The patent provides a prefilled syringe for use in treating a patient suffering from a relapsing form of multiple sclerosis, containing 1ml of an aqueous pharmaceutical solution, which has a pH in the range of 5.5-7.0, comprising 40mg/ml of glatiramer acetate and 40 mg/ml of mannitol, the prefilled syringe prepared by the process comprising the steps of:(i) obtaining an aqueous pharmaceutical solution of glatiramer acetate and mannitol；(ii) filtering the aqueous pharmaceutical solution at a temperature from above 0°C up to 17.5°C to produce a filtrate； and(iii) filling a syringe with the filtrate obtained after performing step (ii), so as to thereby prepare a prefilled syringe for use in treating a patient suffering from a relapsing form of multiple sclerosis, containing 1ml of an aqueous pharmaceutical solution, which has a pH in the range of 5.5-7.0, comprising 40mg/ml of glatiramer acetate and 40 mg/ml of mannitol.
