The purpose of this study is to evaluate efficacy and safety of Imotun capsule in osteoarthritis of the knee

This is a six-month, multicenter, randomized, double blind, parallel-group,placebo controlled study. Patients take Imotun capsules or placebo once a day, between the meals. Patients are allowed to take study drugs during the meal in the case of intolerant reflux of oil smell from GI. If patients do not tolerate the pain, they are able to take Celecoxib as a rescue medication during 6 months.

Inclusion Criteria:

• Female and male patients who aged 40 or more and agreement with written informed consent
• Patients with osteoarthritis according to ACR criteria lasted for the past 3 months or more
• Patients with Kellgren & Lawrence grade Ⅱ~Ⅲ on radiographs
• Patients with 40mm or higher 100mm Pain VAS on screening and baseline visit (based on more painful knee)
• Patients with Lequesne's index 5 or more on screening and baseline visit

Exclusion Criteria:

• Patients who had taken SYSADOA within the past 3 months (Imotun, diacerein, s-adenosyl-methionone, JOINS, glucosamine, chondroitin and any other cartilage protective agents determined by investigator)
• Patients who experienced cartilage surgery within the past 5 years or arthroscope surgery within a year(one side or both)
• Patients who were treated with joint space injection within the past 3 months
• Patients who had taken NSAIDs including pain killers within 7 days (except, it is acceptable to enroll the study if the patients have wash out periods at least 7 days before randomization)
• Patients with hypersensitivity or allergy to the study or rescue medicine or those who have medical history.
• Patients with severe liver, kidney or cardiac diseases who are not acceptable for the study determined by investigator
• Patients with active peptic ulcer or GI bleeding.
• Pregnancy, nursing women or women of reproductive age who do not agree to the contraception.
• Patients with abuse of alcohol, illegal drugs or drug dependency
• Patients who were treated with another investigational product within the past 4 weeks
• All other patients who are not acceptable for the study determined by investigator