In vitro methods to study colon release: State of the art and an outlook on new strategies for better in-vitro biorelevant release media

Research output: Contribution to journalReview article


The primary focus of this review is a discussion regarding in vitro media for colon release, but we also give a brief overview of colon delivery and the colon microbiota as a baseline for this discussion. The large intestine is colonized by a vast number of bacteria, approximately 10 12 per gram of intestinal content. The microbial community in the colon is complex and there is still much that is unknown about its composition and the activity of the microbiome. However, it is evident that this complex microbiota will affect the release from oral formulations targeting the colon. This includes the release of active drug substances, food supplements, and live microorganisms, such as probiotic bacteria and bacteria used for microbiota transplantations. Currently, there are no standardized colon release media, but researchers employ in vitro models representing the colon ranging from reasonable simple systems with adjusted pH with or without key enzymes to the use of fecal samples. In this review, we present the pros and cons for different existing in vitro models. Furthermore, we summarize the current knowledge of the colonic microbiota composition which is of importance to the fermentation capacity of carbohydrates and suggest a strategy to choose bacteria for a new more standardized in vitro dissolution medium for the colon.


External organisations
  • Ferring AB
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Pharmaceutical Sciences


  • Colon delivery, Colon microbiota, In vitro systems
Original languageEnglish
Article number95
Issue number2
Publication statusPublished - 2019 Feb 22
Publication categoryResearch