If a subject, who is able to be enrolled in Stage 2, has neurological deficit of ≥4 point on NIHSS score and give patient's consent to participate in the trial, randomization will be performed and each treatment arm (one of three) will be assigned. The subject will receive the Investigational products a total of 6 times, with 12 hours intervals. Blood sample will be taken after the sixth administration of the Investigational product for pharmacokinetic and pharmacodynamics analysis. For pharmacokinetic analysis , blood sample will be taken at 0, 30, and 120 minutes after the complete sixth administration of the investigational products. For pharmacodynamics analysis, blood sample will be taken at between 24 to 48 hours after the first administration, at 0 minute after the sixth administration and at 4th week visit.