How does using a micronized powder formulation affect the dissolution of a drug compared to large crystals?
Smaller particles have greater surface area exposed, leading to faster dissolution.
The physical form of a solid drug powder significantly dictates how quickly it can dissolve, even if the intrinsic chemical solubility remains constant. Micronization is the process of reducing particle size substantially. According to principles of physical chemistry, reducing particle size exponentially increases the total surface area exposed to the solvent. Since dissolution is fundamentally a surface phenomenon—the solvent molecules must interact with the drug surface to pull molecules into solution—a vastly increased surface area allows for a much faster dissolution rate when the drug is formulated as a micronized powder compared to larger, coarser crystals.
