Determination of the entrapment efficiency in Thymopentin N-trimethyl chitosan nanoparticles

OBJECTIVE To determine the entrapment efficiency of thymopentin N-trimethyl chitosan nanoparticles in order to evaluate the quality of nanoparticles. METHODS The content of thymopentin in the supenatant was determined by HPLC after supercentrifugation under freezing temperature. The C 18 column was used as analytical column with the mobile phase consist of phosphate buffer(0.1 mol·ml -1, pH 7)-acetonirtrile(94∶6). RESULTS The linear range was 5-400 μg·ml -1. Recovery was 98.8% with RSD of 0.02. CONCLUSION The method is convenient,sensitive, accurate and suitable for determining the entrapment efficiency of thymopentin in the nanoparticles.