Action and use
Histamine H2 receptor antagonist; treatment of peptic ulceration.
Definition
Cimetidine Tablets contain Cimetidine.
The tablets comply with the requirements stated under Tablets and with the following requirements.
Content of cimetidine, C10H16N6S
95.0 to 105.0% of the stated amount.
Identification
A. Shake a quantity of the powdered tablets containing 0.10 g of Cimetidine with 10 mL of
methanol for 10 minutes, filter (Whatman GF/A is suitable) and evaporate to dryness on a rotary evaporator using gentle heat. Dissolve the residue in 5 mL of
chloroform and evaporate to dryness with the aid of a current of air. Dry the residue at 60° at a pressure not exceeding 0.7 kPa. The
infrared absorption spectrum of the residue,
Appendix II A, is concordant with the
reference spectrum of cimetidine
(RS 061).
B. In the test for Related substances, the principal spot in the chromatogram obtained with solution (2) corresponds to that in the chromatogram obtained with solution (6).
TESTS
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
(1) Add 20 mL of
methanol to a quantity of the powdered tablets containing 1 g of Cimetidine, mix with the aid of ultrasound for 2 minutes, shake for 3 minutes and filter using a suitable 0.2-µm filter.
(2) Dilute 1 volume of solution (1) to 10 volumes with
methanol.
(3) Dilute 1 volume of solution (2) to 20 volumes with
methanol.
(4) Dilute 1 volume of solution (1) to 100 volumes with
methanol and dilute 20 volumes of this solution to 100 volumes with
methanol.
(5) Dilute 5 volumes of solution (4) to 10 volumes with
methanol.
Carry out the following tests.
A. chromatographic conditions
(b) Use the mobile phase as described below.
(c) Apply 4 µL of each solution.
(d) Develop the plate for 15 minutes in the tank saturated with vapour from the mobile phase.
(e) After removal of the plate, dry in a current of cold air, expose to iodine vapour until maximum contrast of the spots has been obtained and examine under
ultraviolet light (254 nm).
mobile phase
15 volumes of 13.5m ammonia, 20 volumes of methanol and 65 volumes of ethyl acetate.
B. chromatographic conditions
(b) Use the mobile phase as described below.
(c) Apply 4 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in a current of cold air, expose to iodine vapour until maximum contrast of the spots has been obtained and examine under
ultraviolet light (254 nm).
mobile phase
8 volumes of 13.5m ammonia, 8 volumes of methanol and 84 volumes of ethyl acetate.
system suitability
The tests are not valid unless the chromatograms obtained with solution (5) show clearly visible spots.
limits
Any secondary spot in the chromatogram obtained with solution (1) in tests A and B:
is not more intense than the principal spot in the chromatogram obtained with solution (3) (0.5%);
not more than two such spots are more intense than the principal spot in the chromatogram obtained with solution (4) (0.2% of each).
Assay
Weigh and finely powder 20 tablets. Shake a quantity of the powdered tablets containing 0.1 g of Cimetidine with 300 mL of 0.05m sulfuric acid for 20 minutes, add sufficient 0.05m sulfuric acid to produce 500 mL and filter (Whatman GF/C is suitable). Dilute 5 mL of the filtrate to 100 mL with 0.05m sulfuric acid (solution A). Prepare a 0.001% w/v solution of cimetidine BPCRS in 0.05m sulfuric acid (solution B). Measure the absorbance of solutions A and B at the maximum at 218 nm and at 260 nm, Appendix II B. Calculate the content of C10H16N6S using the difference between the absorbances of solutions A and B at the two wavelengths and the declared content of C10H16N6S in cimetidine BPCRS.