This study will evaluate the drug behavior and safety of a single dose of the 22 milligram tofacitinib (CP-690,550) modified-release formulation in 18 healthy volunteers when taken after eating a high fat meal (the effect of food). This will be compared to the drug behavior and safety of a single dose of the 22 milligram tofacitinib (CP-690,550) modified-release formulation when taken after a 10 hour fast.

Inclusion Criteria:

• Healthy male volunteers and/or healthy female volunteers of non-childbearing potential who are 18 to 55 years of age;
• Healthy volunteers with no evidence of active or latent or inadequately treated tuberculosis.

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease;
• Clinically significant infections within the past 3 months