U.S. PHARMACOPEIA

Search USP29  
Saccharin Calcium
Click to View Image
C14H8CaN2O6S2·3½H2O 467.49

1,2-Benzisothiazol-3(2H)-one, 1,1-dioxide, calcium salt, hydrate (2:7).
1,2-Benzisothiazolin-3-one 1,1-dioxide calcium salt hydrate (2:7) [6381-91-5].

Anhydrous 404.44 [6485-34-3].
» Saccharin Calcium contains not less than 98.0 percent and not more than 101.0 percent of C14H8CaN2O6S2, calculated on the anhydrous basis.
Packaging and storage— Preserve in well-closed containers.
Labeling— Where the quantity of saccharin calcium is indicated in the labeling of any preparation containing Saccharin Calcium, this shall be expressed in terms of saccharin (C7H5NO3S).
Identification—
A: Dissolve about 100 mg in 5 mL of sodium hydroxide solution (1 in 20), evaporate to dryness, and gently fuse the residue over a small flame until it no longer evolves ammonia. Allow the residue to cool, dissolve in 20 mL of water, neutralize with 3 N hydrochloric acid, and filter: the addition of a drop of ferric chloride TS to the filtrate produces a violet color.
B: Mix 20 mg with 40 mg of resorcinol, add 10 drops of sulfuric acid, and heat the mixture in a suitable liquid bath at 200 for 3 minutes. Allow it to cool, and add 10 mL of water and an excess of 1 N sodium hydroxide: a fluorescent green liquid results.
C: A solution (1 in 10) meets the requirements of the tests for Calcium 191.
D: To 10 mL of a solution (1 in 10) add 1 mL of hydrochloric acid: a crystalline precipitate of saccharin is formed. Wash the precipitate with cold water, and dry at 105 for 2 hours: it melts between 226 and 230, the procedure for Class I being used (see Melting Range or Temperature 741).
Water, Method I 921: not more than 15.0%.
Readily carbonizable substances 271— Dissolve 200 mg in 5 mL of sulfuric acid TS, and maintain at a temperature of 48 to 50 for 10 minutes: the solution has no more color than Matching Fluid A.
Selenium 291: 0.003%.
Toluenesulfonamides—
Internal standard solution, Standard stock solution, and Standard preparations— Prepare as directed for Internal standard solution, Standard stock solution, and Standard preparations in the test for Toluenesulfonamides under Saccharin (see NF monograph).
Test preparation— Prepare as directed under Column Partition Chromatography (see Chromatography 621), employing a chromatographic tube fitted with a porous glass disk in its base, a plastic stopcock on the delivery tube, and a reservoir on the top. Add a mixture consisting of 10 g of Solid Support and a solution of 2.0 g, accurately weighed, of Saccharin Calcium in 8.0 mL of sodium carbonate solution (1 in 20), and proceed as directed for Test preparation in the test for Toluenesulfonamides under Saccharin (see NF monograph), beginning with “Pack the contents.”
Chromatographic system and Procedure— Proceed as directed for Chromatographic system and Procedure in the test for Toluenesulfonamides under Saccharin (see NF monograph).
Heavy metals, Method I 231— Dissolve 4 g in 46 mL of water, add 4 mL of dilute hydrochloric acid (1 in 12), mix, and rub the inner wall of the vessel with a glass rod until crystallization begins. Allow the solution to stand for 1 hour, then pass through a dry filter, discarding the first 10 mL of the filtrate, and use 25 mL of the subsequent filtrate for the Test Preparation: the limit is 0.001%.
Limit of benzoate and salicylate— To 10 mL of a solution (1 in 20), previously acidified with 5 drops of 6 N acetic acid, add 3 drops of ferric chloride TS: no precipitate or violet color appears.
Organic volatile impurities, Method I 467: meets the requirements.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay— Accurately weigh about 500 mg of Saccharin Calcium, and transfer completely to a separator with the aid of 10 mL of water. Add 2 mL of 3 N hydrochloric acid, and extract the precipitated saccharin first with 30 mL, then with five 20-mL portions, of a mixture of chloroform and alcohol (9:1). Evaporate the combined extracts on a steam bath to dryness, with the aid of a current of air, then dissolve the residue in 40 mL of alcohol, add 40 mL of water, mix, add phenolphthalein TS, and titrate with 0.1 N sodium hydroxide VS. Perform a blank determination on a mixture of 40 mL of alcohol and 40 mL of water, and make any necessary correction. Each mL of 0.1 N sodium hydroxide is equivalent to 20.22 mg of C14H8CaN2O6S2.
Auxiliary Information— Staff Liaison : Catherine Sheehan, B.Sc., Scientist
Expert Committee : (EM105) Excipient Monographs 1
USP29–NF24 Page 1937
Pharmacopeial Forum : Volume No. 31(2) Page 609
Phone Number : 1-301-816-8262