BE Study in Patients - Methotrexate Tablets

Inclusion Criteria: * Patients with mild to severe psoriasis or rheumatoid arthritis, who are already on established regimens of 2.5 mg every 12 hours (7.5 mg per week in three divided doses) * Confirmed diagnosis of psoriasis by clinical examination or after dermatologic consultation. or confirmed diagnosis of mild to severe rheumatoidarthritis based on at least 1 of the following: i. Documented history of positive rheumatoid factor ii. Current presence of rheumatoid factor iii. Radiographic erosion within 12 months prior to enrollment iv. Presence of serum anti-cyclic citrullinated peptide antibodies (anti-CCP). * Women of childbearing potential (include girls who have entered puberty and all women who have a uterus and ovaries and have not completed menopause wherein menopause is the permanent end of menstruation and fertility. Females who have 12 consecutive months of spontaneous amenorrhea (not induced by a medical condition or medical therapy) or have bilateral absence of ovaries (surgical or congenital) have completed menopause must have a negative serum pregnancy test at screening and negative urine pregnancy test on check in to housing, and must agree to use an adequate method of contraception. * Patient's screening laboratory assessment (complete blood count \[CBC\] and blood chemistries) are clinically non-significant as per the discretion of the Investigator. * No history of addiction to any recreational drug or drug dependence. * No participation in any clinical study within the past 60 days prior to receiving the first dose of investigational product for the current study. Exclusion Criteria: * A history of allergic or adverse reactions to Methotrexate Sodium or any related drug or any excipient of methotrexate tablets. * Females of childbearing potential unwilling to use adequate contraception (as defined in the protocol) throughout the trial and for one month after the last dose of study medication. * Males unwilling to use a male condom throughout the trial and for three months after the last dose of study medication * Patients with alcoholism, alcoholic liver disease or other chronic liver disease. * Patients who are diagnosed to be HIV or Hepatitis B (HBsAg) or Hepatitis C (HCV) virus reactive/positive. * Patients who have clinically significant abnormal laboratory values at screening. * Patients with any evidence of organ dysfunction or any clinically significant deviation from normal in their physical or clinical evaluation including ECG and X-ray results except study indication. * Patients who have overt or laboratory evidence of immunodeficiency syndromes. * Patients currently suffering from or having a history of malignant lymphoma or tumor lysis syndrome. * Patients who have pre-existing hematopoietic impairment/ blood dyscrasias, such as bone marrow hypoplasia, aplastic anemia, pancytopenia, leukopenia, neutropenia, thrombocytopenia and or significant anemia. * Patient with lymphadenopathy and lymphoproliferative disorders. * Patients suffering from any acute infection within two weeks prior to randomization. * Patients with a clinically significant past history or current medical condition of: Pulmonary disorders (Pneumonia, COPD and asthma), pleural effusions, Cardiovascular disorders (especially cardiac blocks, pericarditis, pericardial effusion, hypotension and thromboembolic events ), Neurological disorders (especially seizures, migraines), Gastrointestinal tract disorders including a history or presence of significant gastric and/or duodenal ulceration and bleeding, hematemesis, melena, enteritis, pancreatitis, Renal and/or hepatic disorders, Coagulation disorders, Patient with ascites, Patient with uncontrolled diabetes mellitus. * Female patients who are pregnant or breastfeeding * History or presence of cancer. * Evidence of any significant uncontrolled concomitant disease which in the investigator's opinion would exclude the patient participation. * Expected changes in concomitant medications during the period of study. * Tested positive for Alcohol breath or Urine drug of abuse. * Any treatment which could affect the pharmacokinetic of methotrexate (NSAIDs, salicylates, hypoglycemics, diuretics, sulphonamides, diphenylhydantoins, tetracyclines, chloramphenicol and p-aminobenzoic acid, probenecid, penicillins, Chloroquine, omeprazole, etretinate, co-trimoxazole and trimethoprim etc.) administered within 1 month of starting of study. * Patient had major surgery within 4 weeks prior to study entry, or who have not recovered from prior major surgery. * Patients with any significant history of non-compliance to medical regimens or with inability to grant a reliable informed consent. * History of difficulty with donating blood or difficulty in accessibility of veins. * Patients for whom oral administration of drug is not possible. * An unusual or abnormal diet, for whatever reason e.g. religious fasting. * Blood donation/ loss exceeding 200 ml within last 60 days prior to receiving the first dose of investigational product for the current study.