3.2. Drug content and water solubility
It was tested that free Mel and Mel-OCM-chitosan conjugates
have the same UV absorption characteristic and both showed an
absorption peak at around 261 nm. Table 1 shows the Mel content
in all Mel-OCM-chitosan conjugates. Keeping OCM-chitosan
feed ratio unchanged, it was found that Mel content in Mel-OCMchitosan
conjugates decreased from 15.9 to 11.9, Mel substitution
degree decreased from 0.147 to 0.107, as the spacer changed from
Gly to Leu. The result indicated that selection of amino acid spacer
played an important role in adjusting Mel content