Diffusion, permeation, and solubility of selected agents in and through polyethylene

Even though polyethylene containers have and are being used with more frequency to package drug products, diagnostic agents, biological products, and cosmetic preparations, little emphasis apparently has been placed on the possible interactions between solute molecules in the product and the polyethylene. This report presents a study on the diffusion, permeation, and solubility of six compounds (acetophenone, benzaldehyde, benzoic acid, benzyl alcohol, 4-methylacetophenone, and 4-methylbenzaldehyde) in and through polyethylene. Results reveal that benzyl alcohol and benzoic acid had the lowest permeation (P) and diffusion (D) values as compared to the other compounds in the series. This was ascribed to the intermolecular hydrogen bonding potential of benzyl alcohol and benzoic acid; thus the formation of dimer or trimer whose permeation through the polymer is assumed to be restricted. In the case of 4-methylbenzaldehyde and 4-methylacetophenone, the D values obtained were similar to those of the parent compounds (benzaldehyde and acetophenone). Higher P values for the 4-methyl derivatives of benzaldehyde and acetophenone were related to the higher solubility of the molecules in the plastic.