Pseudoephedrine Tablets

General Notices

Action and use

Adrenoceptor agonist.

Definition

Pseudoephedrine Tablets contain Pseudoephedrine Hydrochloride.

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

Content of pseudoephedrine hydrochloride, C₁₀H₁₅NO,HCl

95.0 to 105.0% of the stated amount.

Identification

A. Shake a quantity of the powdered tablets containing 60 mg of Pseudoephedrine Hydrochloride with 10 mL of water and filter. Shake the filtrate with 10 mL of ether, discard the ether, add 1 mL of 1m sodium hydroxide to the aqueous layer and extract with two 10 mL quantities of ether. Dry the combined ether extracts with anhydrous sodium sulfate, filter and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of pseudoephedrine (RS 304).

B. 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 a mixture of 10 volumes of 5m ammonia, 10 volumes of methanol, 20 volumes of acetone, 20 volumes of butan-1-ol and 40 volumes of butyl acetate as the mobile phase. Apply separately to the plate 10 µL of each of the following solutions. Remove any film coating from the tablets before proceeding. For solution (1) add 25 mL of methanol to a quantity of the powdered tablets containing 0.5 g of Pseudoephedrine Hydrochloride, shake for 5 minutes, filter, wash the filter with methanol and evaporate the combined filtrate and washings to dryness. Dissolve the residue as completely as possible in 5 mL of methanol, centrifuge and dilute 1 volume of the supernatant liquid to 10 volumes with methanol. Solution (2) contains 1.0% w/v of pseudoephedrine hydrochloride BPCRS in methanol. After removal of the plate, allow it to dry in a current of warm air, spray with a solution containing 0.3 g of ninhydrin in a mixture of 100 mL of butan-1-ol and 3 mL of glacial acetic acid and heat at 120° for 20 minutes. The principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).

Related substances

Carry out the method for liquid chromatography, Appendix III D, using the following solutions. Remove any film coating from the tablets before proceeding. For solution (1) add 25 mL of methanol to a quantity of the powdered tablets containing 0.5 g of Pseudoephedrine Hydrochloride, shake for 5 minutes, filter, wash the filter with methanol and evaporate the combined filtrate and washings to dryness. Dissolve the residue as completely as possible in 5 mL of methanol, centrifuge and dilute 1 mL of the supernatant liquid to 50 mL with the mobile phase. Solution (2) contains 0.002% w/v of ephedrine hydrochloride BPCRS in the mobile phase. Solution (3) contains 0.05% w/v of ephedrine hydrochloride BPCRS and 0.05% w/v of pseudoephedrine hydrochloride BPCRS in the mobile phase.

The chromatographic procedure may be carried out using (a) a stainless steel column (30 cm × 3.9 mm) packed with particles of silica the surface of which has been modified with chemically bonded phenyl groups (µBondapak Phenyl is suitable), (b) a mixture of 6 volumes of methanol and 94 volumes of 0.15m ammonium acetate, adjusted to pH 4.0 with glacial acetic acid, as the mobile phase with a flow rate of 1.0 mL per minute and (c) a detection wavelength of 257 nm.

The test is not valid unless, in the chromatogram obtained with solution (3), the resolution factor between the two principal peaks is at least 2.0.

In the chromatogram obtained with solution (1) the area of any peak corresponding to ephedrine is not greater than the area of the peak in the chromatogram obtained with solution (2) (1%).

Assay

Weigh and powder 20 tablets. Carry out the method for liquid chromatography, Appendix III D, using the following solutions. Solution (1) is a 0.12% w/v solution of pseudoephedrine hydrochloride BPCRS in methanol (50%). For solution (2) add 50 mL of 0.1m hydrochloric acid to a quantity of the powdered tablets containing 0.12 g of Pseudoephedrine Hydrochloride, mix with the aid of ultrasound for 15 minutes, add sufficient methanol to produce 100 mL, filter and use the filtrate.

The chromatographic procedure may be carried out using (a) a stainless steel column (20 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (10 µm) (Nucleosil C18 is suitable), (b) 0.005m dioctyl sodium sulfosuccinate in a mixture of 65 volumes of methanol, 35 volumes of water and 1 volume of glacial acetic acid as the mobile phase with a flow rate of 1.5 mL per minute and (c) a detection wavelength of 258 nm.

Calculate the content of C₁₀H₁₅NO,HCl using the declared content of C₁₀H₁₅NO,HCl in pseudoephedrine hydrochloride BPCRS.