4.6. Stability of Liposome

To examine the stability of the liposomes, liposome solutions were kept in 4 °C storage conditions, and particle size variations were measured at different time points. SA-5-Dox-LP and Dox-LP were stored for 30, 60, and 90 days successively measured for particle size variation. In addition, in vitro serum stability was carried out according to the previously described method [61]. Briefly, human serum was centrifuged, and the supernatant was filtered with a 1 µm syringe filter to remove any suspended particles. SA-5-Dox-LP and Dox-LP solution was mixed with human serum at a 1:3 ratio and incubated at 37 °C for 0, 24, and 48 h successively. Finally, the particle size was measured at different time points (0, 24, and 48 h successively). 200 µL of the sample was taken and appropriately diluted with distilled H₂O at different time points and analyzed in the particle size analyzer. Three replicates were analyzed for each sample type in each time point. From a single stored stability solution in a particular condition, samples were taken in different time points and measured for stability assessment.