Limit of tyrosine
Transfer an accurately measured volume,equivalent to about 120USP Hyaluronidase Units,to a 15-mLcentrifuge tube calibrated at 6mL,and evaporate at 105

to dryness.Proceed as directed in
Limit of tyrosineunder
Hyaluronidase for Injection,beginning with Add 200µLof 6Nsodium hydroxide,except to read Hyaluronidase Injection for Hyaluronidase for Injection in the second paragraph.Calculate the quantity,in µg,of tyrosine in the volume of Injection taken by the formula:
45(AU/AS),
in which
AUand
ASare the absorbances of the solution from the Injection and the Standard solution,respectively:not more than 0.25µg of tyrosine is found for each USP Hyaluronidase Unit.
Assay
Acetate buffer solution,Phosphate buffer solution,Hydrolyzed gelatin,Diluent for hyaluronidase solutions,Serum stock solution,Serum solution,Potassium hyaluronate stock solution,Hyaluronate solution,and Standard solution
Prepare as directed in the
Assay under
Hyaluronidase for Injection.
Assay preparation
Quantitatively dilute an accurately measured volume of Injection with cold Diluent for hyaluronidase solutions,on the basis of trial or experience,so that the observed absorbances with the three dilutions of the Injection fall on the upper,linear part of the standard curve prepared as directed in the Procedure.
Procedure
Proceed as directed for
Procedurein the
Assay under
Hyaluronidase for Injection.The potency,in USP Hyaluronidase Units,of the portion of Injection taken is the average of the six activity values read from the standard curve.