Abstract
Purpose::
To compare the cytotoxicity levels of preservative-free Vitrase (hyaluronidase injection) Ovine 200 USP units/mL versus Amphadase (hyaluronidase injection) Bovine 150 USP units/mL containing up to 0.1 mg/mL of thimerosal (mercury derivative) using a Minimum Essential Media (MEM) Elution Assay with an L-929 mouse fibroblast cell line.
Methods::
Cell monolayers are grown to confluency, cell media was aspirated off and replaced with medium eluates of test samples and controls diluted 1:1 with MEM and then further diluted to 1:32 with MEM. Cell plates were then incubated at 37 degrees Celsius for 48 hours and examined for degree of cytotoxicity using United States Pharmacopeia (USP) Grading Scale: Grade 0, no reactivity, no cell lysis; Grade 1, slight reactivity, occasional lysed cells; Grade 2, mild reactivity, no extensive cell lysis; Grade 3, moderate reactivity, ≤ 70% of cell layer are lysed; Grade 4, severe reactivity, nearly complete cell layer destruction.
Results::
Vitrase was non-cytotoxic, with no cell lysis when tested undiluted at 1:1 and at dilutions from 1:2, 1:4, 1:8, 1:16, and 1:32. Amphadase was cytotoxic, with a score that represented nearly complete destruction of the cell layer (Grade 4) until the product was diluted to a 1:16 concentration. At 1:16 dilution, Amphadase produced a slight cytotoxic reaction (Grade 1).
Conclusions::
This study compared Vitrase and Amphadase using an L-929 mouse fibroblast cell line. Vitrase was non-cytotoxic, with no cell lysis when tested undiluted and at all dilutions tested. Amphadase was cytotoxic, with nearly complete destruction of the cell layer until 1:16 dilution. Currently, clinical significance of these data is unknown.