Comparison of immediate release and extended release formulations in therapy

Abstract

The pharmacokinetics of drugs determine some of the parameters such as the dosing frequency, the route of administration, starting dose, time to reach the steady-state concentration etc. In order to adjust these parameters to provide the ideal administration; modifying the releasing pattern at the absorption site by creating formulations with different drug releasing patterns, such as extended or sustained release is a common practice. As a result; the drug can be applied less frequently, the initiation can be faster without increasing the peak plasma concentration and the steady-state concentration can be reached faster. The possible clinical outcomes are; increasing the efficacy, better tolerability, less variability of pharmacokinetic measures as well as the clinical effects, improving the treatment compliance and lower treatment costs. This article aims to evaluate quetiapine XR (extended release) from this point of view.