Preparation, characterization, and in vitro efficacy of
O-carboxymethyl chitosan conjugate of melphalan
Bo Lu, Dan Huang, Hua Zheng∗, Zhijun Huang, Peihu Xu, Haixing Xu, Yihua Yin, Xia Liu,
Dan Li, Xueqiong Zhang
Department of Pharmaceutical Engineering, School of Chemical Engineering, Wuhan University of Technology, Wuhan 430070, PR China
a r t i c l e i n f o
Article history:
Received 25 March 2013
Received in revised form 23 April 2013
Accepted 24 April 2013
Available online 14 May 2013
Keywords:
Melphalan
Carboxymethyl chitosan
Polymeric prodrug
a b s t r a c t
A series of melphalan-O-carboxymethyl chitosan (Mel-OCM-chitosan) conjugates with different spacers
were prepared and structurally characterized. All conjugates showed satisfactory water-solubility (160-
217 times of Mel solubility). In vitrodrug release behaviors by both chemical and enzymatic hydrolysis
were investigated. The prodrugs released Mel rapidly within papain and lysosomal enzymes of about
40–75%, while released only about 4–5% in buffer and plasma, which suggested that the conjugates have
good plasma stability and the hydrolysis in both papain and lysosomes occurs mostly viaenzymolysis.
It was found that the spacers have important effect on the drug content, water solubility, drug release
properties and cytotoxicity of Mel-OCM-chitosan conjugates. Cytotoxicity studies by MTT assay demonstrated
that these conjugates had 52–70% of cytotoxicity against RPMI8226 cells in vitro as compared
with free Mel, indicating the conjugates did not lose anti-cancer activity of Mel. Overall these studies
indicated Mel-OCM-chitosan conjugates as potential prodrugs for cancer treatment.