Barium Sulfate Paste
» Barium Sulfate Paste is a semisolid formulation of finely divided particles of Barium Sulfate in a suitable base. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of barium sulfate (BaSO4). It may contain one or more suitable colors, flavors, suspending or dispersing agents, and preservatives.
Packaging and storage— Preserve in tight containers, protected from freezing and from excessive heat.
Identification— Ignite an accurately weighed quantity of Paste, equivalent to about 0.5 g of barium sulfate, to constant weight: the ignited residue meets the requirements for Identification tests A and B under Barium Sulfate.
Microbial enumeration tests 61 and Tests for specified microorganisms 62 For products labeled for oral administration or labeled for oral and rectal administration, the total aerobic microbial count does not exceed 100 cfu per g, and the total combined molds and yeasts count does not exceed 10 cfu per g. For products labeled for rectal administration, the total aerobic microbial count does not exceed 1000 cfu per g, and the total combined molds and yeasts count does not exceed 100 cfu per g. For all products, it meets the requirements of the tests for absence of Salmonella species, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, and the total enterobacterial count does not exceed 10 cfu per g.
pH 791: between 3.0 and 10.0.
Assay— Using Paste, proceed as directed in the Assay under Barium Sulfate for Suspension.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ian DeVeau, Ph.D.
Director, Veterinary Drugs and Radiopharmaceuticals
1-301-816-8178
(RMI05) Radiopharmaceuticals and Medical Imaging Agents 05
61 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
1-301-816-8339
(MSA05) Microbiology and Sterility Assurance
62 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
1-301-816-8339
(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 1629