Integrated population pharmacokinetics of etanercept in healthy subjects and in patients with rheumatoid arthritis and ankylosing spondylitis.

Etanercept pharmacokinetics in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriasis were assessed separately with distinct models using population pharmacokinetics methods of limited precision. The different model structures and associated significant covariates identified by these earlier methods made it difficult to compare etanercept pharmacokinetics among disease groups. This integrated analysis aimed to establish a framework to evaluate previously established population pharmacokinetic models of etanercept, and to identify consistent and important demographic and disease factors that affected etanercept pharmacokinetics in a diverse population of healthy subjects and patients with RA and AS.

Liposomal formulations of inflammatory bowel disease drugs: local versus systemic drug delivery in a rat model.

Purpose: Based on adherence to intestinal mucosa, intralumenally administered liposomal formulations of 5-aminosalicylate (5-ASA) and 6-mercaptopurine (6-MP) were studied for their potential to enhance local drug delivery to intestinal tissue for the treatment of inflammatory bowel disease.

Methods: 5-ASA was encapsulated in standard phospholipid liposomes while 6-MP required encapsulation in nonphospholipid liposomes to obtain equivalent drug loading. Encapsulation efficiency was measured by size-exclusion chromatography/high-performance liquid chromatogtaphy (HPLC).