Mepyramine Tablets

General Notices

Action and use

Histamine H1 receptor antagonist; antihistamine.

Definition

Mepyramine Tablets contain Mepyramine Maleate.

The tablets comply with the requirements stated under Tablets and with the following requirements.

Content of mepyramine maleate, C17H23N3O,C4H4O4

95.0 to 105.0% of the stated amount.

Identification

A. Shake a quantity of the powdered tablets containing 0.1 g of Mepyramine Maleate with 10 mL of dichloromethane, filter and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of mepyramine maleate (RS 216).
B. In the test for Related substances, the principal spot in the chromatogram obtained with solution (2) is similar in position and size to that in the chromatogram obtained with solution (4).
C. Dissolve a quantity of the powdered tablets containing 0.2 g of Mepyramine Maleate, freed as far as possible from any sugar coating, in 3 mL of water, add 2 mL of 5m sodium hydroxide and shake with three 3-mL quantities of ether. Warm the aqueous layer in a water bath for 10 minutes with 2 mL of bromine solution, heat to boiling, cool and add 0.2 mL to a solution of 10 mg of resorcinol in 3 mL of sulfuric acid. A bluish-black colour is produced on heating for 15 minutes in a water bath.

TESTS

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions in chloroform. Prepare the solutions immediately before use.

(1) Shake a quantity of the powdered tablets containing 0.4 g of Mepyramine Maleate with 10 mL of chloroform and filter.
(2) Dilute 1 volume of solution (1) to 10 volumes.
(3) 4% w/v of mepyramine maleate EPCRS.
(4) 0.4% w/v of mepyramine maleate EPCRS.
(5) 0.008% w/v of mepyramine maleate EPCRS.
(6) 0.004% w/v of mepyramine maleate EPCRS.
chromatographic conditions
(a) Use as the coating silica gel F254.
(b) Use the mobile phase as described below.
(c) Apply 5 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm).
mobile phase

2 volumes of diethylamine and 100 volumes of ethyl acetate.

system suitability

The test is not valid unless the Rf values of the principal spots in the chromatograms obtained with solutions (1) and (3) are at least 0.2 and unless the spot in the chromatogram obtained with solution (6) is clearly visible.

limits

Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (5) (0.2%). Disregard the spot due to maleic acid on the line of application.

Assay

Weigh and powder 20 tablets. To a quantity of the powder containing 0.1 g of Mepyramine Maleate add 75 mL of water and 5 mL of 2m hydrochloric acid, shake vigorously for 15 minutes and dilute to 100 mL with water. Centrifuge and dilute 10 mL of the clear, supernatant liquid to 100 mL with water. To 10 mL of the resulting solution add 10 mL of 0.1m hydrochloric acid and dilute to 100 mL with water. Measure the absorbance of the resulting solution at the maximum at 316 nm, Appendix II B. Calculate the content of C17H23N3O,C4H4O4 in the tablets taking 206 as the value of A(1%, 1 cm) at the maximum at 316 nm.