Abstract:Capecitabine is an orally administered chemotherapeutic agent used in the treatment of numerous cancers including colon, colorectal, ovarian, breast and pancreatic. Considering the importance of generic drugs in Health Care Systems, it is essential that its quality, safety and efficacy be compared with the corresponding innovator product. The objective of the study was to compare the pharmacokinetics and relative bioequivalence between two tablet (500 mg) formulations of capecitabine in Mexican patients with cancer of colon. The study was designed as open, prospective, randomized, two-way, crossover bioequivalence trial. A single oral dose of 2000 mg capecitabine was administered on two separate days to 24 patients. After each administration, serial blood samples were collected for up 8 hr. The washout between the two administrations was 3 days. Capecitabine was determined in plasma using LC/MS-MS. No statistically significant differences in C max , AUC 0-t , and AUC 0-α were found between the test and innovator formulations. Both products were well tolerated by the patients, with no serious adverse events. The generic capecitabine was pharmacokinetic bioequivalent with the innovator formulations.