Microfluidic fabrication of pectin-coated liposomes for drug delivery.

Polymer coating of nanoparticulate drug delivery systems may enhance the efficacy of oral delivery. Cationic liposomes were coated with pectin biopolymers using microfluidics, with systematic variation of process parameters to optimize pectin-coated liposome fabrication. A pectin/liposome weight ratio of 0.7 and a microfluidic flow rate ratio of 2:1 pectin:liposome were found to be optimal. The resulting formulations displayed particle sizes at least threefold the size of uncoated liposomes, while the surface charge shifted to a highly negative value, indicating full pectin coating of the particles. Further microscopic characterization of the pectin-coated liposomes revealed that the pectins formed a polymeric network within which the liposomes were dispersed or attached. Stability studies revealed that pectin-coated liposomes remained stable during storage, with no displacement of the coating. We determined that microfluidics is a robust method for preparing pectin-coated liposomes, despite the structural differences between the pectins, geometry of the microchip used, and pectin/liposome concentration. Ultimately, the use of microfluidics in formulation development could be highly beneficial, as the process parameters can be easily modified and the process is easily scalable and inexpensive. Additionally, pectins can offer protective properties to the liposomes particularly during oral drug delivery.