frisättningsprofilen

Frisättningsprofilen (the release profile) is a concept in pharmacology and pharmaceutical sciences describing how a drug is released from a dosage form over time under specified conditions. It is typically represented as a cumulative amount or percentage released versus time and is used to characterize and compare formulations, predict in vivo exposure, and guide product development.

In vitro, the release profile is determined by dissolution testing using standard apparatus (for example USP Type I or II) in media that simulate gastric and intestinal fluids. The resulting curve can be analyzed with mathematical models to describe the mechanism of release.

Common models include zero-order (constant release rate), first-order (rate proportional to remaining drug), Higuchi (diffusion-controlled release from a matrix), and Korsmeyer-Peppas (empirical power-law to assess mechanism). For transdermal or implantable systems, additional or alternative models may apply.

Factors influencing frisättningsprofilen include dosage form matrix and excipients, particle size and porosity, manufacturing method, and the geometry of the dosage form. Physiological conditions such as pH, ionic strength, agitation, and the presence of food can alter release. In vivo–in vitro correlations (IVIVC) relate the release profile to actual plasma concentration-time profiles and support regulatory decisions.

Importance and applications: a desirable release profile aims to achieve therapeutic drug levels with controlled peaks and troughs, improve patient adherence, and minimize adverse effects. Release profiles are central to developing immediate, sustained, delayed, or targeted-release formulations.