Why does it appear that there is visible sediment in the master vial?
Multiple diluent solutions are utilized for formulating allergy immunotherapy vials for use in allergic patients. These diluents include both normal saline (NSP) and human serum albumin (HSA). NSP is comprised of a salt, buffered solution containing phenol (0.4%), while HSA is formulated using this same NSP solution with an additional human serum albumin (0.03%) component. The human serum albumin is a non-specific protein addition, which allows for the diluent to have an increased protein concentration, enabling improved allergen stability. Both diluent formulations contain 0.4% phenol, which functions as a bacteriostatic agent to prevent microbial growth. On occasion, NSP and HSA will contain small particulate matter. While this phenomenon occurs infrequently, investigations into the nature and cause of these events have been conducted. Chemical analyses of precipitated lots of both diluents have been performed. No gross change in chemical composition has been observed in either diluent containing precipitation. Additional circumstances for precipitation are observed in HSA diluent vials, independent of phenol-related discoloration. As previously discussed, HSA is a non-specific protein utilized to increase the protein concentration of an allergy diluent. The appearance of HSA-related precipitant is translucent, globular, filament-like and has been found to be harmless. If you observe particulates outside of what is described above, please contact the Customer Service Team for further guidance.