Hemp Therapies Wiki / Liposomal Delivery Systems

How Liposomes Are Manufactured

Liposomes can be manufactured through several distinct methods, each producing particles with different size, structure, and encapsulation characteristics.

Production Methods

Thin-film hydration, also called the Bangham method, is a foundational process in which lipids are dissolved in an organic solvent, the solvent is evaporated to leave a thin lipid film on a vessel surface, and the film is then rehydrated with an aqueous solution. This initially produces multilamellar structures, which can be reduced in size and bilayer count through subsequent sonication or extrusion. Sonication uses high-frequency sound waves to break larger lipid structures into small unilamellar vesicles, though the method is difficult to scale to industrial batch sizes and can introduce trace metal contamination from the sonicator probe. Ethanol injection disperses a lipid-and-ethanol solution rapidly into an aqueous phase, and is noted for simplicity, speed, and avoidance of lipid oxidation, tending to directly generate small unilamellar vesicles. Reverse-phase evaporation first forms a water-in-oil emulsion, then removes the organic solvent under reduced pressure, and is generally associated with encapsulating larger or higher-molecular-weight compounds.

Microfluidic processing forces lipid and aqueous streams through narrow channels under controlled conditions, producing batches with more consistent particle size and bilayer structure than manual sonication. Supercritical carbon dioxide processing is a solvent-free method reported to produce higher encapsulation efficiency than some conventional methods, at a higher relative production cost. High-pressure homogenization forces a lipid mixture through a narrow valve under high pressure to reduce particle size, and is also used to manufacture related nanostructured lipid carriers. Freeze-thaw cycling is sometimes applied after initial liposome formation to change how much of a target compound becomes encapsulated.

Loading Methods

In “passive loading,” a water-soluble ingredient is present in the aqueous solution during bilayer formation and becomes trapped inside as the sphere closes, while fat-soluble ingredients instead partition into the lipid wall itself. In “active” or “remote” loading, liposomes are formed first, and a chemical gradient, such as a pH difference across the membrane, is then used to draw a target compound into the already-formed liposome.

Production Timelines

Contract manufacturers in the supplement industry report liposomal production timelines of roughly four to six weeks for a white-label batch, from formulation to finished goods.

Summary

Liposome manufacturing methods trade off differently between production scale, particle consistency, and cost, and the loading method used — passive or active — depends on whether the target ingredient is water-soluble or fat-soluble.