Process For Physicochemical Improvement Of Ultra-Flexible Liposomes Loaded With Insulin

The objective of this work was to evaluate physicochemical characteristics of ultra-flexible liposomes obtained by two manufacturing methods with sucrose as hydrating agent, the thin-film rehydration method and the heating method, with a focus on improvement of percent entrapped insulin. Four formulations were prepared by each method with different percentages of soy L-alpha-phosphatidylcholine and sodium cholate. Size distribution, polydispersity index, zeta potential and encapsulation percentage were evaluated. The ultraflexible liposomes obtained using the heating method showed smaller size, better homogeneity, adequate surface charge and higher encapsulation percent compared with traditional liposomes and those obtained using the thin-film rehydration method. Additionally, insulin was found to be stable after the formulation processes according to polyacrylamide gel electrophoresis and differential calorimetry scanning, indicating that the temperature used in these techniques did not affect the stability of this protein.