Preparation of lomustine-iohexol thermosensitive compound liposomes and study on the in vitro release characteristics

To prepare lomustine-iohexol thermosensetive compound liposomes, and evaluate the properties and in vitro release behaviors of two drugs enveloped. Lomustine-iohexol thermosensetive compound liposomes were prepared by reverse evaporation method, HPLC assays for determination of lomustine and iohexol in vitro were developed, and their release property was studied by using dislysis method. The mean diameter of thermosensitive liposomes was 266.4 nm, Zeta potential was -21.8mV, and phase-transition temperature was 4l°C. The HPLC assays developed were specific, rapid and reliable, which can be used to determine lomustine and iohexol in vitro accurately. In vitro release tests showed that lomustine and iohexol were released more entirely at 4l°C. The release profile of iohexol from liposomes at 4l°C fitted to First-order kinetics model with the equation of ln(100-Q)=-1.066t-0.0498 (r=0.9993), whereas the release profile of lomustine from liposomes at 4l°C fitted to Weibull model with the equation of lg[-ln(100-Q)]=1.1069lgt-0.0976 (r=0.9923). The formulation and preparation method can be successfully prepared lomustine-iohexol thermosensitive compound liposomes with good thermal-sensitive release behaviors of both drugs.