Sampling of volunteers is done in Kharazmi Plasma Center in Islamshahr. On the day of sampling, one 40 mg tablet of Sertraliine manufactured by Shafa or Pfizer on two occasions and with a washout period of 14 days, will be administered orally with 240 ml of water to the volunteer. For example, if in the first phase he received the medicine made by Shafa company, he will receive the brand medicine two weeks later. In each phase, 5 cc of blood sample will be taken before drug administration and at times 0, 1, 2, 3, 4, 4.5, 5, 6, 7, 8, 10, 24, 48 and 72 hours after prescribing the medicine. Two weeks after the start of the study, the volunteer's cooperation in this research ends. The way to cooperate in these two weeks is that the drug is prescribed in the first day and after that 72 hours blood sampling is done at the mentioned times after washout period of two weeks the other drug is administered and blood samples will be taken at the same time.