An improved drug delivery device is provided having a piston rod that incorporates on its proximal end at least one guidepost that is configured for transmitting axial and rotational forces from a drive mechanism. The device comprises a drug delivery device housing and a medicament contained in the drug delivery device housing.提供一種改良藥物傳送裝置，其係具有一在近端加上至少一導柱的活塞桿，該至少一導柱係經組態成可用於傳送來自驅動機構的軸向及旋轉力。該裝置包含藥物傳送裝置殼體與內含於該藥物傳送裝置殼體的藥物。
