1.4.3 Stability Studies The stability of ranibizumab alone and in combination with verteporfin was assessed in vitro. The combination of ranibizumab and verteporfin in a 5% dextrose solution at concentrations of 500 mg/mL and 1.4 mg/mL, respectively, resulted in ranibizumab degradation and a decrease in ranibizumab capacity to bind VEGF. The ranibizumab degradation products have not been fully characterized. Although it is currently unknown if such degradation also occurs in vivo, sequential administration of verteporfin followed by ranibizumab with an intervening washout period will decrease the likelihood of loss of ranibizumab activity and degradation.