Dual Centrifugation - A Novel “in-vial” Liposome Processing Technique

Abstract

Conventional liposome preparation methods bear many limitations, such as poor entrapment efficiencies for hydrophilic drugs, batch size limitations, and limited options for aseptic manufacturing. Liposome preparation by dual centrifugation (DC) is able to overcome most of these limitations. DC differs from normal centrifugation by an additional rotation of the samples during the centrifugation process. Thus, the direction of the centrifugal forces changes continuously in the sample vials. The consequential powerful sample movements inside the vials result in powerful homogenization of the sample. Since this "in-vial" homogenization is optimal for viscous samples, semisolid "vesicular phospholipid gels" (VPGs) are preferred intermediates in the liposome manufacturing by DC. The DC method easily enables aseptic preparation and is gentler as compared to other methods, such as high-pressure homogenization. The method allows very small samples to be prepared, and VPG batches down to 1-5 mg scale have been prepared successfully. VPGs have several applications; they are attractive as depot formulations, or as stable storage intermediates, and can be easily transferred into conventional liposomal formulations by simple dilution. Here, we aim to present the novel DC-liposome technique; the concept, advantages, and limitations; and provide an overview of the experiences of liposome preparation by DC so far.

Stability of Alkyl Chain-Mediated Lipid Anchoring in Liposomal Membranes

“…The advantages of using dual centrifugation to produce liposomal formulations are the choice of flexible preparation sizes with simultaneous sterile and endotoxin-free conditions. In addition, this cost-effective method allows for the simultaneous preparation of several samples [ 26 , 42 ].…”

Preclinical In Vitro Studies with 3D Spheroids to Evaluate Cu(DDC)2 Containing Liposomes for the Treatment of Neuroblastoma

“…This includes the transfer of the liposome preparation process from lab scale to large scale. Different preparation techniques, such as high pressure homogenization [ 48 ], microfluidization [ 49 ], cross flow filtration [ 50 ], or dual asymmetric centrifugation [ 51 , 52 ] can be implemented for the production of large volumes of Cu 2+ liposomes. Formation of Cu(DDC) 2 complexes inside the liposomes and separation of non-encapsulated material may be achieved by using industrial high throughput columns and high pressure filtration under aseptic conditions.…”

Lipid Delivery Systems for Nucleic-Acid-Based-Drugs: From Production to Clinical Applications

“…In 2011, also Adrian and collaborators have used the DAC method to produce liposomes containing siRNA, targeting the particles surface with an antibody for the selective interaction with neuroblastoma cells, achieving 190 to 240 nm particles with siRNA encapsulation efficiency of up to 50% [85]. By this technique, in only one step, sterile SUVs formulations in a highly reproducible manner can be prepared [86].…”