The present invention relates to an injection device for injecting a pharmaceutical liquid drug containing a preservative. The injection device comprises a housing (1) supporting a cartridge (20) having an interior chamber (21) holding the pharmaceutical preservative containing liquid drug to be injected, and a needle cannula (10) having a front part (11) and a back part (12), which back part (12) is adapted to be in liquid communication with the interior chamber (21) of the cartridge (20). The injection device is further provided with a telescopic needle covering shield (30) which distally is provided with a reservoir (31) which holds a liquid containing the same preservatives as in the pharmaceutical preservative containing liquid drug contained in the interior chamber of the cartridge. The telescopic needle covering shield (30) is telescopic movable in relation to the needle cannula (10) by a first resilient member between a first position and a second position. In the first position, the tip (13) of the front part (11) of the needle cannula (10) is maintained inside the reservoir (31), and in the second position, the tip (13) of the front part (11) of the needle cannula (10) is located outside the reservoir (31) and distally to the reservoir (31). The tip (13) of the needle cannula (10) is thus cleaned by the preservatives in the reservoir (31) between subsequent injections.Buluş tercihen bir iğne kanülü ile birlikte olan bir enjeksiyon kalemi gibi bir enjeksiyon cihazı ile ilgilidir. Buluş özellikle içerisinde aynı iğne kanülünün art arda birçok enjeksiyon için kullanıldığı ve enjeksiyonlar arasında otomatik olarak temizlendiği türdeki enjeksiyon cihazı ile ilgilidir. Ayrıca buluş bu türde enjeksiyon cihazını hazırlamanın bir metodu ile ilgilidir.
