Dexamethasone loaded liposomes by thin‐film hydration and microfluidic procedures: Formulation challenges

Liposomes have been one of the most exploited drug delivery systems in recent decades. However, their large‐scale production with low batch‐to‐batch differences is a challenge for industry, which ultimately delays the clinical translation of new products. We have investigated the effects of formulation parameters on the colloidal and biopharmaceutical properties of liposomes generated with a thin‐film hydration approach and microfluidic procedure. Dexamethasone hemisuccinate was remotely loaded into liposomes using a calcium acetate gradient. The liposomes produced by microfluidic techniques showed a unilamellar structure, while the liposomes produced by thin‐film hydration were multilamellar. Under the same remote loading conditions, a higher loading capacity and efficiency were observed for the liposomes obtained by microfluidics, with low batch‐to‐batch differences. Both formulations released the drug for almost one month with the liposomes prepared by microfluidics showing a slightly higher drug release in the first two days. This behavior was ascribed to the different structure of the two liposome formulations. In vitro studies showed that both formulations are non‐toxic, associate to human Adult Retinal Pigment Epithelial cell line‐19 (ARPE‐19) cells, and efficiently reduce inflammation, with the liposomes obtained by the microfluidic technique slightly outperforming. The results demonstrated that the microfluidic technique offers advantages to generate liposomal formulations for drug‐controlled release with an enhanced biopharmaceutical profile and with scalability.