Objective: Poorly water-soluble compounds are challenging to formulate to provide therapeutic levels of pharmaceutically active agents. Fenofibrate (FF) is indicated to reduce low-density lipoprotein cholesterol, total cholesterol, triglycerides, and apolipoprotein B, and to increase high-density lipoprotein cholesterol. Since 1998, several formulations of FF have been developed to improve its bioavailability. The purpose of this study is to review and compare FF and fenofibric acid (FA) formulations and identify studies comparing changes in lipid levels between formulations.

Methods: PubMed database was searched from January 1998 to February 2012 using the search terms: fenofibric acid formulations and fenofibrate.

Results: FF is available as nonmicronized, micronized, and nanoparticle formulations. Nonmicronized FF formulations are poorly absorbed and must be taken with meals to maximize absorption. Micronized and nanoparticle formulations have improved bioavailability over nonmicronized formulations, however they differ in regard to food effect. Nanoparticle formulations have reduced particle size compared with micronized formulations and they have significantly increased surface-area-to-volume ratio as well as improved bioavailability. The choline salt of FA is hydrophilic, has no food effect, is absorbed throughout the gastrointestinal tract, and has the highest bioavailability of the marketed formulations. One nanoparticle formulation, two micronized formulations, and several nonmicronized formulations of FF where identified. Low-dose FF is available as 40, 43, 48, 50, 54, and 67 mg dosages. Standard-dose FF is available as 120, 130, 134, 145, 150, 160, and 200 mg dosages. FA formulation is available as 45 and 135 mg dosages. Two studies found improved lipid results in patients who changed from micronized to nanoparticle formulation of FF. No studies have compared lipid changes between FF and FA.

Conclusion: To prevent medication dosing errors resulting in under/over dosing with attendant consequences, it is important for health care providers to recognize that various formulations of FF and FA vary substantially in relation to food effect, equivalency on a milligram per milligram basis, and indication to be coadministered with a statin.