Cyclizine Tablets

Histamine H₁ receptor antagonist; antihistamine.

Cyclizine Tablets contain Cyclizine Hydrochloride.

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

92.5 to 107.5% of the stated amount.

A. Extract a quantity of the powdered tablets containing 0.1 g of Cyclizine Hydrochloride with 10 mL of ethanol (96%), filter and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of Cyclizine Hydrochloride (RS 076).

B. Extract a quantity of the powdered tablets containing 0.5 g of Cyclizine Hydrochloride with 20 mL of water and filter. The filtrate yields reaction A characteristic of chlorides, Appendix VI.

Carry out the method for thin-layer chromatography, Appendix III A, using silica gel G as the coating substance and as the mobile phase the lower layer obtained after shaking together a mixture of 2 volumes of 13.5m ammonia, 8 volumes of methanol and 90 volumes of dichloromethane and allowing the layers to separate. Apply separately to the plate 20 µL of each of the following freshly prepared solutions. For solution (1) triturate a quantity of the powdered tablets containing 0.10 g of Cyclizine Hydrochloride with 10 mL of methanol and filter. For solution (2) dilute 1 volume of solution (1) to 200 volumes with methanol. Solution (3) contains 0.0050% w/v of N-methylpiperazine in methanol. For solution (4) dilute 1 volume of solution (1) to 10 volumes with a 0.10% w/v solution of hydroxyzine hydrochloride BPCRS in methanol. After removal of the plate, allow it to dry in air and expose to iodine vapour for 10 minutes. Any spot corresponding to N-methylpiperazine in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (3) (0.5%). Any other secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.5%). The test is not valid unless the chromatogram obtained with solution (4) shows two clearly separated spots.

Weigh and powder 20 tablets. Shake a quantity of the powder containing 0.125 g of Cyclizine Hydrochloride with 400 mL of 0.05m sulfuric acid for 15 minutes. Add sufficient 0.05m sulfuric acid to produce 500 mL, filter, dilute 5 mL of the filtrate to 100 mL with 0.05m sulfuric acid and measure the absorbance of the resulting solution at the maximum at 225 nm, Appendix II B. Calculate the content of C₁₈H₂₂N₂,HCl taking 390 as the value of A(1%, 1 cm) at the maximum at 225 nm.