Layer-by-layer coated microcapsules with lipid nanodomains for dual-drug delivery

Microcapsules (MCs), prepared using colloidal particles as shell material for assembly, are a drug-delivery system offering several advantages such as increased drug encapsulation efficiency, higher surface area, modifiable structure, and multi-functionality. Nano-in-micro ibuprofen (IBU) MCs were prepared using the layer-by-layer method for use as controlled, dual-drug delivery agents with adjustable release kinetics. Drug-release kinetics may be adjusted by using solid lipid nanoparticles (SLN) to create a negatively charged shell and gold nanoparticles and chitosan as positively charged shells. Ascorbic acid (AA) was used as the model drug and loaded into SLNs during the preparation of the particles. The deposition of layers was confirmed by the reversal of zeta-potentials. Transmission electron microscopy confirmed the integrity of IBU-MCs after the release of the IBU core. UV-vis spectroscopy was used to observe the release of AA and IBU at pH 6.8 (simulated intestinal fluid without enzymes). The kinetic model of the release rate as well as the release profile of IBU from these MCs is dependent on the shell composition and capsule thickness. The release rate of AA may be controlled and substantially prolonged by adjusting the placement of AA-loaded SLNs as the shell material. This study could improve personalized and customizable dual-drug delivery systems by providing various advantages over existing systems. These advantages include presence of physiologically related lipids, biocompatibility, a small and modifiable structure, high surface area, multi-functionality, increased encapsulation efficiency, and separate compartments for the entrapment of multiple drugs.