Packaging and storage— Preserve in well-closed containers.

Identification— Add the residue obtained in the Assay to 50 mL of water: the solution responds to the Identification tests under Methylcellulose.

Disintegration 701: 30 minutes.

Uniformity of dosage units 905: meet the requirements.

Residual solvents 467: meet the requirements.

Assay— Weigh and finely powder not less than 20 Tablets. Weigh accurately a portion of the powder, equivalent to about 500 mg of methylcellulose, and transfer to a tared, fine fritted-glass, low-form, 30-mL crucible having a fitted crucible lid. Add 20 mL of alcohol, and macerate the solid for about 5 minutes, mixing intermittently with a glass stirring rod. Repeat the extraction with ten consecutive 10-mL portions of alcohol. Test for completeness of extraction by evaporating the last alcohol extract on a steam bath to dryness, taking up the residue in about 1 mL of water, and adding this to 5 mL of hot alkaline cupric tartrate TS (no red precipitate of cuprous oxide is formed within 5 minutes). If a precipitate is formed, continue with the alcohol extractions until the test is negative. Wash the completely extracted residue with a 10-mL portion of ether, using suction to drain off the liquid. Dry the residue in the crucible in a drying oven at 105 to constant weight. Weigh the crucible with the crucible lid in place. The weight of residue is the weight of methylcellulose present in the portion of powdered Tablets taken.

Expert Committee : (MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine

USP29–NF24 Page 1395

Phone Number : 1-301-816-8251