Bromocriptine Tablets

General Notices

Action and use

Dopamine receptor agonist.

Definition

Bromocriptine Tablets contain Bromocriptine Mesilate.

The tablets comply with the requirements stated under Tablets 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 powdered tablets 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 chromatogram obtained with solution (1) shows a peak with the same retention time as the principal peak in the chromatogram obtained with solution (2).

Tests

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.

(1) Shake a quantity of the powdered tablets containing the equivalent of 10 mg of bromocriptine with 25 mL of a mixture of equal volumes of chloroform and methanol for 30 minutes, filter through a sintered-glass filter (ISO 4793, porosity grade 4, is suitable) and wash the residue with two 5-mL quantities of the solvent mixture. Evaporate the filtrate and washings to dryness at 25° at a pressure of 2 kPa, dissolve the residue in 2 mL of the solvent mixture and centrifuge.
(2) Dilute 1 volume of solution (1) to 10 volumes with a mixture of equal volumes of chloroform and methanol.
(3) Dilute 3 volumes of solution (2) to 10 volumes with a mixture of equal volumes of chloroform and methanol.
(4) Dilute 1 volume of solution (2) to 10 volumes with a mixture of equal volumes of chloroform and methanol.
(5) Dilute 1 volume of solution (2) to 20 volumes with a mixture of equal volumes of chloroform and methanol.
(6) 0.055% w/v of bromocriptine mesilate BPCRS in a mixture of equal volumes of chloroform and methanol.
chromatographic conditions
(a) Use as the coating silica gel G.
(b) Use the mobile phase as described below.
(c) Apply 20 µL of each solution as 10-mm bands.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in 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.

Uniformity of content

Tablets containing less than the equivalent of 2 mg and/or less than 2% w/w of bromocriptine comply with the requirements stated under Tablets using the following method of analysis. Mix one tablet with 50 mL of ethanol (50%) with the aid of ultrasound until disintegrated, shake for 30 minutes and centrifuge. Measure the absorbance of the supernatant liquid at the maximum at 305 nm, Appendix II B. Calculate the content of C32H40BrN5O5 taking 144 as the value of A(1%, 1 cm) at the maximum at 305 nm.

Assay

Prepare the solutions in subdued light. Weigh and powder 20 tablets. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.

(1) Mix a quantity of the powdered tablets containing the equivalent of 10 mg of bromocriptine with 70 mL of methanol (50%) with the aid of ultrasound for 5 minutes, shake for 30 minutes, filter and dilute to 100 mL with the same solvent.
(2) 0.011% w/v of bromocriptine mesilate BPCRS in methanol (50%).
(3) Heat a 0.011% w/v solution of bromocriptine mesilate BPCRS in a mixture of 1 volume of 1m acetic acid and 9 volumes of methanol at 60° for 90 minutes and cool to room temperature.
chromatographic conditions
(a) Use a stainless steel column (10 cm × 4 mm) packed with octadecylsilyl silica gel for chromatography (5 µm) (Spherisorb ODS 1 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1 mL per minute.
(d) Use an 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 in the tablets using the declared content of C32H40BrN5O5 in bromocriptine mesilate BPCRS.

Storage

Bromocriptine Tablets 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.