Abstract: A prefilled syringe provides two mechanisms by which the viscosity difference between the drug-filled syringe and the placebo-filled syringe can be masked, then maintain the blindness throughout the complete clinical trials. The first mechanism is to have different thread sizes that can generate different friction forces to offset the injection force difference due to the viscosity difference between the drug and the placebo. The second mechanism is to have a plunger rod with two components, which can be assembled at different positions and generate different friction force to offset the injection force between the drug and the placebo.

Abstract: The present invention relates to a pharmaceutical composition containing ilaprazole or a salt thereof, and a preparation method therefor. The pharmaceutical composition contains or consists of ilaprazole or a salt thereof, and a ilaprazole derivative, wherein the amount of the ilaprazole derivative in the pharmaceutical composition is not higher than 1.3 wt % (less than or equal to 1.3 wt %). The composition can be used for treating peptic ulcer bleeding and stress ulcer and preventing upper gastrointestinal hemorrhage caused by severe diseases.