Sulfadimethoxine Oral Suspension
»Sulfadimethoxine Oral Suspension contains not less than 90.0percent and not more than 110.0percent of the labeled amount of sulfadimethoxine (C12H14N4O4S).
Packaging and storage— Preserve in tight,light-resistant containers,and store at controlled room temperature.
Labeling— Label it to indicate that it is for veterinary use only.
Identification— Shake a quantity equivalent to about 50mg with 50mLof water,and add 2.5Nsodium hydroxide dropwise until the solution becomes clear.Add diluted hydrochloric acid dropwise until a precipitate forms.Collect the precipitate on a very fine filter,and wash it with water and with ether:the sulfadimethoxine so obtained meets the requirements for the Identificationtests under Sulfadimethoxine.
pHá791ñ: between 5.0and 7.0.
Assay—
Mobile phase,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Sulfadimethoxine.
Assay preparation— Transfer an accurately measured volume of Suspension,previously mixed and free from air bubbles,equivalent to about 50mg of sulfadimethoxine,to a 250-mLvolumetric flask,add about 200mLof Mobile phase,and swirl to dissolve.Dilute with Mobile phaseto volume,and mix.Protect this solution from light.
Procedure— Proceed as directed in the Assayunder Sulfadimethoxine.Calculate the quantity,in mg,of sulfadimethoxine (C12H14N4O4S)in each mLof the Oral Suspension taken by the formula:
250(C/V)(rU/rS),
in which Vis the volume,in mL,of Oral Suspension taken to prepare the Assay preparation;and the other terms are as defined therein.
Auxiliary Information— Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist
Expert Committee:(VET)Veterinary Drugs
USP28–NF23Page 1824
Pharmacopeial Forum:Volume No.27(2)Page 2198
Phone Number:1-301-816-8178