Imipramine Tablets
Action and use
Monoamine reuptake inhibitor; tricyclic antidepressant.
Definition
Imipramine Tablets contain Imipramine Hydrochloride. They are coated.
Content of imipramine hydrochloride, C19H24N2,HCl
92.5 to 107.5% of the stated amount.
Identification
Triturate a quantity of the powdered tablets containing 0.25 g of Imipramine Hydrochloride with 10 mL of chloroform, filter, evaporate the filtrate to low volume, add ether until a turbidity is produced and allow to stand. The precipitate complies with the following tests.
Tests
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using silica gel G as the coating substance and a mixture of 5 volumes of hydrochloric acid, 5 volumes of water, 35 volumes of glacial acetic acid and 55 volumes of ethyl acetate as the mobile phase but allowing the solvent front to ascend 12 cm above the line of application. Apply separately to the plate 10 µL of each of the following solutions prepared immediately before use. For solution (1) shake a quantity of the powdered tablets containing 0.20 g of Imipramine Hydrochloride with three 10 mL quantities of chloroform, filter the combined chloroform extracts, evaporate to dryness and dissolve the residue in 10 mL of methanol. For solution (2) dilute 3 volumes of solution (1) to 100 volumes with methanol and dilute 1 volume of the resulting solution to 10 volumes with methanol. Solution (3) contains 0.0060% w/v of iminodibenzyl in methanol. After removal of the plate, allow it to dry for 5 minutes, spray with a 0.5% w/v solution of potassium dichromate in sulfuric acid (20%) and examine immediately. In the chromatogram obtained with solution (1) any spot corresponding to iminodibenzyl is not more intense than the spot in the chromatogram obtained with solution (3) (0.3%) and any other secondary spot is not more intense than the spot in the chromatogram obtained with solution (2) (0.3%).
Assay
Powder 10 tablets and transfer quantitatively without loss into 300 mL of 0.1m hydrochloric acid. Shake for 30 minutes, add sufficient 0.1m hydrochloric acid to produce 500 mL and filter through a fine glass microfibre filter (GF/C paper is suitable). Dilute a suitable volume of the filtrate with 0.1m hydrochloric acid to produce a solution containing 0.0025% w/v of Imipramine Hydrochloride and measure the absorbance of the resulting solution at the maximum at 250 nm, Appendix II B. Calculate the content of C19H24N2,HCl taking 264 as the value of A (1%, 1 cm) at the maximum at 250 nm.