Liposomes are being used to deliver a number of different active pharmaceuticals for both small and large molecule API’s. Traditional liposome preparation methods include detergent depletion, ethanol injection, reverse-phase evaporation and emulsification. Processing methods include high-pressure homogenization, extrusion, and conventional ultrasound. The major disadvantages of these preparation methods include the consumption of large volumes of volatile organic solvents, multiple lengthy steps and degradation of the sample, and subsequent loss of bioactivity, due to heat exposure.
Adaptive Focused Acoustics™ (AFA) technology offers a breakthrough alternative to traditional methods, by forming monodisperse liposomes at 4°C (below the lipid phase transition temperature) and eliminating the need to use organic solvents.
Fully scalable from 100µL to continuous flow manufacturing, AFA-Liposome formation is possible across a range of lipids and formulations, including the addition of cholesterol and other difficult to load materials. Active ingredients can be loaded into the AFA-liposome at the time of formation, allowing a very simple and effective, one step formulation within a matter of minutes, without the risk of cross contamination or the need to cleanup.
Making unilamellar liposomes using focused ultrasound. Tejera-Garcia et al. 2011. Langmuir 27:10088-97. In this paper scientists from Aalto University in Finland used Covaris AFA to form liposomes and they reconfirmed that the Covaris technology “provides a simple and easy to use approach for making liposomes with several advantages: it is minimally invasive and involves no loss of material. Precisely controlled wavelengths are employed with a significant reduction in the presence of hot spots, which could destroy some biological materials of interest.” http://www.ncbi.nlm.nih.gov/pubmed/?term=21740027
Oxidized phosphatidylcholines facilitate phospholipid flip-flop in liposomes. Volinsky et al. 2011. Biophysical Journal 101:1376-84. In this paper, the authors used Covaris AFA technology for making single unilamellar vesicles. http://www.ncbi.nlm.nih.gov/pubmed/?term=PMC3177064
Peptide-mediated targeting of liposomes to TrkB receptor-expressing cells. Ranjan et al. 2012. International Journal of Nanomedicine 7: 3475–85. In this paper, the authors used Covaris AFA technology in the incorporation of peptide-PEG-lipid conjugates into liposomes after the organic solvent evaporation step. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3405886/
Freeze Fracture Electron Microscopic Examination of Liposomes Produced by Covaris AFA Technology. Kakumanu and Jain 2013. Drug Delivery Technology 13:46-50. In this paper, Covaris researchers analyze the structure of liposomes produced by AFA using ffEM. Covaris’ Liposome Preparation Technology
Sensitivity of nanostructure in charged cubosomes to phase changes triggered by ionic species in solution. Liu et al. 2013. Langmuir 29:14265-73. Scientists used a Covaris instrument with mixed lipid systems in this article. http://pubs.acs.org/doi/pdf/10.1021/la402426y