It has been found that the advantages of prefilled syringes can be further enhanced by reducing the size of the air bubble inside the syringe or eliminating it totally. Bubble elimination in a prefilled syringe offers many advantages and after validated studies a new and innovative method is available to fill syringes without the air bubble. Prefilled syringes instead of vials have become the container of choice for parenteral drug delivery. The technique of BUBBLE-FREE FILLING® enhances the benefits of prefilled syringes. The advantages of prefilled syringes are: safety in administration, ease of use, reduced risk of contamination, less waste of costly or scarce API, improved dosing accuracy, and improved sterility assurance. The BUBBLE-FREE FILLING® eliminates stopper movement when the syringe is exposed to reduced atmospheric pressure.