Studi mediante spettroscopia FT-IR su contenitori ad uso farmaceutico internamente siliconati

Pharmaceutical glass containers require high hydrolytic resitance to avoid drug contamination. Moreover hydrophobicity of the innerglass surface is desirable in order to gain a clear draining of the aqueous drug solutions. To improve this characteristic, glass containers are usually treated with silicone oils to create a hydrophobic lubricating film. The siliconization is carried out by spraying diluted aqueous silicone emulsions followed by heat treatment at about 300 °C. It is supposed that the heat-curing treatment probably produces a covalent bond between the silicone film and the glass surface yielding to difficulties in the quantitative silicone oil extraction on the treated glass products. Different siliconized glass containers have been herein investigated before and after a further heat treatment at 400°C. Extractions with an organic solvent and FT- IR spectroscopy have been performed in order to understand the interaction between the silicone oil film and the glass surface, the effect of the temperature on the modifications of the silicone coating and finally to improve the method of silicone coating analysis with FT-IR spectroscopy.