Isophane Insulin Human Suspension
» Isophane Insulin Human Suspension is a sterile suspension of zinc-insulin human 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 human, protamine, and zinc. The Protamine Sulfate is prepared from the sperm or from the mature testes of fish belonging to the genus Oncorhynchus Suckley, or Salmo Linné (Fam. Salmonidae). Its potency, based on the sum of its insulin and desamido insulin components, as in the Assay, is not less than 95.0 percent and not more than 105.0 percent of the potency stated on the label, expressed in USP Insulin Human Units in each 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 The Suspension container label states that the Suspension is to be shaken carefully before use. The labeling states also that it has been prepared with Insulin Human of semisynthetic origin (i.e., derived by enzyme modification of pork pancreas insulin) or with Insulin Human of recombinant DNA origin (i.e., obtained from microbial synthesis), whichever is applicable. Label it to state that it is to be stored in a refrigerator and that freezing is to be avoided. The label states the potency in USP Insulin Units per mL.
USP Reference standards 11
USP Endotoxin RS
Identification The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.
Bacterial endotoxins 85 It contains not more than 80 USP Endotoxin Units per 100 USP Insulin Human Units.
Sterility 71 It meets the requirements when tested as directed for Membrane Filtration under Test for Sterility of the Product to be Examined, and the Suspension being filtered immediately after it has been reduced to a clear solution by the addition of a freshly prepared 1 in 100 solution of ascorbic acid in Fluid A.
pH 791: between 7.0 and 7.5, determined potentiometrically.
Zinc content 591: between 0.021 mg and 0.04 mg for each 100 USP Insulin Human Units.
Insulin in the supernatant
Test solution Centrifuge 10 mL of the Suspension at 1500 × g for 10 minutes. Use the supernatant.
Procedure Determine the insulin content of the Test solution by a suitable method: the insulin concentration is not more than 1.0 USP Insulin Human Unit per mL.
Limit of high molecular weight proteins Proceed as directed in the test for Limit of high molecular weight proteins under Insulin Injection: not more than 3.0% is found.
Assay Proceed as directed in the Assay under Insulin Human Injection.
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3511Pharmacopeial Forum: Volume No. 36(6) Page 1539