title: Decades of research in drug targeting to the upper gastrointestinal tract using gastroretention technologies: where do we stand?
abstract: A major constraint in oral controlled release drug delivery is that not all the drug candidates are absorbed uniformly throughout the gastrointestinal tract (GIT). Drugs having "absorption window" are absorbed in a particular portion of GIT only or are absorbed to a different extent in various segments of the GIT. Thus, only the drug released in the region preceding and in close vicinity to the absorption window is available for absorption. The drug must be released from the dosage form in solution form; otherwise, it is generally not absorbed. Hence, much research has been dedicated to the development of gastroretentive drug delivery systems that may optimize the bioavailability and subsequent therapeutic efficacy of such drugs, as these systems have unique properties to bypass the gastric emptying process. These systems show excellent in vitro results but fail to give desirable in vivo performance. During the last 2-3 decades, researchers from the academia and industries are giving considerable importance in this field. Unfortunately, till date, few so-called gastroretentive dosage forms have been brought to the market in spite of numerous academic publications. The manuscript considers strategies that are commonly used in the development of gastroretentive drug delivery systems with a special attention on various parameters, which needs to be monitored during formulation development.
authors.affiliation: a Department of Pharmaceutical Science, Research and Development Cell , Jawaharlal Nehru Technological University , Kukatpally, Hyderabad , Andhra Pradesh , India .|b Department of Pharmaceutics , Laureate Institute of Pharmacy , Kathog, Tehsil, Dehra, District Kangra , Himachal Pradesh , India , and.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Awasthi
authors.affiliation: c School of Pharmaceutical Science , ITM University , Gwaliar , Madhya Pradesh , India.
authors.forename: Giriraj T
authors.initials: GT
authors.lastname: Kulkarni
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003692:Delayed-Action Preparations; D004059:Diffusion of Innovation; D004304:Dosage Forms; D004337:Drug Carriers; D004339:Drug Compounding; D065569:Gastrointestinal Absorption; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D011108:Polymers / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000266:history / Q000639:trends*
chemical_list: D003692:Delayed-Action Preparations; D004304:Dosage Forms; D004337:Drug Carriers; D004364:Pharmaceutical Preparations; D011108:Polymers
keywords: Dual working systems; expandable systems; floating drug delivery systems; gastroretentive drug delivery systems; magnetic systems; mucoadhesive systems; superporous systems