Table 3.

Analysis of Last 3 Years of Returned Insulin Samples (233 Vials) From US Patients.

Product	Average assay (IU/ml)	SD	Sample size
Actrapid	98.5	6.7	58
Insulatard	98.5	2.4	175
All products above	98.5	3.9	233

Only five vials, four of Insulatard and one of Actrapid, fell below 95 U/ml. The four vials on Insulatard had at least 50% of insulin removed and had evidence of inhomogeneous extraction (inadequate mixing). The contents of the vial of Actrapid had evidence of contamination with another liquid. All data were included in the analyses above, as also indicated by the standard deviations.