21 CFR § 640.103 - The final product.
(a) Final solution. The final product shall be a 16.5 ±1.5 percent solution of globulin containing 0.3 molar glycine and a preservative.
(b) Protein composition. At least 96 percent of the total protein shall be immunoglobulin G (IgG), as determined by a method that has been approved for each manufacturer by the Director, Center for Biologics Evaluation and Research, Food and Drug Administration.