Moxisylyte Tablets

General Notices

Action and use

Alpha-adrenoceptor antagonist.

Definition

Moxisylyte Tablets contain Moxisylyte Hydrochloride.

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

Content of moxisylyte, C16H25NO3

92.5 to 107.5% of the stated amount.

Identification

Shake a quantity of the powdered tablets containing the equivalent of 20 mg of moxisylyte with 10 mL of chloroform, filter and evaporate the filtrate to dryness. The residue complies with the following tests.

A. The infrared absorption spectrum, Appendix II A, is concordant with the reference spectrum of moxisylyte hydrochloride (RS 238).
B. Dilute 20 mL of a 0.03% w/v solution to 100 mL with water (solution A). Dilute a further 20 mL of the same solution to 100 mL with 0.1m sodium hydroxide (solution B). The ratio of the absorbance of solution B at 302 nm, measured 30 minutes after preparation, to that of solution A at 275 nm is about 1.7, Appendix II B.

Related substances

Carry out the method for liquid chromatography, Appendix III D, using the following solutions.

(1) Shake a quantity of the powdered tablets containing the equivalent of 0.18 g of moxisylyte with 100 mL of the mobile phase for 15 minutes, centrifuge and use the clear supernatant liquid.
(2) 0.0040% w/v of 2-(6-hydroxythymoxy)ethyldimethylamine hydrochloride BPCRS and 0.00050% w/v of 2-thymoxyethyldimethylamine hydrochloride BPCRS in the mobile phase.
(3) Dilute 1 volume of solution (1) to 100 volumes with the mobile phase.
(4) Dilute 1 volume of solution (3) to 10 volumes with the mobile phase.
chromatographic conditions
(a) Use a stainless steel column (30 cm x 3.9 mm) packed with octadecylsilyl silica gel for chromatography (10 µm) (µBondapak C18 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1.0 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 276 nm.
(f) Inject 20 µL of each solution.
mobile phase

0.005M sodium hexanesulfonate in a mixture of 2 volumes of glacial acetic acid, 185 volumes of water and 315 volumes of methanol.

The peaks in the chromatogram obtained with solution (2) are due to: (a) 2-(6-hydroxythymoxy)ethyldimethylamine hydrochloride and (b) 2-thymoxyethyldimethylamine hydrochloride in order of their elution.

limits

In the chromatogram obtained with solution (1):

the area of any peak corresponding to 2-(6-hydroxythymoxy)ethyldimethylamine hydrochloride is not greater than the area of the corresponding peak in the chromatogram obtained with solution (2) (2%);

the area of any peak corresponding to 2-thymoxyethyldimethylamine hydrochloride is not greater than the area of the corresponding peak in the chromatogram obtained with solution (2) (0.25%);

the area of any peak with a retention time relative to moxisylyte of 2.3 (2-(6-chlorothymoxy)ethyldimethylamine hydrochloride) is not greater than the area of the principal peak in the chromatogram obtained with solution (3) (1%);

the area of any peak with a retention time relative to moxisylyte of 0.9 (2-(6-acetylthymoxy)ethyldimethylamine) is not greater than the area of the principal peak in the chromatogram obtained with solution (4) (0.1%).

Assay

Weigh and powder 20 tablets. Shake a quantity of the powder containing the equivalent of 13 mg of moxisylyte with 150 mL of 0.1m hydrochloric acid, add sufficient 0.1m hydrochloric acid to produce 250 mL and filter. Measure the absorbance of the filtrate at the maximum at 275 nm, Appendix II B. Calculate the content of C16H25NO3 in the tablets taking 79.7 as the value of A (1%, 1 cm) at the maximum at 275 nm.

Storage

Moxisylyte Tablets should be protected from light.

Labelling

The quantity of active ingredient is stated in terms of the equivalent amount of moxisylyte.

40 mg of moxisylyte is equivalent to 45.2 mg of Moxisylyte Hydrochloride.