Moisture and oxygen barrier properties of glass, PET and HDPE bottles for pharmaceutical products

Abstract

The purpose of this study was to evaluate the influence of the material and volume/different finish diameters in the moisture and oxygen barrier properties for bottles for pharmaceutical products. Samples of glass, polyethylene terephthalate (PET) and high-density polyethylene (HDPE) bottles with different volumes (30, 60 and 120 cm3) and finish diameters (18, 24 and 28 mm) were studied. It was previously verified that the integrity of the closure was not dependent on the torque applied to the polypropylene (PP) cap and not influence the barrier properties of the bottles. Provided integrity of the cap for all analyzed samples, water vapor transmission rate (WVTR) of glass increased with increase in finish diameter for the same bottle size, due to a large area exposed for moisture permeation through the PP cap. WVTR of PET and HDPE are dependent by the bottle size and its surface area since moisture permeability occurs preferentially by the bottle. The influence of the material in the moisture barrier properties have been confirmed by the WVTR results obtained for the same bottle volume (30cm3/24 mm) with average values of 0.07, 9.9 and 0.8 mg.day−1.bottle−1 at 40 °C/75%RH for glass, PET and HDPE, respectively. Glass represents the greatest oxygen barrier, followed by PET and HDPE for the same bottle size.