Analysis of diffusion of plant metabolites from polyethylene glycol hydrogels using free volume theory

The present work aims to comprehensively analyze the diffusion of plant metabolites from the polyethylene glycol (PEG) hydrogels for controlled release applications. For this study, a mathematical model based on free volume theory has been utilized to simulate the diffusion of low molecular weight plant metabolites. The results demonstrate that the mesh size of the crosslinked network, thereby the diffusion coefficient of the natural compound can be computed using the current framework. The proposed model has also been validated using the experimental data. The diffusion period has been observed to vary within a wide range of 3.42 h for Cinnamaldehyde to 49.25 h for Grandinin. An empirical parametric relationship between the diffusion time and molecular weight of both the hydrogels and natural compounds is established. It appears that the reported modeling approach will be clinically useful for improving the design of the sustained drug delivery systems.