Application of Quality by Design-based approach in development of liposomes as peptide carriers

Quality by Design (QbD) concepts were used in development of a liposome nanoformulation for peptide loading to nose to brain delivery. Ghrelin model agent, a peptide hormone with central nervous system functions, was used.
For QbD implementation, the quality target product profile was defined, critical factors (Table 1) were identified and initial risk analysis and Design of Experiments (26 experiments) were performed.
The prepared liposomes were evaluated according to liposomal size, polydispersity index, zeta potential and encapsulation efficiency.
The best combination of variables for liposome formation was 70 µg.ml-1 ghrelin, 8.3% cholesterol, 0.3% chitosan, solvent removal at 45ºC and 3 extrusions. Liposomes with particle size 135.09 ± 1.4 nm, with polydispersion index of 0.181 ± 0.018 and zeta potential 26.13 ± 3.25 mV were formed (Figure 1). Analysis of the results showed that these parameters remained stable within the deviations for two months.