Finasteride Tablets
Action and use
5-Alpha reductase inhibitor; treatment of benign prostatic hyperplasia.
Definition
Finasteride Tablets contain Finasteride. They are coated.
The tablets comply with the requirements stated under Tablets and with the following requirements.
Content of finasteride, C23H36N2O2
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.
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
21 volumes of water and 29 volumes of acetonitrile.
The test is not valid unless, in the chromatogram obtained with solution (2), the symmetry factor of the peak corresponding to finasteride is less than 2.0.
Calculate the content of C23H36N2O2 in the medium from the chromatograms obtained using the declared content of C23H36N2O2 in finasteride BPCRS.
Related substances
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
When the chromatograms are recorded using the prescribed conditions the retention time of finasteride is about 28 minutes. The retention times relative to finasteride are: impurity A, about 0.9; impurity B, about 1.2; impurity C, about 1.4. For solution (1) allow the chromatography to run for twice the retention time of the finasteride peak.
10 volumes of acetonitrile, 10 volumes of tetrahydrofuran and 80 volumes of water.
The test is not valid, unless in the chromatogram obtained with solution (3), the peak-to-valley ratio between finasteride impurity A and finasteride is at least 2.5.
In the chromatogram obtained with solution (1):
identify any peak due to finasteride impurity A and multiply the peak area by a correction factor of 2.4;
any peak corresponding to finasteride impurity A is not greater than 1.5 times the area of the principal peak in solution (2) (0.3%);
the area of any peak corresponding to finasteride impurity B is not greater than 1.5 times the area of the principal peak in solution (2) (0.3%);
the area of any peak corresponding to finasteride impurity C is not greater than 1.5 times the area of the principal peak in the chromatogram obtained with solution (2) (0.3%);
the area of any other secondary peak is not greater than 0.5 times the area of the principal peak in the chromatogram obtained with solution (2) (0.1%);
the sum of the areas of any secondary peaks is not greater than 3 times the area of the principal peak in the chromatogram obtained with solution (2) (0.6%).
Disregard any peak with an area less than 0.25 times the area of the peak due to finasteride in the chromatogram obtained with solution (2) (0.05%).
Uniformity of content
Tablets containing less than 2 mg and/or less than 2% w/w of Finasteride comply with the requirements stated under Tablets using the following method of analysis. Carry out the method for liquid chromatography, Appendix III D, using the following solutions in a mixture of 3 volumes of water and 7 volumes of acetonitrile (solvent A).
Equal volumes of acetonitrile and 0.0025m of orthophosphoric acid.
The test is not valid unless, in the chromatogram obtained with solution (2), the symmetry factor of the peak due to finasteride is less than 2.0.
Calculate the content of C23H36N2O2 in each tablet using the declared content of C23H36N2O2 in finasteride BPCRS.
Assay
For tablets containing less than 2 mg and/or less than 2% w/w of Finasteride
Use the average of the individual results determined in the test for Uniformity of content.
For tablets containing 2 mg or more and 2% w/w or more of Finasteride
Weigh and powder 20 tablets. Carry out the method for liquid chromatography, Appendix III D, using the following solutions in a mixture of 3 volumes of water and 7 volumes of acetonitrile (solvent A).
The chromatographic conditions described under Uniformity of content may be used.
The assay is not valid unless, in the chromatogram obtained with solution (2), the symmetry factor of the peak due to finasteride is less than 2.0.
Calculate the content of C23H36N2O2 in the tablets from the chromatograms obtained and using the declared content of C23H36N2O2 in finasteride BPCRS.
IMPURITIES
The impurities limited by the requirements of this monograph include those listed in the monograph for Finasteride.