High shear processes have been used to reduce the size and homogenize the size distribution of liposomes in their scalable production. However, high shear rates modify the liposome structure, which may affect the loading of hydrophobic drugs. This work aimed to study the influence of shearing on the...

High shear processes have been used to reduce the size and homogenize the size distribution of liposomes in their scalable production. However, high shear rates modify the liposome structure, which may affect the loading of hydrophobic drugs. This work aimed to study the influence of shearing on the elasticity of liposomes and its effects on the incorporation of CH8 nitrochalcone, a highly hydrophobic drug indicated to treat cutaneous leishmaniasis. The liposomes were composed of egg phosphatidylcholine. They were produced and sized in a single step by ethanol injection under shearing with a Cowles impeller and an Ultra Turrax®. Small angle X-ray scattering spectra showed that the shearing reduced the interlamellar distance of the liposomes. The interlamellar distance did not change with the shearing intensity in the range of Cowles stirring, but it decreased for higher shearing provided by the Ultra Turrax®. The elastic constant, which is related to the stiffness of the bilayer and depends on the structure of the liposomes, increased with increasing shearing intensity for both stirrers. The shearing also reduced the mean diameter of the liposomes and the size distributions. The lowest shearing, provided by the Cowles stirrer, was beneficial for the elasticity and the loading of CH8 in the liposomes. Therefore, the elasticity of the bilayer is a determining factor for the loading of hydrophobic drugs in liposomes

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