Table 4: Chemical stability of conjugates in physiological buffer at 24 h and rat plasma.

Polymeric conjugateMilliQ waterAcetate buffer pH 4.5Phosphate buffer pH 7.2 in rat plasma (min)

mPEG2000-glu-RSV>65%*>95%>40%3
mPEG2000-CL-glu-RSV>80%>95%>95%5
mPEG2000-PCL300-glu-RSVn/d**n/dn/d3
mPEG2000-PCL550-glu-RSVn/dn/dn/d3
mPEG2000-PCL1300-glu-RSVn/dn/dn/d3.5
mPEG2000-PCL5100-glu-RSV>80%>80%>85%4
mPEG2000-PCL9500-glu-RSV>95%>90%>90%10
mPEG2000-PCL13000-glu-RSV>35%>30%>40%8

Value represents percentage of original concentration at 24 h; **n/d: no data.