Tunable dissolution of poorly soluble gliclazide by surface coating via room-temperature atomic layer deposition

Gliclazide (GLZ) is a sulfonylurea antidiabetic drug widely used to treat type 2 diabetes mellitus. However, its poor aqueous solubility is a major challenge in drug formulation, often limiting the bioavailability and therapeutic efficacy. In this study, we explore the application of atomic layer deposition (ALD) as a surface engineering technique to enhance the wettability and tailor the dissolution of GLZ. By coating the drug particles with ultra-thin SiO2 films, their wettability is transformed from strongly hydrophobic to highly hydrophilic, promoting a highly dispersed state in an aqueous medium and significantly accelerating the dissolution. More importantly, by controlling the coating thickness, the dissolution rate of GLZ can be tailored, enabling tunable drug dissolution profiles. The results demonstrate the potential of SiO2 ALD not only in overcoming solubility-related limitations but also in providing a method of multipurpose design for controlled drug delivery. Given its compatibility with pharmaceutical manufacturing, our approach presents a promising pathway to enhance bioavailability and optimize the release kinetics of other poorly soluble drugs.