Isophane Insulin Suspension
»Isophane Insulin Suspension is a sterile suspension of zinc-insulin crystals and Protamine Sulfate in buffered Water for Injection,combined in a manner such that the solid phase of the suspension consists of crystals composed of insulin,protamine,and zinc.The Protamine Sulfate is prepared from the sperm or from the mature testes of fish belonging to the genus OncorhynchusSuckley,or SalmoLinné(Fam.Salmonidae).Its potency,based on the sum of its insulin and desamido insulin components,is not less than 95.0percent and not more than 105.0percent of the potency stated on the label,expressed in USP Insulin Units per mL.
Packaging and storage— Preserve in the unopened multiple-dose container provided by the manufacturer.Do not repackage.Store in a refrigerator,protect from sunlight,and avoid freezing.
Labeling— Label it to indicate the one or more animal species to which it is related,as porcine,as bovine,or as a mixture of porcine and bovine.Where it is purified,label it as such.The Suspension container label states that the Suspension is to be shaken carefully before use.The label states the potency in USP Insulin Units per mL.Label it to state that it is to be stored in a refrigerator and that freezing is to be avoided.
Identification— It meets the requirements of the Identificationtest under Insulin Injection.
Bacterial endotoxins á85ñ— It contains not more than 80USP Endotoxin Units per 100USP Insulin Units.
Sterility á71ñ— It meets the requirements when tested as directed for Membrane Filtrationunder Test for Sterility of the Product to be Examined,the Suspension being filtered immediately after it has been reduced to a clear solution by the addition of a freshly prepared 1in 100solution of ascorbic acid in Fluid A.
pHá791ñ: between 7.0and 7.8,determined potentiometrically.
Zinc content á591ñ: between 10and 40µg for each 100USP Insulin Units.
Insulin in the supernatant—
Test solution— Centrifuge 10mLof the Suspension at 1500×gfor 10minutes.Use the supernatant.
Procedure— Determine the insulin content of the Test solutionby a suitable method:the insulin concentration is not more than 1.0USP Insulin Unit per mL.
Limit of high molecular weight proteins— Proceed as directed in the test for Limit of high molecular weight proteinsunder Insulin Injection:not more than 3.0%is found.
Assay— Proceed as directed in the Assayunder Insulin Injection.
Auxiliary Information— Staff Liaison:Larry N.Callahan,Ph.D.,Scientist
Expert Committee:(BNT)Biotechnology and Natural Therapeutics/Diagnostics
USP28–NF23Page 1025
Pharmacopeial Forum:Volume No.27(2)Page 2169
Phone Number:1-301-816-8385