diethylamine, 200 volumes of acetonitrile and 300 volumes of water, the mixture adjusted to pH 3.5 with orthophosphoric acid.
Calculate the content of C17H18F3NO in the medium from the chromatograms obtained using the declared content of C17H18F3NO,HCl in fluoxetine hydrochloride BPCRS and taking each mg of C17H18F3NO,HCl to be equivalent to 0.8944 mg of C17H18F3NO.
Related substances
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
If necessary, adjust the composition of the mobile phase so that, in the chromatogram obtained with solution (2), the retention time of the peak due to fluoxetine is between 10 and 20 minutes.
35 volumes of acetonitrile and 65 volumes of a solution containing 1 volume of triethylamine and 99 volumes of water, and adjusting the pH to 6.0 with orthophosphoric acid.
In the chromatogram obtained with solution (1):
the area of any secondary peak is not greater than half the area of the peak in the chromatogram obtained with solution (2) (0.25%);
the area of not more than two such peaks is greater than 0.2 times the area of the peak in the chromatogram obtained with solution (2) (0.1%);
and the sum of the areas of all the secondary peaks is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (0.5%).
Assay
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
33 volumes of a solution containing 0.3% w/v of glacial acetic acid and 0.64% w/v of sodium pentanesulfonate, adjusted to pH 5.0 with 5m sodium hydroxide, and 67 volumes of methanol.
Calculate the content of C17H18F3NO in the capsules from the chromatograms obtained using the declared content of C17H18F3NO,HCl in fluoxetine hydrochloride BPCRS and taking each mg of C17H18F3NO,HCl to be equivalent to 0.8944 mg of C17H18F3NO.
Labelling
The quantity of active ingredient is stated in terms of the equivalent amount of fluoxetine.
IMPURITIES
The impurities limited by the requirements of this monograph include impurities A and B listed under Fluoxetine Hydrochloride.