Laboratory scale production of injectable liposomes by using cell disruptor to avoid the probe sonication process

Multilamellar vesicle (MLV)-type liposomes are promising carriers for hydrophobic drugs that need to be injected. In MLV preparation process, probe sonication step is often required to obtain liposomes fulfilling the mean particle size and polydispersity index (PI) requirements as an injectable lipid formulation. However, it is often limited by the risk of sample overheating. This study was undertaken to explore a possibility of using cell disruptor in the liposome preparation process as an alternative sonication method. Use of cell disruptor-type sonicator decreased the mean particle size and PI of liposomes much more effectively compared to conventional bath sonicators. The effectiveness of cell disruptor sonicator in decreasing the size and PI of liposomes was comparable to that of probe sonicator, particularly in the presence of a hydrophobic drug celecoxib. Sonication of liposomes by a cell disruptor sonicator produced celecoxib-loaded liposomes exhibiting 152 ± 9 nm mean particle size with a PI of 0.155, indicating a very homogenous and fine dispersion. Together with its proved efficacy in increasing the homogeneity, the advantage of cell disruptor sonicator includes the minimal exposure of liposome samples to heat, thereby providing an efficient method to prepare injectable liposomes at a laboratory scale.