Cyclopenthiazide Tablets

General Notices

Action and use

Thiazide-like diuretic.

Definition

Cyclopenthiazide Tablets contain Cyclopenthiazide.

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

Content of cyclopenthiazide, C13H18ClN3O4S2

90.0 to 110.0% of the stated amount.

Identification

Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.

(1) Shake a quantity of the powdered tablets containing 5 mg of Cyclopenthiazide with 5 mL of acetone and filter.
(2) 0.1% w/v of cyclopenthiazide BPCRS in acetone.
chromatographic conditions
(a) Use as the coating silica gel GF254.
(b) Use the mobile phase as described below.
(c) Apply 5 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in air, examine under ultraviolet light (254 nm) and then reveal the spots by Method I.
mobile phase

ethyl acetate.

confirmation

By each method of visualisation the principal spot in the chromatogram obtained with solution (1) corresponds in position and colour to that in the chromatogram obtained with solution (2).

TESTS

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.

(1) Shake a quantity of the powdered tablets containing 10 mg of Cyclopenthiazide with 50 mL of acetone, filter, evaporate the filtrate to dryness and dissolve the residue in 2 mL of acetone.
(2) Dilute 1 volume of solution (1) to 100 volumes with acetone.
chromatographic conditions
(a) Use as the coating silica gel G.
(b) Use the mobile phase as described below.
(c) Apply 5 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in air and reveal the spots by Method I.
mobile phase

ethyl acetate.

limits

Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2).

Uniformity of content

Tablets containing less than 2 mg and/or less than 2% w/w of Cyclopenthiazide comply with the requirements stated under Tablets using the following method of analysis. To one tablet add 50 mL of methanol, shake for 20 minutes, filter and measure the absorbance of the filtrate at the maximum at 273 nm, Appendix II B. Calculate the content of C13H18ClN3O4S2 taking 585 as the value of A(1%, 1 cm) at the maximum at 273 nm.

Assay

Weigh and powder 20 tablets. Shake a quantity of the powder containing 7.5 mg of Cyclopenthiazide with 50 mL of methanol for 10 minutes and dilute to 100 mL with methanol. Mix, filter, dilute 20 mL of the filtrate to 100 mL with methanol and measure the absorbance of the resulting solution at the maximum at 273 nm, Appendix II B. Calculate the content of C13H18ClN3O4S2 taking 585 as the value of A(1%, 1 cm) at the maximum at 273 nm.