Cyproheptadine Tablets

General Notices

Action and use

Histamine H1 receptor antagonist; antihistamine.

Definition

Cyproheptadine Tablets contain Cyproheptadine Hydrochloride.

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

Content of anhydrous cyproheptadine hydrochloride, C21H21N,HCl

90.0 to 110.0% of the stated amount.

Identification

A. To a quantity of the powdered tablets containing the equivalent of 20 mg of anhydrous cyproheptadine hydrochloride add 10 mL of water and 2.5 mL of 0.1m sodium hydroxide, extract with 10 mL of dichloromethane, filter through anhydrous sodium sulfate moistened with dichloromethane on absorbent cotton and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of cyproheptadine (RS 080).
B. In the test for Related substances, the principal spot in the chromatogram obtained with solution (3) corresponds to that in the chromatogram obtained with solution (5).
C. Extract a quantity of the powdered tablets containing the equivalent of 20 mg of anhydrous cyproheptadine hydrochloride with 7 mL of water, filter, add 0.3 mL of 5m ammonia to the filtrate and filter again. The filtrate yields reaction A characteristic of chlorides, Appendix VI.

Tests

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using a silica gel precoated plate (Merck silica gel 60 plates are suitable) and as the mobile phase a mixture of 10 volumes of methanol and 90 volumes of dichloromethane. Apply separately to the plate 10 µL of each of the following solutions. For solution (1) add a quantity of the powdered tablets containing the equivalent of 50 mg of anhydrous cyproheptadine hydrochloride to 5 mL of the mobile phase, shake mechanically for 10 minutes and filter (Whatman GF/C filter paper is suitable). Solution (2) contains 0.002% w/v of dibenzocycloheptene EPCRS in the mobile phase. For solution (3) dilute 1 volume of solution (1) to 10 volumes with the mobile phase. For solution (4) dilute 1 volume of solution (1) to 100 volumes with the mobile phase and dilute 1 volume to 10 volumes with the mobile phase. Solution (5) contains 0.1% w/v of cyproheptadine hydrochloride EPCRS in the mobile phase. Allow the plate to dry in air and spray with ethanolic sulfuric acid (20%). Heat at 110° for 30 minutes and examine under ultraviolet light (365 nm). In the chromatogram obtained with solution (1) any spot corresponding to dibenzocycloheptene is not more intense than the spot in the chromatogram obtained with solution (2) (0.2%) and any other secondary spot is not more intense than the spot in the chromatogram obtained with solution (4) (0.1%).

Assay

Weigh and powder 20 tablets. To a quantity of the powder containing the equivalent of 1.5 mg of anhydrous cyproheptadine hydrochloride add sufficient ethanol (96%) to produce 100 mL and filter if necessary. Measure the absorbance of the resulting solution at the maximum at 286 nm, Appendix II B. Calculate the content of C21H21N,HCl taking 355 as the value of A(1%, 1 cm) at the maximum at 286 nm.

Labelling

The quantity of active ingredient is stated in terms of the equivalent amount of anhydrous cyproheptadine hydrochloride.