Application of silicone oil in the pharmaceutical industry Summary
        Most packaging materials for parenteral administration (such as needles, syringes, rubber stoppers, bottles, etc.) require some surface treatment or lubricating properties to improve process performance and practicability; this article will review the materials used in siliconization and the siliconization process As well as the subsequent sterilization of siliconized items and the removal of silicone oil.
        1 Introduction
        Unless otherwise mentioned, polydimethylsiloxane (PDMS) is currently the most commonly used surface treatment material for parenteral administration packaging materials. PDMS is applied to the inner wall of the glass bottle to facilitate diversion and reduce the surface tension of the glass to promote the homogeneity of the product and prevent the liquid from penetrating the surface of the container (first published in 1950). "Siliconization" or the deposition of a thin film of silicone oil on the surface of glass bottles and rubber stoppers should be the oldest use of silicone oil in the medical field. In the "Application of Silicone Oil in Packaging Materials for Parenteral Administration", there are many examples, such as the application of thin silicone oil coating to siliconize the cleaning of bottles of various specifications, the lubrication of disposable glass syringes, and rubber stoppers. The mechanical lubrication performance of the powder, when the powder needs to be defoamed or degassed after repackaging. In addition, silicone oil films are also used for the lubrication of hypodermic syringes.
        2. Siliconization
        Surface treatment with silicone oil is to spray a solution or emulsion containing silicone oil (by spraying, coating or dipping) on the surface of a clean, dry object with a low concentration. The film can be air-dried or "baked" at high temperatures to enhance the adhesion of the film on the surface. The silicone oil used as packaging materials for parenteral administration should meet certain quality control standards and must not have other harmful effects on the safety, quality, purity and other aspects of the drug.
        Since very little silicone oil is required to cover the surface, it is difficult to quantify the thickness/concentration of the silicone oil film. Some analytical techniques have been successfully used, such as atomic absorption spectrometers. However, users often use functional tests (such as contact angle or friction coefficient) to determine the effect of the coating. In certain circumstances, such as coating on a needle, it is necessary Special test equipment. For example: Melab GmbH has developed a puncture with a cannula head to detect various penetration levels.
        Currently, there are three different types of silicone oil products that can be used for packaging material lubrication: inert silicone oil liquid, inert silicone oil emulsion, and curable silicone oil liquid.