Infliximab stability after reconstitution, dilution, and storage under refrigeration.
OBJECTIVE
The purpose of this study was to investigate the stability of reconstituted infliximab solutions and determine whether infliximab is suitable for compounding for potential intravitreal use.


METHODS
Infliximab was reconstituted, and the solution was aliquoted and stored refrigerated. On each day of testing, an aliquot was serially diluted to concentrations ranging from 50,000 pg/mL to 69 pg/mL. Each dilution was assayed by microsphere immunoassay daily for 5 days and weekly for a total of 6 weeks. The outcome measure was median fluorescence intensity measured by dual laser flow analysis of fluorochrome-labeled secondary antibodies to infliximab bound to tumor necrosis factor-alpha-coated microspheres.


RESULTS
There was an increasing median fluorescence intensity for increasing infliximab concentration in a sigmoidal dose-response curve with a variable slope that was equivalent for each time point. Each respective concentration of infliximab showed nearly equivalent median fluorescence intensity for every time point over the 6-week period.


CONCLUSIONS
The authors found that the immunoreactivity of 2 different concentrations of infliximab stored at 4 degrees C over a 6-week period remained stable. Infliximab is suitable for compounding and could be a cost-effective intravitreal medication for use in clinical practice if further study supports its safety and efficacy.
Beer
Paul M
PM
Retina Consultants PLLC, Slingerlands, NY, USA. drbeer@retinaconsultants.org
Wong
Susan J
SJ
Schartman
Jerome P
JP
Kulas
Karen E
KE
Hartman
Coby L
CL
Giganti
Monica
M
Falk
Naomi S
NS
D000893:Anti-Inflammatory Agents / Q000737:chemistry* / Q000191:economics; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000191:economics; D002626:Chemistry, Pharmaceutical; D003362:Cost-Benefit Analysis; D004339:Drug Compounding; D016527:Drug Costs; D004355:Drug Stability; D004356:Drug Storage; D000069285:Infliximab; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
D000893:Anti-Inflammatory Agents; D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab