Packaging and storage— Preserve in well-closed containers.

Labeling— Label Methenamine Mandelate for Oral Solution that contains insoluble ingredients to indicate that the aqueous constituted Oral Solution contains dissolved methenamine mandelate,but may remain turbid because of the presence of added substances.

USP Reference standards á11ñ— USP Methenamine Mandelate RS.

Identification— Afinely powdered portion,equivalent to about 100mg of methenamine mandelate,responds to the Identificationtest under Methenamine Mandelate Oral Suspension.

Uniformity of dosage units á905ñ—

Deliverable volume á698ñ

pHá791ñ: between 4.0and 4.5,in a mixture of 1g with 30mLof water.

Water,Method Iá921ñ: not more than 0.5%.

Assay— Accurately weigh the contents of not fewer than 10containers of Methenamine Mandelate for Oral Solution,and reduce to a fine powder.Transfer an accurately weighed portion of the powder,equivalent to about 60mg of methenamine mandelate,to a 150-mLbeaker.Add 15mLof dehydrated alcohol,stir to dissolve,and proceed as directed in the Assayunder Methenamine Mandelate,beginning with “add 40mLof chloroform.”

Expert Committee:(PA7)Pharmaceutical Analysis 7

USP28–NF23Page 1243

Phone Number:1-301-816-8394