Summary
Amorphous solid dispersions (ASD) for nasal delivery offer the opportunity to increase drug release performance, while using polymers with mucoadhesive properties. In spite of the current knowledge on formulation and characterization of nasal powders, scarce studies evaluate the potential of ASD. Additionally, the lack of translation between different in vitro methodologies and the lack of correlations between in vitro and in vivo results compromise the accurate and effective development of nasal powders. Herein, spray dried ASD were manufactured using piroxicam (PXC) as a poorly soluble drug model and evaluated regarding in vitro drug release and ex vivo permeation through porcine nasal mucosa in Franz diffusion cells. Additionally, in vivo pharmacokinetic studies were carried out in Wistar rats. The results indicated that ASD for nasal delivery of poorly soluble drugs could be a suitable strategy to provide a faster onset of action. Pharmacokinetic parameters were correlated with in vitro and ex vivo parameters, where high coefficients of determination were obtained, especially for early timepoints (R2 > 0.90). This indicates that the methods employed are biorelevant and provide valuable insights into drug nasal absorption.