Dana E. Moseson, PhD

Product stability is required to transform a molecule into a medicine for safe and efficacious delivery to patients. Amorphous materials are advantageous to improve solubility and dissolution rate of poorly soluble compounds; however, they have a thermodynamic driving force for crystallization. Upon recrystallization, the solubility advantage is lost, which is highly detrimental to bioavailability. Atomic layer deposition (ALD) is a layer-by-layer technique in which a nanoscale film of biocompatible metal oxide (commonly <10-100 nm) is applied to the surface of a substrate with excellent control of conformality and film thickness. The overall goal of this research is to identify the mechanistic factors required for successful implementation of ALD coatings for improved physical stability of amorphous pharmaceutical products. First, we will demonstrate that ALD coatings can improve physical stability of amorphous materials (i.e., inhibit surface crystallization). Model systems were selected to vary their chemistry to evaluate the mechanisms by which the ALD coating can improve physical stability. Next, we will examine performance attributes of ALD-coated particles and formulations: 1) dissolution performance of coated and uncoated particles and 2) physical stability following compression. Successful completion of this research will lead to enhanced understanding of ALD technology applications within pharmaceutical drug delivery to address product stability questions.