Action and use
Dopamine receptor agonist.
Definition
Bromocriptine Capsules contain Bromocriptine Mesilate.
The capsules comply with the requirements stated under Capsules and with the following requirements.
Content of bromocriptine, C32H40BrN5O5
90.0 to 110.0% of the stated amount.
Identification
A. Shake a quantity of the contents of the capsules containing the equivalent of 10 mg of bromocriptine with 50 mL of
methanol for 30 minutes, centrifuge and dilute 5 mL of the supernatant liquid to 20 mL with
methanol. The
light absorption of the resulting solution,
Appendix II B, in the range 230 to 380 nm exhibits a maximum at 305 nm and a minimum at 270 nm.
B. In the test for Related substances, the principal band in the chromatogram obtained with solution (2) corresponds to that in the chromatogram obtained with solution (6).
C. In the Assay, the retention time of the principal peak in the chromatogram obtained with solution (1) is the same as that of the principal peak in the chromatogram obtained with solution (2).
Test
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions, prepare the solutions in subdued light and immediately before use. Apply solution (1) as the last solution and develop the chromatograms immediately in an unsaturated tank.
(1) Shake a quantity of the contents of the capsules containing the equivalent of 20 mg of bromocriptine with 10 mL of
methanol for 20 minutes and centrifuge.
(2) Dilute 1 volume of solution (1) to 10 volumes with
methanol.
(3) Dilute 3 volumes of solution (1) to 100 volumes with
methanol.
(4) Dilute 1 volume of solution (1) to 100 volumes with
methanol.
(5) Dilute 1 volume of solution (1) to 200 volumes with
methanol.
chromatographic conditions
(b) Use the mobile phase as described below.
(c) Apply 50 µL of each solution as 10-mm bands.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry it in a current of cold air for 2 minutes, spray with
ammonium molybdate solution R3 and heat at 100° until bands appear (about 10 minutes).
mobile phase
0.1 volumes of 13.5m ammonia, 1.5 volumes of water, 3 volumes of propan-2-ol, 88 volumes of dichloromethane and 100 volumes of ether.
limits
In the chromatogram obtained with solution (1):
any secondary band is not more intense than the band in the chromatogram obtained with solution (3) (3%);
not more than one such band is more intense than the band in the chromatogram obtained with solution (4) (1%);
not more than a further two such bands are more intense than the band in the chromatogram obtained with solution (5) (0.5%).
Disregard any band within 20 mm of the line of application.
Assay
Prepare the solutions in subdued light. Weigh and powder the contents of 20 capsules. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
(1) Mix a quantity of the capsule contents containing the equivalent of 10 mg of bromocriptine with 70 mL of
methanol (50%) with the aid of ultrasound for 5 minutes, filter and dilute to 100 mL with the same solvent.
chromatographic conditions
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1 mL per minute.
(d) Use ambient column temperature.
(e) Use a detection wavelength of 300 nm.
(f) Inject 20 µL of each solution.
mobile phase
45 volumes of a 0.08% w/v solution of ammonium carbonate and 55 volumes of acetonitrile.
system suitability
The assay is not valid unless the resolution factor between the two peaks obtained with solution (3) is not less than 3.0.
determination of content
Calculate the content of C32H40BrN5O5 using the declared content of C32H40BrN5O5 in bromocriptine mesilate BPCRS.
Storage
Bromocriptine Capsules should be kept in an airtight container and protected from light.
Labelling
The quantity of active ingredient is stated in terms of the equivalent amount of bromocriptine.