Ready-to-fill, i.e. sterile, prefillable glass syringes, are washed, siliconized, sterilized and packaged by the primary packaging manufacturer. They can then be filled by the pharmaceutical companies without any further processing. These days the majority of prefillable syringes are made of glass and the trend looks set to continue. The siliconization of the syringe barrel is an extremely important aspect of the production of sterile, prefillable glass syringes because the functional interaction of the glass barrel siliconization and the plunger stopper siliconization is crucial to the efficiency of the entire system. Both inadequate and excessive siliconization can cause problems in this connection. The use of modern technology can achieve an extremely uniform distribution of silicone oil in glass syringes with reduced quantities of silicone oil. Another option for minimizing the amount of free silicone oil in a syringe is the thermal fixation of the silicone oil on the glass surface in a process called baked-on siliconization. Plastic-based silicone oil-free or low-silicone oil prefillable syringe systems are a relatively new development. Silicone oil-free lubricant coatings for syringes are also currently in the development phase.