Several studies have revealed a definite decrease in the incidence of early graft rejections with the use of MMF. The cost of the drug is, however, prohibitive especially in developing countries with limited resources. We have compared the pharmacokinetic profile of the new MMF generic formulation MMF 500 Batch number: 06T3001 (Medis Tunis) with that of CellCept, Batch number: M1427 (Hoffmann La Roche, Switzerland) in healthy volunteers. The study was double blind (investigator and volunteers), balanced randomized, two-treatment, two-period, two-sequence, single dose, crossover, comparative oral bioavailability study in adult human healthy volunteers. The study was designed, carried out and monitored by the CRO TransMedical s.a.l (Beirut Lebanon) in accordance with the Basic Principals defined in the U.S. 21 CFR Part 312.20, and the principals enunciated in the World Medical Association Declaration of Helsinki. Non-smoking healthy, volunteers, between the ages of 22-45 years, were included. The subjects were admitted to “Hopital” Abou Jaoude Hospital, which is accredited by both the Australian and Lebanese governments, one night prior to blood sampling. All volunteers received the same dinner and were fasted overnight and for 2 hours post dosing. At 8 AM each received a single oral dose of 500 milligrams of either formulation. Blood samples were collected to construct the pharmacokinetic profiles as follows: 0, 0.15, 0.30, 0.45 minutes and, 1, 1.15, 1.30, 2, 4, 6, 10, 12, and 24 hours. Water and food intake was the same for all volunteers during the whole study period. Following 8 days wash out period the subjects were crossed over. Plasma Mycophenolic acid (MPA) concentration was determined using an HPLC validated ELIZA based method (TransMedical, Beirut Lebanon). Physical examinations, hematology, urine analysis, serum chemistry tests and liver enzymes were performed at screening and at the end of each period. Subjects were monitored for safety and adverse events throughout the study by two physicians (one from the hospital and one from TransMedical). The Cmax, T max and AUC for MMF 500 were 10.14 ng/ml, 51.82 minutes and 18.33 ng/ml/h vs. 10.94 ng/ml, 49.09 minutes and 17.46 ng/ml/hour for CellCept respectively which makes the 90% confidence interval (LSM) of Cmax, T max and AUC for MMF 500 to be 92.7%, 105.6% and 105% respectively which is within the FDA assigned range for immunosuppressive drugs (90-111%). These results indicate the both products are equivalent and switchable according to the FDA rulings.