BIOEQUIVALENCE OF TWO METHOTREXATE FORMULATIONS IN PSORIATIC AND CANCER PATIENTS

OBJEC11VE: To compare the bioequivalence of a generic methotrexate (MTX) tablet (Mylan) with that of a brand-name (Lederle) product. DESIGN: A single-dose, randomized, crossover study. SETTING: Clinical Research Center (CRC) at a university hospital. PATIENTS:Men and women who had a diagnosis of malignancy or psoriasis who were at least 21 years old. METHOOOLOGY: Two overnight study periods were scheduled at the CRC at least one week, but not more than two weeks apart. Each period consisted of a lO-hour fast prior to and 4 hours following oral MTX 15 mg administered as six 2.5-mg tablets. Blood samples were collected over 48 hours. Plasma MTX concentrations were determined using an HPLC assay. Area under the curve from zero to infinity (AUC~) was calculated by the log-trapezoidal method. RESULTS: Twenty-two patients (21 psoriasis, 1 colon cancer) age